Tucatinib: Drug information

Dosing: Adult

Breast cancer, HER2-positive, advanced unresectable or metastatic

Breast cancer, HER2-positive, advanced unresectable or metastatic: Oral: 300 mg twice daily (in combination with trastuzumab and capecitabine) until disease progression or unacceptable toxicity (Ref).

Colorectal cancer, RAS wild-type, HER2-positive, unresectable or metastatic

Colorectal cancer, RAS wild-type, HER2- positive, unresectable or metastatic: Oral: 300 mg twice daily (in combination with trastuzumab) until disease progression or unacceptable toxicity (Ref).

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Missed dose: If a dose is missed or vomited, administer the next dose at its usual time.

Dosing: Kidney Impairment: Adult

Note: CrCl calculated by Cockcroft-Gault equation.

CrCl ≥30 mL/minute: No dosage adjustment necessary.

CrCl <30 mL/minute: The effect of severe kidney impairment on tucatinib pharmacokinetics is not known. Per the tucatinib manufacturer, the use of tucatinib in combination with capecitabine and trastuzumab is not recommended. Refer to Capecitabine monograph for further information.

Dosing: Hepatic Impairment: Adult

Hepatic impairment at treatment initiation:

Mild or moderate impairment (Child-Pugh class A or B): No initial dosage adjustment necessary.

Severe impairment (Child-Pugh class C): Reduce initial dose to 200 mg twice daily.

Hepatotoxicity during treatment:

**Tucatinib Dosage Adjustment for Hepatotoxicity During Treatment**
Toxicity/Severity	Tucatinib Dose Modification^a
^aSee recommended tucatinib dosage reduction levels in Dosing Adjustment for Toxicity. Trastuzumab and/or capecitabine may also require dosage modification.
Grade 2 bilirubin elevation (>1.5 to 3 times ULN)	Hold tucatinib until recovery to ≤ grade 1, then resume tucatinib at the same dose level.
Grade 3 ALT or AST elevation (>5 to 20 times ULN) or grade 3 bilirubin elevation (>3 to 10 times ULN)	Hold tucatinib until recovery to ≤ grade 1, then resume tucatinib at the next lower dose level.
Grade 4 ALT or AST elevation (>20 times ULN) or grade 4 bilirubin elevation (>10 times ULN)	Permanently discontinue tucatinib.
ALT or AST elevation >3 times ULN AND bilirubin elevation >2 times ULN	Permanently discontinue tucatinib.

Dosing: Adjustment for Toxicity: Adult

**Recommended Tucatinib Dosage Reduction Levels**
Initial (usual) dose	300 mg twice daily
First dose reduction level	250 mg twice daily
Second dose reduction level	200 mg twice daily
Third dose reduction level	150 mg twice daily
Permanently discontinue tucatinib if unable to tolerate 150 mg twice daily.

**Tucatinib Dosage Adjustment for Toxicities**
Toxicity	Severity	Tucatinib dose modification^a
^aTrastuzumab and/or capecitabine may also require dosage modification.
Diarrhea	If diarrhea occurs, administer antidiarrheal treatment as clinically indicated; perform diagnostic tests as needed to exclude other causes of diarrhea.
	Grade 3, without antidiarrheal treatment	Initiate or intensify appropriate medical therapy. Hold tucatinib until recovery to ≤ grade 1, then resume tucatinib at the same dose level.
	Grade 3, with antidiarrheal treatment	Initiate or intensify appropriate medical therapy. Hold tucatinib until recovery to ≤ grade 1, then resume tucatinib at the next lower dose level.
	Grade 4	Permanently discontinue tucatinib.
Other adverse reactions	Grade 3	Hold tucatinib until recovery to ≤ grade 1, then resume tucatinib at the next lower dose level.
Other adverse reactions	Grade 4	Permanently discontinue tucatinib.

Dosing: Older Adult

Refer to adult dosing.

Adverse Reactions (Significant): Considerations

GI toxicity

Tucatinib may commonly cause diarrhea, including severe diarrhea accompanied by dehydration, hypotension, acute kidney injury, and may be fatal. While grade 1 and grade 2 occurred in the majority of patients (Ref), grade 4 diarrhea was considered a contributing factor in patients who subsequently died. Mild cases of nausea, vomiting, and stomatitis have also occurred. Diarrhea, nausea, and vomiting were the most common serious adverse reactions in patients ≥65 years of age.

Mechanism: Dose-related; exact mechanism is not established.

Onset: Intermediate; median time to onset of the first diarrhea episode was 12 days; median time to resolution was 8 days. In patients who utilized antidiarrheal medications, the median duration of use was 3 days per cycle (Ref).

Hepatotoxicity

May commonly cause hepatotoxicity, including severe hepatotoxicity with ≥ grade 3 increased serum alanine aminotransferase (ALT), increased serum aspartate aminotransferase (AST), and increased serum bilirubin. Most increases to serum ALT and increased serum AST levels were low grade, transient, and reversible (Ref).

Risk factors:

• Preexisting severe hepatic impairment

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Incidences reported for combination therapy with trastuzumab with or without capecitabine.

>10%:

Cardiovascular: Hypertension (17%)

Dermatologic: Palmar-plantar erythrodysesthesia (63%), skin rash (20% to 37%)

Endocrine & metabolic: Decreased serum albumin (24%), decreased serum magnesium (40%), decreased serum phosphate (57%), decreased serum potassium (16% to 36%), decreased serum sodium (20% to 28%), increased serum glucose (56%), weight loss (7% to 13%)

Gastrointestinal: Abdominal pain (21%; severe abdominal pain: 2%), constipation (14%), decreased appetite (19% to 25%), diarrhea (64% to 81%; grade 3: 4% to 12%; grade 4: <1%) (table 1)Diarrhea, nausea (35% to 58%; grade 3: 4%) (table 2)Nausea, stomatitis ((1% to 32%; grade 3: 3%) (table 3)Stomatitis, vomiting (16% to 36%; grade 3: 3%) (table 4)Vomiting

**Tucatinib: Adverse Reaction: Diarrhea**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
All grades: 81%	N/A	53%	HER2-positive metastatic breast cancer	404	N/A	197
Grade 3: 12%	N/A	9%	HER2-positive metastatic breast cancer	404	N/A	197
Grade 4: 0.5%	N/A	0%	HER2-positive metastatic breast cancer	404	N/A	197
N/A	All grades: 64%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A
N/A	Grade 3: 4%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A

**Tucatinib: Adverse Reaction: Nausea**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
All grades: 58%	N/A	44%	HER2-positive metastatic breast cancer	404	N/A	197
Grade 3: 4%	N/A	3%	HER2-positive metastatic breast cancer	404	N/A	197
N/A	All grades: 35%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A

**Tucatinib: Adverse Reaction: Stomatitis**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
All grades: 32%	N/A	21%	HER2-positive metastatic breast cancer	404	N/A	197
Grade 3: 3%	N/A	0.5%	HER2-positive metastatic breast cancer	404	N/A	197
N/A	All grades: 1%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A

**Tucatinib: Adverse Reaction: Vomiting**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
All grades: 36%	N/A	25%	HER2-positive metastatic breast cancer	404	N/A	197
Grade 3: 3%	N/A	4%	HER2-positive metastatic breast cancer	404	N/A	197
N/A	All grades: 16%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A

Hematologic & oncologic: Anemia (10% to 21%; grade 3: 4%), decreased platelet count (15%), leukopenia (22%), lymphocytopenia (39%; grade 3: 12%)

Hepatic: Hepatotoxicity (42%) (table 5)Hepatotoxicity, increased serum alanine aminotransferase (46%; >5 × ULN: 5% to 8%) (table 6), increased serum alkaline phosphatase (25% to 26%), increased serum aspartate aminotransferase (33% to 43%; >5 × ULN: 6%) (table 7), increased serum bilirubin (28% to 47%) (table 8)Increased Serum Bilirubin

**Tucatinib: Adverse Reaction: Hepatotoxicity**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
42%	24%	HER2-positive metastatic breast cancer	404	197

**Tucatinib: Adverse Reaction: Increased Serum Alanine Aminotransferase**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)	Comments
All grades: 46%	N/A	27%	HER2-positive metastatic breast cancer	404	N/A	197	N/A
Grades ≥3: 8%	N/A	0.5%	HER2-positive metastatic breast cancer	404	N/A	197	>5 × ULN
N/A	All grades: 46%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A	N/A
N/A	Grades ≥3: 5%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A	>5 × ULN

**Tucatinib: Adverse Reaction: Increased Serum Aspartate Aminotransferase**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)	Comments
All grades: 43%	N/A	25%	HER2-positive metastatic breast cancer	404	N/A	197	N/A
Grades ≥3: 6%	N/A	1%	HER2-positive metastatic breast cancer	404	N/A	197	>5 × ULN
N/A	All grades: 33%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A	N/A
N/A	Grades ≥3: 6%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A	>5 × ULN

**Tucatinib: Adverse Reaction: Increased Serum Bilirubin**
Drug (Tucatinib + Trastuzumab + Capecitabine)	Drug (Tucatinib + Trastuzumab)	Comparator (Placebo + Trastuzumab + Capecitabine)	Indication	Number of Patients (Tucatinib + Trastuzumab + Capecitabine)	Number of Patients (Tucatinib + Trastuzumab)	Number of Patients (Placebo + Trastuzumab + Capecitabine)
47%	N/A	30%	HER2-positive metastatic breast cancer	404	N/A	197
N/A	28%	N/A	RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer	N/A	86	N/A

Hypersensitivity: Infusion-related reaction (21%)

Nervous system: Chills (19%), fatigue (44%), peripheral neuropathy (including peripheral motor neuropathy, peripheral sensory neuropathy, and sensorimotor neuropathy [peripheral]:13%; grade 3: <1%)

Neuromuscular & skeletal: Arthralgia (15% to 16%), back pain (17%), myalgia (13%)

Renal: Increased serum creatinine (14% to 58%; inhibits renal tubular secretion, no effect on GFR) (Topletz-Erickson 2020)

Respiratory: Cough (16%), dyspnea (14%), epistaxis (7% to 12%)

Miscellaneous: Fever (20%)

1% to 10%:

Gastrointestinal: Gastrointestinal perforation (rectal) (2%), intestinal obstruction (serious: 7%)

Genitourinary: Urinary tract infection (serious: 4%)

Nervous system: Anxiety (10%), dysesthesia (oral) (1%), seizure (2%)

Respiratory: Oropharyngeal pain (5%), pneumonia (serious: 2%)

Contraindications

There are no contraindications listed in the manufacturer's US labeling.

Canadian labeling: Hypersensitivity to tucatinib or any component of the formulation.

Warnings/Precautions

Disease-related concerns:

• Serum creatinine increases: Tucatinib increases serum creatinine by inhibiting kidney tubular secretion, but without affecting glomerular filtration (Murthy 2020; Topletz-Erickson 2020). Serum creatinine elevations initially occurred within the first 3 weeks of treatment (and persisted throughout treatment) and were reversible upon completion of therapy. If persistent serum creatinine elevations are observed, consider alternative markers for kidney function evaluation.

Special populations:

• Older adult: The incidence of serious adverse reactions was higher in patients ≥65 years of age compared to younger patients.

Other warnings/precautions:

• Appropriate use: Select patients with colorectal cancer for treatment based on the presence of HER2 overexpression or gene amplification and RAS wild-type. Information on tests for the detection of mutations is available at http://www.fda.gov/CompanionDiagnostics. Patients with breast cancer should have HER2-positive tumors.

Dosage Forms: US

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Tukysa: 50 mg, 150 mg

Generic Equivalent Available: US

No

Pricing: US

Tablets (Tukysa Oral)

50 mg (per each): $127.46

150 mg (per each): $256.30

Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.

Dosage Forms: Canada

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Tukysa: 50 mg, 150 mg

Administration: Adult

Oral: Administer approximately every 12 hours, with or without food. Swallow tablets whole; do not chew, crush, or split; patients should not ingest tablets that are broken, cracked, or not otherwise intact. May administer tucatinib at the same time as capecitabine in the days that capecitabine is also scheduled.

Use: Labeled Indications

Breast cancer, HER2-positive, advanced unresectable or metastatic: Treatment of advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer (in combination with trastuzumab and capecitabine) in adults, including patients with brain metastases, who have received 1 or more prior anti-HER2-based regimens in the metastatic setting.

Colorectal cancer, RAS wild-type, HER2-positive, unresectable or metastatic: Treatment of RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer (in combination with trastuzumab) that has progressed following treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy in adults.

Medication Safety Issues

Sound-alike/look-alike issues:

Tucatinib may be confused with afatinib, dasatinib, lapatinib, neratinib, talazoparib, tofacitinib, trametinib.

High alert medication:

This medication is in a class the Institute for Safe Medication Practices included among its lists of drug classes that have a heightened risk of causing significant patient harm when used in error.

Metabolism/Transport Effects

Substrate of BCRP/ABCG2, CYP2C8 (major), CYP3A4 (minor); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits CYP2C8 (weak), CYP3A4 (strong), OCT2, P-glycoprotein/ABCB1

Drug Interactions

Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the Lexicomp drug interactions program by clicking on the “Launch drug interactions program” link above.

Abemaciclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Abemaciclib. Management: In patients taking abemaciclib at a dose of 200 mg or 150 mg twice daily, reduce the dose to 100 mg twice daily when combined with strong CYP3A4 inhibitors. In patients taking abemaciclib 100 mg twice daily, decrease the dose to 50 mg twice daily. Risk D: Consider therapy modification

Acalabrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Acalabrutinib. Risk X: Avoid combination

Adagrasib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Adagrasib. Management: Avoid use of adagrasib and strong CYP3A4 inhibitors until adagrasib concentrations have reached steady state (ie, after approximately 8 days of therapy). Risk D: Consider therapy modification

Ado-Trastuzumab Emtansine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ado-Trastuzumab Emtansine. Specifically, strong CYP3A4 inhibitors may increase concentrations of the cytotoxic DM1 component. Management: Avoid concomitant use of ado-trastuzumab emtansine and strong CYP3A4 inhibitors when possible. Consider alternatives that do not inhibit CYP3A4 or consider administering after CYP3A4 inhibitor discontinuation. Monitor for toxicities if combined. Risk D: Consider therapy modification

Afatinib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Afatinib. Management: If combined, administer the P-gp inhibitor simultaneously with, or after, the dose of afatinib. Monitor closely for signs and symptoms of afatinib toxicity and if the combination is not tolerated, reduce the afatinib dose by 10 mg. Risk D: Consider therapy modification

ALfentanil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ALfentanil. Management: If use of alfentanil and strong CYP3A4 inhibitors is necessary, consider dosage reduction of alfentanil until stable drug effects are achieved. Frequently monitor patients for respiratory depression and sedation when these agents are combined. Risk D: Consider therapy modification

Alfuzosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alfuzosin. Risk X: Avoid combination

Aliskiren: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Aliskiren. Risk C: Monitor therapy

Alitretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alitretinoin (Systemic). Management: Consider reducing the alitretinoin dose to 10 mg when used together with strong CYP3A4 inhibitors. Monitor for increased alitretinoin effects/toxicities if combined with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Almotriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Almotriptan. Management: Limit initial almotriptan dose to 6.25 mg and maximum dose to 12.5 mg in any 24-period when used with a strong CYP3A4 inhibitor. Avoid concurrent use in patients with impaired hepatic or renal function. Risk D: Consider therapy modification

Alosetron: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alosetron. Risk C: Monitor therapy

ALPRAZolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ALPRAZolam. Risk X: Avoid combination

Amiodarone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Amiodarone. Management: Consider alternatives to use of amiodarone and strong CYP3A4 inhibitors. If combined, monitor for increased amiodarone concentrations and toxicities. Risk D: Consider therapy modification

AmLODIPine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of AmLODIPine. Risk C: Monitor therapy

Apixaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Apixaban. Management: US labeling recommends a 50% apixaban dose reduction in patients who would otherwise receive 5 or 10 mg twice daily, and avoiding in patients who would otherwise receive 2.5 mg twice daily. Canadian labeling lists any combined use as contraindicated. Risk D: Consider therapy modification

Aprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Aprepitant. Risk X: Avoid combination

ARIPiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ARIPiprazole. Management: Aripiprazole dose reductions are required for indications other than major depressive disorder. Dose reductions vary based on formulation, initial starting dose, CYP2D6 genotype, and use of CYP2D6 inhibitors. See full interaction monograph for details. Risk D: Consider therapy modification

ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Decrease aripiprazole lauroxil dose to next lower strength if used with strong CYP3A4 inhibitors for over 14 days. No dose adjustment needed if using the lowest dose (441 mg). Max dose is 441 mg in CYP2D6 PMs or if also taking strong CYP2D6 inhibitors. Risk D: Consider therapy modification

Artemether and Lumefantrine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Artemether and Lumefantrine. Specifically, concentrations of dihydroartemisinin (DHA), the active metabolite of artemether may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Artemether and Lumefantrine. Risk C: Monitor therapy

Asciminib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Asciminib. Risk C: Monitor therapy

Astemizole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Astemizole. Risk X: Avoid combination

Asunaprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Asunaprevir. Risk X: Avoid combination

Atazanavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Atazanavir. Risk C: Monitor therapy

Atogepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Atogepant. Management: For treatment of episodic migraine, the recommended atogepant dose is 10 mg once daily with a concurrent strong CYP3A4 inhibitor. If used for treatment of chronic migraine, concurrent use of atogepant with strong CYP3A4 inhibitors should be avoided. Risk D: Consider therapy modification

Atorvastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Atorvastatin. Risk C: Monitor therapy

Avacopan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avacopan. Management: Decrease the avacopan dose to 30 mg once daily during coadministration with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Avanafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avanafil. Risk X: Avoid combination

Avapritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avapritinib. Risk X: Avoid combination

Axitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Axitinib. Management: Avoid concurrent use of axitinib with any strong CYP3A inhibitor whenever possible. If a strong CYP3A inhibitor must be used with axitinib, a 50% axitinib dose reduction is recommended. Risk D: Consider therapy modification

Barnidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Barnidipine. Risk X: Avoid combination

Beclomethasone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Beclomethasone (Systemic). Risk C: Monitor therapy

Bedaquiline: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Bedaquiline. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bedaquiline. Management: Limit duration of concurrent use of bedaquiline with strong CYP3A4 inhibitors to no more than 14 days, unless the benefit of continued use outweighs the possible risks. Monitor for toxic effects of bedaquiline, including QTc interval prolongation. Risk D: Consider therapy modification

Benidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benidipine. Risk C: Monitor therapy

Benperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benperidol. Risk C: Monitor therapy

Benzhydrocodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Risk C: Monitor therapy

Berotralstat: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Berotralstat. Management: Decrease the berotralstat dose to 110 mg daily when combined with P-glycoprotein (P-gp) inhibitors. Risk D: Consider therapy modification

Betamethasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Nasal). Risk C: Monitor therapy

Betamethasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Ophthalmic). Risk C: Monitor therapy

Betamethasone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Systemic). Risk C: Monitor therapy

Betamethasone (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Topical). Risk C: Monitor therapy

Bilastine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Bilastine. Risk X: Avoid combination

Blonanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Blonanserin. Risk X: Avoid combination

Bortezomib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bortezomib. Risk C: Monitor therapy

Bosentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosentan. Risk C: Monitor therapy

Bosutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosutinib. Risk X: Avoid combination

Brentuximab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor therapy

Brexpiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brexpiprazole. Management: Reduce brexpiprazole dose 50% with strong CYP3A4 inhibitors; reduce to 25% of usual if used with both a strong CYP3A4 inhibitor and a CYP2D6 inhibitor in patients not being treated for MDD, or strong CYP3A4 inhibitor used in a CYP2D6 poor metabolizer. Risk D: Consider therapy modification

Brigatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with strong CYP3A4 inhibitors when possible. If combination cannot be avoided, reduce the brigatinib dose by approximately 50%, rounding to the nearest tablet strength (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). Risk D: Consider therapy modification

Bromocriptine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bromocriptine. Management: Consider alternatives to the use of bromocriptine with strong CYP3A4 inhibitors. If combined, monitor closely for increased bromocriptine toxicities and consider bromocriptine dose reductions. Risk D: Consider therapy modification

Bromperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bromperidol. Risk C: Monitor therapy

Brotizolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brotizolam. Risk C: Monitor therapy

Budesonide (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Nasal). Risk C: Monitor therapy

Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Oral Inhalation). Management: Consider alternatives to this combination when possible. If combined, monitor for increased corticosteroid adverse effects during coadministration of inhaled budesonide and strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Budesonide (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Systemic). Management: Avoid the concomitant use of CYP3A4 inhibitors and oral budesonide. If patients receive both budesonide and a strong CYP3A4 inhibitor, they should be closely monitored for signs and symptoms of corticosteroid excess. Risk D: Consider therapy modification

Budesonide (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Topical). Risk X: Avoid combination

Buprenorphine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Buprenorphine. Risk C: Monitor therapy

BusPIRone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of BusPIRone. Management: Limit the buspirone dose to 2.5 mg daily and monitor patients for increased buspirone effects/toxicities if combined with strong CYP3A4 inhibitors. Dose adjustments of buspirone or a strong CYP3A4 inhibitor should be based on clinical assessment. Risk D: Consider therapy modification

Butorphanol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Butorphanol. Risk C: Monitor therapy

Cabazitaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabazitaxel. Management: Concurrent use of cabazitaxel with strong inhibitors of CYP3A4 should be avoided when possible. If such a combination must be used, consider a 25% reduction in the cabazitaxel dose. Risk D: Consider therapy modification

Cabozantinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabozantinib. Management: Avoid use of a strong CYP3A4 inhibitor with cabozantinib if possible. If combined, decrease cabozantinib capsules (Cometriq) by 40 mg from previous dose or decrease cabozantinib tablets (Cabometyx) by 20 mg from previous dose. Risk D: Consider therapy modification

Calcifediol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Calcifediol. Risk C: Monitor therapy

Calcitriol (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Calcitriol (Systemic). Risk C: Monitor therapy

Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabidiol. Risk C: Monitor therapy

Cannabis: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Risk C: Monitor therapy

Capivasertib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Capivasertib. Management: Avoid concomitant use of capivasertib with strong CYP3A4 inhibitors when possible. If combined, reduce the capivasertib dose to 320 mg twice daily for 4 days, followed by 3 days off. Monitor patients closely for adverse reactions. Risk D: Consider therapy modification

Capmatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Capmatinib. Risk C: Monitor therapy

Cariprazine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Cariprazine. Specifically, concentrations of didesmethylcariprazine (DDCAR), the primary active metabolite of cariprazine, may increase. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cariprazine. Management: Decrease cariprazine dose 50% (4.5 mg to 1.5 mg or 3 mg; 1.5 mg to 1.5 mg every other day) if starting a strong CYP3A4 inhibitor. If on a strong CYP3A4 inhibitor, start cariprazine at 1.5 mg day 1, 0 mg day 2, then 1.5 mg daily. May increase to 3 mg daily Risk D: Consider therapy modification

Celiprolol: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Celiprolol. Risk C: Monitor therapy

Ceritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ceritinib. Management: Avoid this combination whenever possible. If combined, the ceritinib dose should be reduced by approximately one-third (to the nearest 150 mg). Resume the prior ceritinib dose after cessation of the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

ChlordiazePOXIDE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ChlordiazePOXIDE. Risk C: Monitor therapy

Ciclesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ciclesonide (Oral Inhalation). Risk C: Monitor therapy

Cilnidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cilnidipine. Risk C: Monitor therapy

Cilostazol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cilostazol. Management: Decrease the dose of cilostazol to 50 mg twice daily when combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Cinacalcet: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cinacalcet. Risk C: Monitor therapy

Cisapride: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cisapride. Risk X: Avoid combination

Clarithromycin: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Clarithromycin. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Clarithromycin. Risk C: Monitor therapy

Clindamycin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Clindamycin (Systemic). Risk C: Monitor therapy

Clofarabine: OCT2 Inhibitors may increase the serum concentration of Clofarabine. Risk C: Monitor therapy

ClonazePAM: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ClonazePAM. Risk C: Monitor therapy

CloZAPine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of CloZAPine. Risk C: Monitor therapy

Cobicistat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cobicistat. Risk C: Monitor therapy

Cobimetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cobimetinib. Risk X: Avoid combination

Codeine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Codeine. Risk C: Monitor therapy

Colchicine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Colchicine. Management: This combination is often contraindicated, but combined use may be permitted with dose adjustment and monitoring. Recommendations vary based on brand, indication, use of P-gp inhibitors, and hepatic/renal function. See interaction monograph for details Risk D: Consider therapy modification

Colchicine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Colchicine. Colchicine distribution into certain tissues (e.g., brain) may also be increased. Management: This combination is often contraindicated, but combined use may be permitted with dose adjustment and monitoring. Recommendations vary based on brand, indication, use of CYP3A4 inhibitors, and hepatic/renal function. See interaction monograph for details. Risk D: Consider therapy modification

Conivaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Conivaptan. Risk X: Avoid combination

Copanlisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Copanlisib. Management: If concomitant use of copanlisib and strong CYP3A4 inhibitors cannot be avoided, reduce the copanlisib dose to 45 mg. Monitor patients for increased copanlisib effects/toxicities. Risk D: Consider therapy modification

Cortisone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cortisone. Risk C: Monitor therapy

Crizotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Crizotinib. Management: Avoid concomitant use of crizotinib and strong CYP3A4 inhibitors whenever possible. If combined use cannot be avoided, crizotinib dose reductions are required, which vary according to indication. See full interaction monograph for details. Risk D: Consider therapy modification

CycloSPORINE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of CycloSPORINE (Systemic). Management: Monitor cyclosporine serum concentrations and clinical cyclosporine closely with concurrent use of any strong CYP3A4 inhibitor. Cyclosporine dose reductions and/or prolongation of the dosing interval will likely be required. Risk D: Consider therapy modification

CYP2C8 Inducers (Moderate): May decrease the serum concentration of Tucatinib. Risk X: Avoid combination

CYP2C8 Inhibitors (Moderate): May increase the serum concentration of Tucatinib. Risk C: Monitor therapy

CYP2C8 Inhibitors (Strong): May increase the serum concentration of Tucatinib. Management: Combined use not recommended. If the combo cannot be avoided, reduce tucatinib to 100 mg twice daily. After stopping the strong CYP2C8 inhibitor, wait 3 half-lives of the discontinued inhibitor and resume the tucatinib dose taken prior to the inhibitor. Risk D: Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of Tucatinib. Risk C: Monitor therapy

CYP3A4 Inducers (Strong): May decrease the serum concentration of Tucatinib. Risk X: Avoid combination

Cyproterone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cyproterone. Risk C: Monitor therapy

Dabigatran Etexilate: P-glycoprotein/ABCB1 Inhibitors may increase serum concentrations of the active metabolite(s) of Dabigatran Etexilate. Risk C: Monitor therapy

Dabrafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dabrafenib. Management: Consider alternatives to any strong CYP3A4 inhibitor for patients being treated with dabrafenib. If such a combination cannot be avoided, monitor closely for evidence of dabrafenib-related adverse effects. Risk D: Consider therapy modification

Daclatasvir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Daclatasvir. Management: Decrease the daclatasvir dose to 30 mg once daily if combined with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Dalfampridine: OCT2 Inhibitors may increase the serum concentration of Dalfampridine. Management: Consider alternatives to this combination. Carefully weigh the risk of seizures against the benefit of combining OCT2 inhibitors with dalfampridine. Risk D: Consider therapy modification

Dapoxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dapoxetine. Risk X: Avoid combination

Daprodustat: CYP2C8 Inhibitors (Weak) may increase the serum concentration of Daprodustat. Risk C: Monitor therapy

Daridorexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Daridorexant. Risk X: Avoid combination

Darifenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Darifenacin. Management: Limit the darifenacin dose to no more than 7.5 mg daily if combined with strong CYP3A4 inhibitors. Monitor patients for increased darifenacin toxicities (eg, dry mouth, constipation, headache, CNS effects) when these agents are combined. Risk D: Consider therapy modification

Darolutamide: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Darolutamide. Risk C: Monitor therapy

Darunavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Darunavir. Risk C: Monitor therapy

Dasatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dasatinib. Management: This combination should be avoided if possible. If combined, decrease dasatinib dose from 140 mg to 40 mg, 100 mg to 20 mg, or 70 mg to 20 mg. For patients taking 60 mg or 40 mg daily, stop dasatinib until the CYP3A4 inhibitor is discontinued. Risk D: Consider therapy modification

Deflazacort: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Deflazacort. Management: Administer one third of the recommended deflazacort dose when used together with a strong or moderate CYP3A4 inhibitor. Risk D: Consider therapy modification

Delamanid: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Delamanid. Management: Increase ECG monitoring frequency if delamanid is combined with strong CYP3A4 inhibitors due to the risk for QTc interval prolongation. Continue frequent ECG assessments throughout full delamanid treatment period. Risk D: Consider therapy modification

DexAMETHasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DexAMETHasone (Ophthalmic). Risk C: Monitor therapy

DexAMETHasone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DexAMETHasone (Systemic). Risk C: Monitor therapy

DiazePAM: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DiazePAM. Risk C: Monitor therapy

Dienogest: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dienogest. Risk C: Monitor therapy

Digoxin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Digoxin. Management: Measure digoxin serum concentrations before initiating treatment with these P-glycoprotein (P-gp) inhibitors. Reduce digoxin concentrations by either reducing the digoxin dose by 15% to 30% or by modifying the dosing frequency. Risk D: Consider therapy modification

DilTIAZem: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DilTIAZem. Risk C: Monitor therapy

Disopyramide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Disopyramide. Risk C: Monitor therapy

DOCEtaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOCEtaxel. Management: Avoid the concomitant use of docetaxel and strong CYP3A4 inhibitors when possible. If combined use is unavoidable, consider a 50% docetaxel dose reduction and monitor for increased docetaxel toxicities. Risk D: Consider therapy modification

Dofetilide: MATE1/2-K Inhibitors may increase the serum concentration of Dofetilide. Risk X: Avoid combination

Domperidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Domperidone. Risk X: Avoid combination

Doxazosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Doxazosin. Risk C: Monitor therapy

Doxercalciferol: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Doxercalciferol. Risk C: Monitor therapy

DOXOrubicin (Conventional): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of DOXOrubicin (Conventional). Risk X: Avoid combination

DOXOrubicin (Liposomal): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of DOXOrubicin (Liposomal). Risk C: Monitor therapy

DroNABinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DroNABinol. Risk C: Monitor therapy

Dronedarone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dronedarone. Risk X: Avoid combination

Dutasteride: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dutasteride. Risk C: Monitor therapy

Duvelisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Duvelisib. Management: Reduce the dose of duvelisib to 15 mg twice a day when used together with a strong CYP3A4 inhibitor. Monitor closely for evidence of altered response to treatment. Risk D: Consider therapy modification

Dydrogesterone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dydrogesterone. Risk C: Monitor therapy

Ebastine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ebastine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ebastine. Risk C: Monitor therapy

Edoxaban: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Edoxaban. Risk C: Monitor therapy

Efonidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Efonidipine. Risk C: Monitor therapy

Elacestrant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elacestrant. Risk X: Avoid combination

Elagolix: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elagolix. Management: Use of the elagolix 200 mg twice daily dose with a strong CYP3A4 inhibitor for longer than 1 month is not recommended. Limit combined use of the elagolix 150 mg once daily dose with a strong CYP3A4 inhibitor to a maximum of 6 months. Risk D: Consider therapy modification

Elagolix, Estradiol, and Norethindrone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elagolix, Estradiol, and Norethindrone. Elagolix, Estradiol, and Norethindrone may decrease the serum concentration of CYP3A4 Inhibitors (Strong). Specifically, concentrations of strong CYP3A4 inhibitors that are also CYP3A4 substrates may be decreased. Risk X: Avoid combination

Elbasvir and Grazoprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elbasvir and Grazoprevir. Management: Consider alternatives to this combination when possible. If combined, monitor for increased elbasvir/grazoprevir toxicities, including ALT elevations. Risk D: Consider therapy modification

Eletriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eletriptan. Risk X: Avoid combination

Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: Administer elexacaftor/tezacaftor/ivacaftor in the morning, twice a week, 3 to 4 days apart, with no evening doses of ivacaftor alone. Specific dosing varies by age and weight. See full monograph for details. Risk D: Consider therapy modification

Eliglustat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eliglustat. Management: Reduce eliglustat dose to 84 mg daily in CYP2D6 EMs when used with strong CYP3A4 inhibitors. Use of strong CYP3A4 inhibitors is contraindicated in CYP2D6 IMs, PMs, or in CYP2D6 EMs who are also taking strong or moderate CYP2D6 inhibitors. Risk D: Consider therapy modification

Enfortumab Vedotin: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Enfortumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor therapy

Entrectinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Entrectinib. Management: Avoid strong CYP3A4 inhibitors if possible. If needed, reduce entrectinib dose to 50 mg on alternating days if starting dose 200 mg; to 50 mg/day if starting dose 300 mg or 400 mg; to 100 mg/day if starting dose 600 mg. Risk D: Consider therapy modification

Eplerenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eplerenone. Risk X: Avoid combination

Erdafitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erdafitinib. Management: Avoid concomitant use of erdafitinib and strong CYP3A4 inhibitors when possible. If combined, monitor closely for erdafitinib adverse reactions and consider dose modifications accordingly. Risk D: Consider therapy modification

Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates). Risk X: Avoid combination

Erlotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erlotinib. Management: Avoid use of this combination when possible. When the combination must be used, monitor the patient closely for the development of erlotinib-associated adverse reactions, and if such severe reactions occur, reduce the erlotinib dose (in 50 mg decrements). Risk D: Consider therapy modification

Erythromycin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erythromycin (Systemic). Management: Consider alternatives to this combination when possible. If combined, monitor for increased erythromycin effects and toxicities, including QTc interval prolongation. Risk D: Consider therapy modification

Estrogen Derivatives: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Estrogen Derivatives. Risk C: Monitor therapy

Eszopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eszopiclone. Management: Limit the eszopiclone dose to 2 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased eszopiclone effects and toxicities (eg, somnolence, drowsiness, CNS depression). Risk D: Consider therapy modification

Etizolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Etizolam. Risk C: Monitor therapy

Etoposide: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Etoposide. Risk C: Monitor therapy

Etoposide Phosphate: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Etoposide Phosphate. Risk C: Monitor therapy

Etravirine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Etravirine. Risk C: Monitor therapy

Everolimus: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Everolimus. Risk X: Avoid combination

Evogliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Evogliptin. Risk C: Monitor therapy

Fedratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fedratinib. Management: Consider alternatives when possible. If used together, decrease fedratinib dose to 200 mg/day. After the inhibitor is stopped, increase fedratinib to 300 mg/day for the first 2 weeks and then to 400 mg/day as tolerated. Risk D: Consider therapy modification

Felodipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Felodipine. Management: Consider using lower felodipine doses when combined with strong CYP3A4 inhibitors. Monitor patients for increased felodipine effects and toxicities (eg, hypotension, edema) when combined. Risk D: Consider therapy modification

FentaNYL: CYP3A4 Inhibitors (Strong) may increase the serum concentration of FentaNYL. Management: Consider fentanyl dose reductions when combined with a strong CYP3A4 inhibitor. Monitor for respiratory depression and sedation. Upon discontinuation of a CYP3A4 inhibitor, consider a fentanyl dose increase; monitor for signs and symptoms of withdrawal. Risk D: Consider therapy modification

Fesoterodine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fesoterodine. Management: Limit fesoterodine doses to 4 mg daily in patients who are also receiving strong CYP3A4 inhibitors. This combination is not recommended in pediatric patients weighing 25 kg up to 35 kg. Risk D: Consider therapy modification

Fexinidazole: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Fexinidazole. Management: Avoid use of fexinidazole and strong CYP3A4 inhibitors when possible. If combined, monitor for reduced fexinidazole efficacy. Risk D: Consider therapy modification

Finerenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Finerenone. Risk X: Avoid combination

Flibanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Flibanserin. Management: Use of flibanserin with strong CYP3A4 inhibitors is contraindicated. If starting flibanserin, start 2 weeks after the last dose of the CYP3A4 inhibitor. If starting a CYP3A4 inhibitor, start 2 days after the last dose of flibanserin. Risk X: Avoid combination

Flunitrazepam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Flunitrazepam. Risk C: Monitor therapy

Fluticasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Nasal). Risk X: Avoid combination

Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Oral Inhalation). Management: Consider alternatives to this combination if possible. Coadministration of fluticasone propionate and strong CYP3A4 inhibitors is not recommended. If combined, monitor patients for systemic corticosteroid adverse effects (eg, adrenal suppression). Risk D: Consider therapy modification

Fluticasone (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Topical). Risk C: Monitor therapy

Fosamprenavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fosamprenavir. Risk C: Monitor therapy

Fosaprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fosaprepitant. Risk X: Avoid combination

Fostamatinib: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fostamatinib. Risk C: Monitor therapy

Futibatinib: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Futibatinib. Risk X: Avoid combination

Galantamine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Galantamine. Risk C: Monitor therapy

Gefitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gefitinib. Risk C: Monitor therapy

Gepirone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gepirone. Risk X: Avoid combination

Gilteritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gilteritinib. Management: Consider alternatives to the use of a strong CYP3A4 inhibitor with gilteritinib. If the combination cannot be avoided, monitor more closely for evidence of gilteritinib toxicities. Risk D: Consider therapy modification

Glasdegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Glasdegib. Management: Consider alternatives to this combination when possible. If the combination must be used, monitor closely for evidence of QT interval prolongation and other adverse reactions to glasdegib. Risk D: Consider therapy modification

Glecaprevir and Pibrentasvir: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Glecaprevir and Pibrentasvir. Risk C: Monitor therapy

GuanFACINE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of GuanFACINE. Management: Reduce the extended-release guanfacine dose 50% when combined with a strong CYP3A4 inhibitor. Monitor for increased guanfacine toxicities when these agents are combined. Risk D: Consider therapy modification

Halofantrine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Halofantrine. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for halofantrine toxicities, including QTc interval prolongation. Risk D: Consider therapy modification

Haloperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Haloperidol. Risk C: Monitor therapy

Hormonal Contraceptives: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Hormonal Contraceptives. Risk C: Monitor therapy

HYDROcodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of HYDROcodone. Risk C: Monitor therapy

Hydrocortisone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Hydrocortisone (Systemic). Risk C: Monitor therapy

Ibrexafungerp: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrexafungerp. Management: Decrease the ibrexafungerp dose to 150 mg every 12 hours for 2 doses in patients receiving strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Ibrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrutinib. Management: Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for 7 days or less), interrupt ibrutinib therapy until the strong CYP3A4 inhibitor is discontinued. Risk X: Avoid combination

Idelalisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Idelalisib. Management: Use alternative therapies that are not strong CYP3A4 inhibitors whenever possible. If unable to use alternative drugs, monitor patients more frequently for idelalisib toxicities. Risk D: Consider therapy modification

Ifosfamide: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. Risk C: Monitor therapy

Iloperidone: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Imatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imatinib. Risk C: Monitor therapy

Imidafenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imidafenacin. Risk C: Monitor therapy

Indinavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Indinavir. Risk C: Monitor therapy

Infigratinib: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Infigratinib. CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Infigratinib. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Infigratinib. Risk X: Avoid combination

Irinotecan Products: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be increased. Management: Avoid administration of strong CYP3A4 inhibitors during and within 1 week prior to irinotecan administration, unless no therapeutic alternatives to these agents exist. If combined, monitor closely for increased irinotecan toxicities. Risk D: Consider therapy modification

Isavuconazonium Sulfate: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Strong) may increase isavuconazole serum concentrations. Risk X: Avoid combination

Isradipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Isradipine. Risk C: Monitor therapy

Istradefylline: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Istradefylline. Management: Limit the maximum istradefylline dose to 20 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased istradefylline effects/toxicities. Risk D: Consider therapy modification

Itraconazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Itraconazole. Risk C: Monitor therapy

Ivabradine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivabradine. Risk X: Avoid combination

Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivacaftor. Management: Ivacaftor dose reductions are required; consult full drug interaction monograph content for age- and weight-specific recommendations. Risk D: Consider therapy modification

Ivosidenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivosidenib. Management: Avoid use of a strong CYP3A4 inhibitor with ivosidenib whenever possible. When combined use is required, reduce the ivosidenib dose to 250 mg once daily and monitor for increased ivosidenib toxicities, including QTc interval prolongation. Risk D: Consider therapy modification

Ixabepilone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ixabepilone. Management: Avoid use of ixabepilone and strong CYP3A4 inhibitors when possible. If combined, reduce the ixabepilone dose to 20 mg/m². The previous ixabepilone dose can be resumed 1 week after discontinuation of the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Ketamine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ketamine. Risk C: Monitor therapy

Ketoconazole (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ketoconazole (Systemic). Risk C: Monitor therapy

Lacidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lacidipine. Risk C: Monitor therapy

Lapatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lapatinib. Management: Avoid use of lapatinib and strong CYP3A4 inhibitors when possible. If combined, a reduced lapatinib dose of 500 mg daily should be considered. The previous lapatinib dose can be resumed 1 week after discontinuation of the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Larotrectinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Larotrectinib. Management: Avoid use of strong CYP3A4 inhibitors with larotrectinib. If this combination cannot be avoided, reduce the larotrectinib dose by 50%. Increase to previous dose after stopping the inhibitor after a period of 3 to 5 times the inhibitor's half-life. Risk D: Consider therapy modification

Lefamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin tablets and strong inhibitors of CYP3A4. Risk X: Avoid combination

Lemborexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lemborexant. Risk X: Avoid combination

Leniolisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Leniolisib. Risk X: Avoid combination

Lercanidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lercanidipine. Risk X: Avoid combination

Leuprolide and Norethindrone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Leuprolide and Norethindrone. Specifically, concentrations of norethindrone may increase. Risk C: Monitor therapy

Levamlodipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levamlodipine. Risk C: Monitor therapy

Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levobupivacaine. Risk C: Monitor therapy

Levoketoconazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levoketoconazole. Risk X: Avoid combination

Levomethadone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levomethadone. Risk C: Monitor therapy

Levomilnacipran: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levomilnacipran. Management: The dose of levomilnacipran should not exceed 80 mg once daily when used with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Lidocaine (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lidocaine (Systemic). Risk C: Monitor therapy

Lomitapide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lomitapide. Risk X: Avoid combination

Lonafarnib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lonafarnib. Risk X: Avoid combination

Lopinavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lopinavir. Risk C: Monitor therapy

Lorlatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lorlatinib. Management: Avoid use of lorlatinib with strong CYP3A4 inhibitors. If the combination cannot be avoided, reduce the lorlatinib dose from 100 mg once daily to 75 mg once daily, or from 75 mg once daily to 50 mg once daily. Risk D: Consider therapy modification

Lovastatin: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Lovastatin. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lovastatin. Risk X: Avoid combination

Lumateperone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumateperone. Management: Limit the lumateperone dose to 10.5 mg once daily when used with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Lurasidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurasidone. Risk X: Avoid combination

Lurbinectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurbinectedin. Management: Avoid concomitant use of lurbinectedin and strong CYP3A4 inhibitors. If coadministration with a strong CYP3A4 inhibitor cannot be avoided, reduce the lurbinectedin dose by 50%. Risk D: Consider therapy modification

Macitentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Macitentan. Risk X: Avoid combination

Manidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Manidipine. Management: Consider avoiding concomitant use of manidipine and strong CYP3A4 inhibitors. If combined, monitor closely for increased manidipine effects and toxicities. Manidipine dose reductions may be required. Risk D: Consider therapy modification

Maraviroc: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Maraviroc. Management: Reduce maraviroc to 150mg twice/day in adult and pediatrics weighing 40kg or more. See full interaction monograph for dose adjustments in pediatrics weighing 10 to less than 40kg. Do not use if CrCl less than 30mL/min or in those weighing less than 10 kg. Risk D: Consider therapy modification

Mavacamten: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mavacamten. Risk X: Avoid combination

Mefloquine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mefloquine. Risk C: Monitor therapy

Meperidine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Meperidine. Risk C: Monitor therapy

MetFORMIN: MATE1/2-K Inhibitors may increase the serum concentration of MetFORMIN. Risk C: Monitor therapy

Methadone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Methadone. Management: If coadministration with strong CYP3A4 inhibitors is necessary, consider methadone dose reductions until stable effects are achieved. Monitor patients closely for respiratory depression and sedation. Risk D: Consider therapy modification

MethylPREDNISolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MethylPREDNISolone. Risk C: Monitor therapy

Midazolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Midazolam. Management: Avoid use of nasal midazolam and strong CYP3A4 inhibitors whenever possible, and consider alternatives to use with other routes of midazolam (oral, IV, IM). If combined, consider lower midazolam doses and monitor for increased midazolam toxicities. Risk D: Consider therapy modification

Midostaurin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Midostaurin. Management: Seek alternatives to the concomitant use of midostaurin and strong CYP3A4 inhibitors if possible. If concomitant use cannot be avoided, monitor patients for increased risk of adverse reactions. Risk D: Consider therapy modification

MiFEPRIStone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MiFEPRIStone. Management: For treatment of hyperglycemia in Cushing's syndrome, start mifepristone at 300 mg/day, may titrate to a maximum of 900 mg/day. If starting a strong CYP3A4 inhibitor and taking > 300 mg/day mifepristone, decrease the mifepristone dose by 300 mg/day. Risk D: Consider therapy modification

Mirodenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirodenafil. Management: Consider using a lower dose of mirodenafil when used with strong CYP3A4 inhibitors. Monitor for increased mirodenafil effects/toxicities with the use of this combination. Risk D: Consider therapy modification

Mirtazapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirtazapine. Risk C: Monitor therapy

Mirvetuximab Soravtansine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirvetuximab Soravtansine. Risk C: Monitor therapy

Mitapivat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mitapivat. Risk X: Avoid combination

Mobocertinib: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Mobocertinib. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mobocertinib. Risk X: Avoid combination

Mometasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mometasone (Nasal). Risk C: Monitor therapy

Mometasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mometasone (Oral Inhalation). Risk C: Monitor therapy

Mometasone (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mometasone (Topical). Risk C: Monitor therapy

Morphine (Systemic): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Morphine (Systemic). Risk C: Monitor therapy

Nadolol: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Nadolol. Risk C: Monitor therapy

Naldemedine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naldemedine. Risk C: Monitor therapy

Naldemedine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Naldemedine. Risk C: Monitor therapy

Nalfurafine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nalfurafine. Risk C: Monitor therapy

Naloxegol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naloxegol. Risk X: Avoid combination

Nelfinavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nelfinavir. Risk C: Monitor therapy

Neratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Neratinib. Risk X: Avoid combination

NiCARdipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NiCARdipine. Risk C: Monitor therapy

NIFEdipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NIFEdipine. Management: Consider alternatives to this combination when possible. If combined, initiate nifedipine at the lowest dose available and monitor patients closely for increased nifedipine effects and toxicities (eg, hypotension, edema). Risk D: Consider therapy modification

Nilotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nilotinib. Management: Avoid if possible. If combination needed, decrease nilotinib to 300 mg once/day for patients with resistant or intolerant Ph+ CML or to 200 mg once/day for patients with newly diagnosed Ph+ CML in chronic phase. Risk D: Consider therapy modification

Nilvadipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nilvadipine. Risk C: Monitor therapy

NiMODipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NiMODipine. Risk X: Avoid combination

Nintedanib: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Nintedanib. Risk C: Monitor therapy

Nirmatrelvir and Ritonavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nirmatrelvir and Ritonavir. Risk C: Monitor therapy

Nirogacestat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nirogacestat. Risk X: Avoid combination

Nisoldipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nisoldipine. Risk X: Avoid combination

Nitrendipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nitrendipine. Risk C: Monitor therapy

Olaparib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Olaparib. Management: Avoid use of strong CYP3A4 inhibitors with olaparib, if possible. If such concurrent use cannot be avoided, the dose of olaparib tablets should be reduced to 100 mg twice daily and the dose of olaparib capsules should be reduced to 150 mg twice daily. Risk D: Consider therapy modification

Oliceridine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Oliceridine. Risk C: Monitor therapy

Olmutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Olmutinib. Risk C: Monitor therapy

Omaveloxolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Omaveloxolone. Management: Avoid this combination if possible. If coadministration is required, decrease the omaveloxolone dose to 50 mg daily and monitor closely for adverse reactions. Discontinue coadministration if adverse reactions occur. Risk D: Consider therapy modification

Orelabrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Orelabrutinib. Risk X: Avoid combination

Osilodrostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Osilodrostat. Management: Reduce osilodrostat dose by 50% during coadministration with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Ospemifene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ospemifene. Risk C: Monitor therapy

OxyBUTYnin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of OxyBUTYnin. Risk C: Monitor therapy

OxyCODONE: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of OxyCODONE. CYP3A4 Inhibitors (Strong) may increase the serum concentration of OxyCODONE. Serum concentrations of the active metabolite oxymorphone may also be increased. Risk C: Monitor therapy

PACLitaxel (Conventional): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PACLitaxel (Conventional). Risk C: Monitor therapy

PACLitaxel (Protein Bound): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor therapy

Pacritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pacritinib. Risk X: Avoid combination

Palbociclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Palbociclib. Management: Avoid concurrent use of strong CYP3A4 inhibitors with palbociclib when possible. If the use of a strong CYP3A4 inhibitor cannot be avoided, decrease the palbociclib dose to 75 mg/day. Risk D: Consider therapy modification

Palovarotene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Palovarotene. Risk X: Avoid combination

Panobinostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Panobinostat. Management: Reduce the panobinostat dose to 10 mg when it must be used with a strong CYP3A4 inhibitor. Monitor patient response to therapy closely for evidence of more severe adverse effects related to panobinostat therapy. Risk D: Consider therapy modification

Parecoxib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Parecoxib. Specifically, serum concentrations of the active moiety valdecoxib may be increased. Risk C: Monitor therapy

Paricalcitol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Paricalcitol. Risk C: Monitor therapy

PAZOPanib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of PAZOPanib. Risk X: Avoid combination

Pemigatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pemigatinib. Management: If combined use cannot be avoided, reduce the pemigatinib dose from 13.5 mg daily to 9 mg daily, or from 9 mg daily to 4.5 mg daily. Resume prior pemigatinib dose after stopping the strong inhibitor once 3 half-lives of the inhibitor has passed. Risk D: Consider therapy modification

Pexidartinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pexidartinib. Management: If combined use cannot be avoided, pexidartinib dose should be reduced. For the 125 mg capsules: reduce pexidartinib doses of 500 mg or 375 mg daily to 125 mg twice daily. Reduce pexidartinib 250 mg daily to 125 mg once daily. Risk D: Consider therapy modification

Pimavanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimavanserin. Management: Decrease the pimavanserin dose to 10 mg daily when combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Pimecrolimus: CYP3A4 Inhibitors (Strong) may decrease the metabolism of Pimecrolimus. Risk C: Monitor therapy

Pimozide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimozide. Risk X: Avoid combination

Piperaquine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Piperaquine. Risk C: Monitor therapy

Pirtobrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pirtobrutinib. Management: Avoid concomitant use when possible. If combined, reduce the pirtobrutinib dose by 50 mg. If current dose is 50 mg, interrupt pirtobrutinib treatment during strong CYP3A4 inhibitor use. Risk D: Consider therapy modification

Polatuzumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be increased. Risk C: Monitor therapy

PONATinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PONATinib. Management: Avoid concomitant use if possible. If combined, reduce ponatinib dose as follows: If taking 45 mg, reduce to 30 mg; if taking 30 mg, reduce to 15 mg; if taking 15 mg, reduce to 10 mg. If taking 10 mg, avoid concomitant use with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Pralsetinib: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Pralsetinib. Management: Avoid concomitant use if possible. If combined, reduce the pralsetinib dose. If taking 400 mg or 300 mg once daily, reduce to 200 mg once daily. If taking 200 mg once daily, reduce to 100 mg once daily. Risk D: Consider therapy modification

Prazepam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Prazepam. Risk C: Monitor therapy

Praziquantel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Praziquantel. Risk C: Monitor therapy

PrednisoLONE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PrednisoLONE (Systemic). Risk C: Monitor therapy

PredniSONE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PredniSONE. Risk C: Monitor therapy

Propafenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Propafenone. Risk C: Monitor therapy

QUEtiapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of QUEtiapine. Management: In quetiapine treated patients, reduce quetiapine to one-sixth of original dose after starting a strong CYP3A4 inhibitor. In those on strong CYP3A4 inhibitors, start quetiapine at lowest dose and up-titrate as needed. Risk D: Consider therapy modification

QuiNIDine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of QuiNIDine. Risk C: Monitor therapy

Quinidine (Non-Therapeutic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Quinidine (Non-Therapeutic). Risk C: Monitor therapy

QuiNINE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of QuiNINE. Risk C: Monitor therapy

Quizartinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Quizartinib. Management: If combination is necessary, reduce quizartinib dose as follows: from 53 mg daily to 26.5 mg daily; from 35.4 mg daily to 17.7 mg daily; from 26.5 mg daily to 17.7 mg daily. If taking 17.7 mg daily avoid quizartinib while on the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Radotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Radotinib. Risk X: Avoid combination

Ramelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ramelteon. Risk C: Monitor therapy

Ranolazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ranolazine. Risk X: Avoid combination

Reboxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Reboxetine. Risk C: Monitor therapy

Red Yeast Rice: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Red Yeast Rice. Specifically, concentrations of lovastatin and related compounds found in Red Yeast Rice may be increased. Risk X: Avoid combination

Regorafenib: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Regorafenib. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Regorafenib. Risk X: Avoid combination

Relugolix: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Relugolix. Management: Avoid coadministration of relugolix with oral P-gp inhibitors whenever possible. If combined, take relugolix at least 6 hours prior to the P-gp inhibitor and monitor patients more frequently for adverse reactions. Risk D: Consider therapy modification

Relugolix, Estradiol, and Norethindrone: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Relugolix, Estradiol, and Norethindrone. Management: Avoid use of relugolix/estradiol/norethindrone with P-glycoprotein (P-gp) inhibitors. If concomitant use is unavoidable, relugolix/estradiol/norethindrone should be administered at least 6 hours before the P-gp inhibitor. Risk D: Consider therapy modification

Repaglinide: Tucatinib may increase the serum concentration of Repaglinide. Risk C: Monitor therapy

Repotrectinib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Repotrectinib. Risk X: Avoid combination

Retapamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Retapamulin. Management: The use of retapamulin with strong CYP3A4 inhibitors is not recommended in patients less than 2 years old. No action is required in other populations. Risk C: Monitor therapy

Ribociclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ribociclib. Management: Avoid use of ribociclib with strong CYP3A4 inhibitors when possible; if combined use cannot be avoided, reduce ribociclib dose to 400 mg once daily. Risk D: Consider therapy modification

Rifabutin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rifabutin. Risk C: Monitor therapy

RifAXIMin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of RifAXIMin. Risk C: Monitor therapy

Rilpivirine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rilpivirine. Risk C: Monitor therapy

Rimegepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rimegepant. Risk X: Avoid combination

Riociguat: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Riociguat. Management: Consider a riociguat starting dose of 0.5 mg 3 times a day when initiating riociguat in patients receiving strong CYP3A4 and P-gp inhibitors. Monitor for hypotension when these agents are combined and reduce the riociguat dose as needed. Risk D: Consider therapy modification

Ripretinib: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ripretinib. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ripretinib. Risk C: Monitor therapy

RisperiDONE: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of RisperiDONE. Risk C: Monitor therapy

Ritonavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ritonavir. Risk C: Monitor therapy

Rivaroxaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Rivaroxaban. Risk X: Avoid combination

Roflumilast-Containing Products: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Roflumilast-Containing Products. Risk C: Monitor therapy

RomiDEPsin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of RomiDEPsin. Risk C: Monitor therapy

Rupatadine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rupatadine. Risk X: Avoid combination

Ruxolitinib (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib (Systemic). Management: This combination should be avoided under some circumstances; dose adjustments may be required in some circumstances and depend on the indication for ruxolitinib. See monograph for details. Risk D: Consider therapy modification

Ruxolitinib (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib (Topical). Risk X: Avoid combination

Salmeterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Salmeterol. Risk X: Avoid combination

Saquinavir: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Saquinavir. Risk C: Monitor therapy

Saquinavir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Saquinavir. Risk C: Monitor therapy

SAXagliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SAXagliptin. Management: Limit the saxagliptin dose to 2.5 mg daily when combined with strong CYP3A4 inhibitors. When using the saxagliptin combination products saxagliptin/dapagliflozin or saxagliptin/dapagliflozin/metformin, avoid use with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Selpercatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Selpercatinib. Management: Avoid combination if possible. If use is necessary, reduce selpercatinib dose as follows: from 120 mg twice/day to 40 mg twice/day, or from 160 mg twice/day to 80 mg twice/day. Risk D: Consider therapy modification

Selumetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Selumetinib. Management: Avoid concomitant use when possible. If combined, selumetinib dose reductions are recommended and vary based on body surface area and selumetinib dose. For details, see the full drug interaction monograph or selumetinib prescribing information. Risk D: Consider therapy modification

Sertindole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sertindole. Risk X: Avoid combination

Sibutramine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Sibutramine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sibutramine. Risk C: Monitor therapy

Sildenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sildenafil. Management: Use of sildenafil for pulmonary arterial hypertension (PAH) should be avoided with strong CYP3A4 inhibitors. When used for erectile dysfunction, consider using a lower starting dose of 25 mg and monitor patients for sildenafil toxicities. Risk D: Consider therapy modification

Silodosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Silodosin. Risk X: Avoid combination

Simeprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simeprevir. Risk X: Avoid combination

Simvastatin: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Simvastatin. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simvastatin. Risk X: Avoid combination

Sirolimus (Conventional): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sirolimus (Conventional). Management: Avoid concurrent use of sirolimus with strong CYP3A4 inhibitors when possible and alternative agents with lesser interaction potential with sirolimus should be considered. Concomitant use of sirolimus and voriconazole or posaconazole is contraindicated. Risk D: Consider therapy modification

Sirolimus (Conventional): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Sirolimus (Conventional). Management: Avoid concurrent use of sirolimus with P-glycoprotein (P-gp) inhibitors when possible and alternative agents with lesser interaction potential with sirolimus should be considered. Monitor for increased sirolimus concentrations/toxicity if combined. Risk D: Consider therapy modification

Sirolimus (Protein Bound): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sirolimus (Protein Bound). Risk X: Avoid combination

Sirolimus (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sirolimus (Topical). Risk C: Monitor therapy

Solifenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Solifenacin. Management: Limit adult solifenacin doses to 5 mg daily and limit doses in pediatric patients to the recommended weight-based starting dose (and do not increase the dose) when combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Sonidegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sonidegib. Risk X: Avoid combination

Sparsentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sparsentan. Risk X: Avoid combination

SUFentanil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SUFentanil. Management: If a strong CYP3A4 inhibitor is initiated in a patient on sufentanil, consider a sufentanil dose reduction and monitor for increased sufentanil effects and toxicities (eg, respiratory depression). Risk D: Consider therapy modification

SUNItinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SUNItinib. Management: Avoid when possible. If combined, decrease sunitinib dose to a minimum of 37.5 mg daily when treating GIST or RCC. Decrease sunitinib dose to a minimum of 25 mg daily when treating PNET. Monitor patients for both reduced efficacy and increased toxicities. Risk D: Consider therapy modification

Suvorexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Suvorexant. Risk X: Avoid combination

Tacrolimus (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tacrolimus (Systemic). Management: Reduce tacrolimus dose to one-third of the original dose if starting posaconazole or voriconazole. Coadministration with nelfinavir is not generally recommended. Tacrolimus dose reductions or prolongation of dosing interval will likely be required. Risk D: Consider therapy modification

Tacrolimus (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tacrolimus (Topical). Risk C: Monitor therapy

Tadalafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tadalafil. Management: Avoid this combination in patients taking tadalafil for pulmonary arterial hypertension. In patients taking tadalafil for ED or BPH, max tadalafil dose is 2.5 mg if taking daily or 10 mg no more frequently than every 72 hours if used as needed. Risk D: Consider therapy modification

Talazoparib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Talazoparib. Risk C: Monitor therapy

Tamsulosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tamsulosin. Risk X: Avoid combination

Tasimelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tasimelteon. Risk C: Monitor therapy

Tazemetostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tazemetostat. Risk X: Avoid combination

Tegaserod (Withdrawn from US Market): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Tegaserod (Withdrawn from US Market). Risk C: Monitor therapy

Temsirolimus: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Temsirolimus. Specifically, concentrations of sirolimus may be increased. Management: Avoid concomitant use of temsirolimus and strong CYP3A4 inhibitors. If coadministration is unavoidable, decrease temsirolimus dose to 12.5 mg per week. Resume previous temsirolimus dose 1 week after discontinuation of the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Teniposide: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Teniposide. Risk C: Monitor therapy

Tenofovir Disoproxil Fumarate: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Tenofovir Disoproxil Fumarate. Risk C: Monitor therapy

Terfenadine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Terfenadine. Risk X: Avoid combination

Tetrahydrocannabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol. Risk C: Monitor therapy

Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol and Cannabidiol. Risk C: Monitor therapy

Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tezacaftor and Ivacaftor. Management: If combined with strong CYP3A4 inhibitors, tezacaftor/ivacaftor should be administered in the morning, twice a week, approximately 3 to 4 days apart. Tezacaftor/ivacaftor dose depends on age and weight; see full Lexi-Interact monograph for details. Risk D: Consider therapy modification

Thiotepa: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Thiotepa. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Thiotepa. Management: Avoid coadministration of thiotepa and strong CYP3A4 inhibitors. If concomitant use cannot be avoided, monitor for thiotepa adverse effects and decreased efficacy. Risk D: Consider therapy modification

Ticagrelor: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ticagrelor. Risk X: Avoid combination

Tisotumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tisotumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tofacitinib. Management: Tofacitinib dose reductions are recommended when combined with strong CYP3A4 inhibitors. Recommended dose adjustments vary by tofacitinib formulation and therapeutic indication. See full Lexi Interact monograph for details. Risk D: Consider therapy modification

Tolterodine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolterodine. Management: The maximum recommended dose of tolterodine is 2 mg per day (1 mg twice daily for immediate-release tablets or 2 mg daily for extended-release capsules) when used together with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Tolvaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolvaptan. Risk X: Avoid combination

Topotecan: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Topotecan. Risk X: Avoid combination

Toremifene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Toremifene. Management: Use of toremifene with strong CYP3A4 inhibitors should be avoided if possible. If coadministration is necessary, monitor for increased toremifene toxicities, including QTc interval prolongation. Risk D: Consider therapy modification

Trabectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Trabectedin. Risk X: Avoid combination

TraMADol: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of TraMADol. CYP3A4 Inhibitors (Strong) may increase the serum concentration of TraMADol. Risk C: Monitor therapy

TraZODone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of TraZODone. Management: Consider the use of a lower trazodone dose and monitor for increased trazodone effects (eg, sedation, QTc prolongation) if combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Tretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tretinoin (Systemic). Risk C: Monitor therapy

Triamcinolone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triamcinolone (Nasal). Risk C: Monitor therapy

Triamcinolone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triamcinolone (Ophthalmic). Risk C: Monitor therapy

Triamcinolone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triamcinolone (Systemic). Management: Consider alternatives to this combination when possible. If combined, monitor for increased corticosteroid adverse effects during coadministration of triamcinolone and strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Triamcinolone (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triamcinolone (Topical). Risk C: Monitor therapy

Triazolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triazolam. Risk X: Avoid combination

Ubrogepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ubrogepant. Risk X: Avoid combination

Udenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Udenafil. Risk X: Avoid combination

Ulipristal: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ulipristal. Risk C: Monitor therapy

Upadacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Upadacitinib. Management: Upadacitinib dose adjustments are needed when combined with strong CYP3A4 inhibitors. Specific adjustments vary based on upadacitinib indication. See full interact monograph for details. Risk D: Consider therapy modification

Valbenazine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Valbenazine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Valbenazine. Management: Reduce the valbenazine dose to 40 mg daily when combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Vamorolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vamorolone. Management: Reduce the vamorolone dose to 4 mg/kg daily, with a maximum dose of 200 mg daily for patients weighing over 50 kg, when combined with strong CYP3A4 inhibitors. Risk D: Consider therapy modification

Vardenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vardenafil. Management: Limit Levitra (vardenafil) dose to a single 2.5 mg dose within a 24-hour period if combined with strong CYP3A4 inhibitors. Avoid concomitant use of Staxyn (vardenafil) and strong CYP3A4 inhibitors. Combined use is contraindicated outside of the US. Risk D: Consider therapy modification

Vemurafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vemurafenib. Management: Avoid concurrent use of vemurafenib with strong CYP3A4 inhibitors when possible. If concomitant use is unavoidable, consider a vemurafenib dose reduction if clinically indicated. Risk D: Consider therapy modification

Venetoclax: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Venetoclax. Management: Coadministration is contraindicated during venetoclax initiation and ramp-up in CLL/SLL patients. Reduced venetoclax doses are required during ramp-up for patients with AML, and all maintenance therapy. See full Lexi Interact monograph for details. Risk D: Consider therapy modification

Verapamil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Verapamil. Risk C: Monitor therapy

Vilanterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilanterol. Risk C: Monitor therapy

Vilazodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilazodone. Management: Limit the maximum vilazodone dose to 20 mg daily in patients receiving strong CYP3A4 inhibitors. The original vilazodone dose can be resumed following discontinuation of the strong CYP3A4 inhibitor. Risk D: Consider therapy modification

VinBLAStine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinBLAStine. Risk C: Monitor therapy

VinCRIStine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine. Management: Seek alternatives to this combination when possible. If combined, monitor closely for vincristine toxicities (eg, neurotoxicity, gastrointestinal toxicity, myelosuppression). Risk D: Consider therapy modification

VinCRIStine (Liposomal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine (Liposomal). Risk X: Avoid combination

Vindesine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vindesine. Risk C: Monitor therapy

Vinflunine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Vinflunine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinflunine. Risk X: Avoid combination

Vinorelbine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinorelbine. Risk C: Monitor therapy

Voclosporin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Voclosporin. Risk X: Avoid combination

Vorapaxar: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vorapaxar. Risk X: Avoid combination

Voriconazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Voriconazole. Risk C: Monitor therapy

Zanubrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zanubrutinib. Management: Decrease the zanubrutinib dose to 80 mg once daily during coadministration with a strong CYP3A4 inhibitor. Further dose adjustments may be required for zanubrutinib toxicities, refer to prescribing information for details. Risk D: Consider therapy modification

Ziprasidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ziprasidone. Risk C: Monitor therapy

Zolpidem: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zolpidem. Risk C: Monitor therapy

Zopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zopiclone. Management: If coadministered with strong CYP3A4 inhibitors, initiate zopiclone at 3.75 mg in adults, with a maximum dose of 5 mg. Monitor for zopiclone toxicity (eg, drowsiness, confusion, lethargy, ataxia, respiratory depression). Risk D: Consider therapy modification

Zuranolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zuranolone. Management: Reduce the zuranolone dose to 30 mg once daily when used concomitantly with a strong CYP3A4 inhibitor. Risk D: Consider therapy modification

Reproductive Considerations

Evaluate pregnancy status prior to use in patients who could become pregnant.

Patients who could become pregnant should use effective contraception during tucatinib therapy and for 1 week after the last tucatinib dose. Patients with partners who could become pregnant should use effective contraception during tucatinib therapy and for 1 week after the last tucatinib dose.

Tucatinib is used in combination with trastuzumab and capecitabine. Also refer to Trastuzumab and Capecitabine monographs for additional information.

Pregnancy Considerations

Based on the mechanism of action and data from animal reproduction studies, in utero exposure to tucatinib may cause fetal harm.

Tucatinib is used in combination with trastuzumab and capecitabine. Also refer to Trastuzumab and Capecitabine monographs for additional information.

Breastfeeding Considerations

It is not known if tucatinib is present in breast milk.

Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended by the manufacturer during tucatinib treatment or for 1 week after the last tucatinib dose.

Tucatinib is used in combination with trastuzumab and capecitabine. Also refer to Trastuzumab and Capecitabine monographs for additional information.

Monitoring Parameters

HER2 positivity (breast cancer and colorectal cancer); RAS wild-type status (colorectal cancer). Monitor ALT, AST, and bilirubin (prior to tucatinib initiation, every 3 weeks during treatment, and as clinically indicated); kidney function (prior to treatment initiation) and as clinically necessary. Evaluate pregnancy status prior to treatment initiation (in patients who could become pregnant). Monitor for signs/symptoms of diarrhea. Monitor adherence.

The American Society of Clinical Oncology hepatitis B virus (HBV) screening and management provisional clinical opinion (ASCO [Hwang 2020]) recommends HBV screening with hepatitis B surface antigen, hepatitis B core antibody, total Ig or IgG, and antibody to hepatitis B surface antigen prior to beginning (or at the beginning of) systemic anticancer therapy; do not delay treatment for screening/results. Detection of chronic or past HBV infection requires a risk assessment to determine antiviral prophylaxis requirements, monitoring, and follow-up.

Cardiovascular monitoring: Comprehensive assessment prior to treatment including a history and physical examination, screening for cardiovascular disease risk factors such as hypertension, diabetes, dyslipidemia, obesity, and smoking (ASCO [Armenian 2017]; ESC [Lyon 2022]).

Mechanism of Action

Tucatinib is a tyrosine kinase inhibitor that is highly selective for the human epidermal growth factor receptor 2 (HER2) kinase domain, with minimal inhibition of epidermal growth factor receptor (Murthy 2020). Tucatinib inhibits HER2 and HER3 phosphorylation, resulting in downstream inhibition of MAPK and AKT signaling and cell proliferation; tucatinib demonstrated antitumor activity in HER2-expressing tumor cells and inhibited growth of HER2-expressing tumors. The combination of tucatinib plus trastuzumab exhibited increased antitumor activity compared to either medication alone.

Pharmacokinetics (Adult Data Unless Noted)

Distribution: V_d: 903 L (metastatic breast cancer); 829 L (metastatic colorectal cancer).

Protein binding: 97.1%.

Metabolism: Primarily via CYP2C8, and to a lesser extent via CYP3A.

Half-life elimination: ~12 hours (metastatic breast cancer); ~16 hours (metastatic colorectal cancer).

Time to peak: ~2 hours (range: 1 to 4 hours).

Excretion: Feces: ~86% (16% as unchanged drug); urine: 4.1%.

Clearance: 53 L/hour (metastatic breast cancer); 89 L/hour (metastatic colorectal cancer).

Pharmacokinetics: Additional Considerations (Adult Data Unless Noted)

Hepatic function impairment: Tucatinib AUC_0-∞was increased by 1.6 fold in subjects with severe (Child-Pugh class C) impairment, compared to subjects with normal hepatic function.

خرید پکیج

Tucatinib: Drug information