Version July 2025
HIV-1 infection, treatment: Note: Must be administered with concomitant atazanavir or darunavir and other antiretroviral drugs. Do not use cobicistat and atazanavir or darunavir with abacavir and lamivudine in patients with a pre-antiretroviral therapy HIV RNA ≥100,000 copies/mL (Ref).
Treatment naive or experienced: Oral: 150 mg once daily with concomitant atazanavir.
Treatment naive or experienced with no darunavir resistance-associated substitutions: Oral: 150 mg once daily with concomitant darunavir.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
When not used with concomitant tenofovir disoproxil fumarate: No dosage adjustment necessary.
When used with concomitant tenofovir disoproxil fumarate:
CrCl ≥70 mL/minute: No dosage adjustment necessary.
CrCl <70 mL/minute: Use is not recommended.
Mild to moderate hepatic impairment (Child-Pugh class A or B): No dosage adjustment necessary.
Severe hepatic impairment (Child-Pugh class C): There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
(For additional information see "Cobicistat: Pediatric drug information")
HIV-1 infection, treatment: Note: Cobicistat is a pharmacokinetic enhancer only and lacks antiretroviral (ARV) activity. Use in combination with ARV agents. It is not interchangeable with ritonavir (Ref). Gene mutation and ARV resistance patterns should be evaluated (refer to https://www.iasusa.org/ for more information) when necessary. In clinical trials, the youngest patients were 12 years of age.
Coadministered with atazanavir 300 mg once daily: Treatment-naive or treatment-experienced: Children and Adolescents ≥35 kg: Oral: 150 mg once daily.
Coadministered with darunavir 800 mg once daily: Treatment-naive or treatment-experienced with no darunavir resistance-associated substitutions: Children and Adolescents ≥40 kg: Oral: 150 mg once daily.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Children and Adolescents (≥35 kg [with atazanavir] or ≥40 kg [with darunavir]): Recommendations vary based on additional antiretroviral therapy:
Without concomitant tenofovir disoproxil fumarate: No dosage adjustment necessary.
With concomitant tenofovir disoproxil fumarate:
CrCl ≥70 mL/minute: No dosage adjustment necessary.
CrCl <70 mL/minute: Use is not recommended.
Children and Adolescents (≥35 kg [with atazanavir] or ≥40 kg [with darunavir]):
Mild to moderate hepatic impairment: No dosage adjustment necessary.
Severe hepatic impairment: There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reactions reported in adults on combination therapy.
>10%: Hepatic: Hyperbilirubinemia (grades 3/4: 73%)
1% to 10%:
Cardiovascular: Increased serum creatine kinase (grades 3/4: 8%)
Dermatologic: Skin rash (5%)
Endocrine & metabolic: Hyperglycemia (grades 3/4: 2%)
Gastrointestinal: Diarrhea (2%), increased serum amylase (grades 3/4: 4%), increased serum lipase (grades 3/4: 7%), nausea (2%), upper abdominal pain (<2%), vomiting (<2%)
Genitourinary: Glycosuria (grades 3/4: 3%), hematuria (grades 3/4: 6%)
Hematologic & oncologic: Decreased neutrophils (grades 3/4: 3%)
Hepatic: Increased gamma-glutamyl transferase (grades 3/4: 4%), increased serum alanine aminotransferase (grades 3/4: 6%), increased serum aspartate aminotransferase (grades 3/4: 4%), jaundice (6%)
Nervous system: Abnormal dreams (<2%), depression (<2%), fatigue (<2%), headache (2%), insomnia (<2%)
Neuromuscular & skeletal: Rhabdomyolysis (<2%)
Ophthalmic: Scleral icterus (4%)
Renal: Fanconi syndrome (<2%), nephrolithiasis (<2%), proximal tubular nephropathy (2%), renal disease (<2%)
Frequency not defined:
Endocrine & metabolic: Increased HDL cholesterol, increased LDL cholesterol, increased serum cholesterol, increased serum triglycerides
Renal: Decreased creatinine clearance, increased serum creatinine
Concomitant use of cobicistat and atazanavir or darunavir with alfuzosin, carbamazepine, colchicine (in patients with renal and/or hepatic impairment), dronedarone, ergot derivatives (eg, dihydroergotamine, ergotamine, methylergonovine), lomitapide, lovastatin, lurasidone, midazolam (oral), phenobarbital, phenytoin, pimozide, ranolazine, rifampin, sildenafil (when used for pulmonary arterial hypertension), simvastatin, St. John wort, triazolam; concomitant use of cobicistat and atazanavir with drospirenone/ethinyl estradiol, indinavir, irinotecan, or nevirapine.
Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Canadian labeling: Additional contraindications (not in US labeling): Apixaban, astemizole (not available in Canada); elbasvir/grazoprevir, ergonovine, rivaroxaban, salmeterol; terfenadine (not available in Canada)
Concerns related to adverse effects:
• Renal toxicity: When used with concomitant tenofovir disoproxil fumarate, may cause renal toxicity (acute renal failure and/or Fanconi syndrome); avoid use with concurrent or recent nephrotoxic therapy. In patients receiving concomitant tenofovir disoproxil fumarate, assess creatinine clearance, urine glucose, and urine protein prior to and periodically during treatment; assess serum phosphorus in patients with or at risk for renal impairment. Do not initiate therapy in combination with tenofovir disoproxil fumarate in patients with CrCl <70 mL/minute.
Concurrent drug therapy issues:
• Appropriate use: Use with HIV-1 protease inhibitors other than atazanavir or darunavir (once-daily dosage regimen) is not recommended; use with more than one antiretroviral that requires pharmacokinetic enhancement (eg, two protease inhibitors or elvitegravir in combination with a protease inhibitor); darunavir 600 mg twice daily; darunavir in combination with efavirenz, etravirine, or nevirapine; atazanavir in combination with etravirine; or atazanavir in combination with efavirenz in treatment-experienced patients is not recommended.
• Concurrent therapy: Avoid concurrent use with other cobicistat-containing products or ritonavir-containing products.
• Drug-drug interactions: Complex or unknown mechanisms of drug interactions preclude extrapolation of ritonavir drug interactions to certain cobicistat interactions. Cobicistat and ritonavir when administered with either atazanavir or darunavir may result in different drug interactions when used with concomitant medications. Consult drug interactions database and contraindications section for more detailed information.
Other warning/precautions:
• False elevations in serum creatinine: May inhibit tubular secretion of creatinine without affecting actual renal glomerular function; use caution when interpreting serum creatinine values in patients with medical conditions or receiving drugs needing to be monitored with estimated creatinine clearance (CrCl). Patients who experience a confirmed increase in serum creatinine >0.4 mg/dL from baseline should have renal function monitored closely. Assess estimated CrCl prior to initiating therapy; consider alternative medications that do not require dosage adjustments in patients with renal impairment.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral:
Tybost: 150 mg [contains fd&c yellow #6(sunset yellow)alumin lake]
No
Tablets (Tybost Oral)
150 mg (per each): $12.59
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.
Oral: Administer with food and at the same time as other coadministered antiretroviral agents.
Oral: Administer with food and at the same time as atazanavir or darunavir.
HIV-1 infection, treatment: Treatment of HIV-1 infection in adults to increase systemic exposure of atazanavir or darunavir (once-daily dosing regimen) in combination with other antiretroviral agents; treatment of HIV-1 infection to increase systemic exposure of atazanavir or darunavir (once-daily regimen) in pediatric patients weighing ≥35 kg or ≥40 kg, respectively, in combination with other antiretroviral agents. Note: Although not included in the FDA prescribing information for cobicistat as a single agent, cobicistat is also FDA approved for use with elvitegravir, as part of fixed-dose combination products.
Limitations of use: Cobicistat is not interchangeable with ritonavir and is not recommended to increase systemic exposure of darunavir 600 mg twice daily, fosamprenavir, saquinavir, or tipranavir due to lack of exposure data.
Cobicistat may be confused with Cotellic
Substrate of CYP3A4 (Major with inducers), CYP3A4 (Minor with inhibitors); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits BCRP, CYP2D6 (Weak), CYP3A4 (Strong), OATP1B1/1B3, P-glycoprotein;
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 drug interactions program by clicking on the “Launch drug interactions program” link above.
Abemaciclib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Acalabrutinib. Risk X: Avoid
Acrivastine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Acrivastine. Risk C: Monitor
Adagrasib: CYP3A4 Inhibitors (Strong) may increase 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 active metabolite exposure 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 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 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 serum concentration of Alfuzosin. Risk X: Avoid
Aliskiren: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Aliskiren. Risk C: Monitor
Alitretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Alosetron. Risk C: Monitor
Alpelisib: BCRP/ABCG2 Inhibitors may increase serum concentration of Alpelisib. Management: Avoid coadministration of BCRP/ABCG2 inhibitors and alpelisib due to the potential for increased alpelisib concentrations and toxicities. If coadministration cannot be avoided, closely monitor for increased alpelisib adverse reactions. Risk D: Consider Therapy Modification
ALPRAZolam: CYP3A4 Inhibitors (Strong) may increase serum concentration of ALPRAZolam. Risk X: Avoid
Amiodarone: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of AmLODIPine. Risk C: Monitor
Apixaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase 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 serum concentration of Aprepitant. Risk X: Avoid
ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure 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
ARIPiprazole: CYP3A4 Inhibitors (Strong) may increase 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
Artemether and Lumefantrine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Artemether and Lumefantrine. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Artemether and Lumefantrine. Specifically, concentrations of dihydroartemisinin (DHA), the active metabolite of artemether may be increased. Risk C: Monitor
Asciminib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Asciminib. Risk C: Monitor
Atazanavir: CYP3A4 Inhibitors (Strong) may increase serum concentration of Atazanavir. Risk C: Monitor
Atidarsagene Autotemcel: Antiretroviral Agents may decrease therapeutic effects of Atidarsagene Autotemcel. Risk X: Avoid
Atogepant: CYP3A4 Inhibitors (Strong) may increase 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
Atogepant: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Atogepant. Management: For episodic migraine, the recommended atogepant dose is 10 mg or 30 mg once daily if given with OATP1B1/1B3 inhibitors. For chronic migraine, the recommended atogepant dose is 30 mg once daily with OATP1B1/1B3 inhibitors. Risk D: Consider Therapy Modification
Atorvastatin: Cobicistat may increase serum concentration of Atorvastatin. Management: Avoid the combined use of atorvastatin with atazanavir/cobicistat. Atorvastatin dose should not exceed 20 mg daily when combined with other cobicistat-containing regimens. Risk D: Consider Therapy Modification
Atrasentan: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Atrasentan. Risk X: Avoid
Avacopan: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Avanafil. Risk X: Avoid
Avapritinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Avapritinib. Risk X: Avoid
Axitinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Barnidipine. Risk X: Avoid
Beclomethasone (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Beclomethasone (Systemic). Risk C: Monitor
Bedaquiline: CYP3A4 Inhibitors (Strong) may increase serum concentration of Bedaquiline. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Bedaquiline. Risk C: Monitor
Benidipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Benidipine. Risk C: Monitor
Benperidol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Benperidol. Risk C: Monitor
Benzhydrocodone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Risk C: Monitor
Beta-Acetyldigoxin: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Beta-Acetyldigoxin. Risk C: Monitor
Betamethasone (Nasal): CYP3A4 Inhibitors (Strong) may increase serum concentration of Betamethasone (Nasal). Risk C: Monitor
Betamethasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Betamethasone (Ophthalmic). Risk C: Monitor
Betamethasone (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Betamethasone (Systemic). Risk C: Monitor
Betamethasone (Topical): CYP3A4 Inhibitors (Strong) may increase serum concentration of Betamethasone (Topical). Risk C: Monitor
Bilastine: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Bilastine. Risk X: Avoid
Blonanserin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Blonanserin. Risk X: Avoid
Bortezomib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Bortezomib. Risk C: Monitor
Bosentan: Cobicistat may increase serum concentration of Bosentan. Bosentan may decrease serum concentration of Cobicistat. Management: Dose adjustment of bosentan and increased monitoring for bosentan toxicities is necessary when these agents are combined. See full drug interaction monograph for details. Risk D: Consider Therapy Modification
Bosutinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Bosutinib. Risk X: Avoid
Brentuximab Vedotin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor
Brexpiprazole: CYP3A4 Inhibitors (Strong) may increase 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 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
Brincidofovir: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Brincidofovir. Management: Consider alternatives to OATP1B/1B3 inhibitors in patients treated with brincidofovir. If coadministration is required, administer OATP1B1/1B3 inhibitors at least 3 hours after brincidofovir and increase monitoring for brincidofovir adverse reactions. Risk D: Consider Therapy Modification
Bromocriptine: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Bromperidol. Risk C: Monitor
Brotizolam: CYP3A4 Inhibitors (Strong) may increase serum concentration of Brotizolam. Risk C: Monitor
Budesonide (Nasal): CYP3A4 Inhibitors (Strong) may increase serum concentration of Budesonide (Nasal). Risk C: Monitor
Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Budesonide (Topical). Risk X: Avoid
Buprenorphine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Buprenorphine. Risk C: Monitor
BusPIRone: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Butorphanol. Risk C: Monitor
Cabazitaxel: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Calcifediol. Risk C: Monitor
Calcitriol (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Calcitriol (Systemic). Risk C: Monitor
Cannabidiol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cannabidiol. Risk C: Monitor
Cannabis: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Risk C: Monitor
Capivasertib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Capmatinib. Risk C: Monitor
CarBAMazepine: Cobicistat may increase serum concentration of CarBAMazepine. CarBAMazepine may decrease serum concentration of Cobicistat. Risk X: Avoid
Cariprazine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cariprazine. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Cariprazine. Specifically, concentrations of didesmethylcariprazine (DDCAR), the primary active metabolite of cariprazine, may increase. Management: Cariprazine dose adjustments are recommended and depend upon whether a patient is initiating a strong CYP3A4 inhibitor or cariprazine, as well as cariprazine indication. See full mono for details. Some non-US labels contraindicate this combination. Risk D: Consider Therapy Modification
Celiprolol: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Celiprolol. Risk C: Monitor
Ceritinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of ChlordiazePOXIDE. Risk C: Monitor
Ciclesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Ciclesonide (Oral Inhalation). Risk C: Monitor
Cilnidipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cilnidipine. Risk C: Monitor
Cilostazol: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Cinacalcet. Risk C: Monitor
Cisapride: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cisapride. Risk X: Avoid
Cladribine: BCRP/ABCG2 Inhibitors may increase serum concentration of Cladribine. Management: Avoid concomitant use of BCRP inhibitors during the 4 to 5 day oral cladribine treatment cycles whenever possible. If combined, consider dose reduction of the BCRP inhibitor and separation in the timing of administration. Risk D: Consider Therapy Modification
Clarithromycin: Cobicistat may decrease active metabolite exposure of Clarithromycin. Cobicistat may increase serum concentration of Clarithromycin. Management: Consider alternative antibiotics. Reduce clarithromycin dose by 50% in patients receiving elvitegravir/cobicistat/emtricitabine/tenofovir with estimated creatinine clearance 50 to 60 mL/min. Closely monitor for clarithromycin toxicity. Risk D: Consider Therapy Modification
Clindamycin (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Clindamycin (Systemic). Risk C: Monitor
ClonazePAM: CYP3A4 Inhibitors (Strong) may increase serum concentration of ClonazePAM. Risk C: Monitor
Clopidogrel: Cobicistat may decrease active metabolite exposure of Clopidogrel. Management: Consider alternatives to this combination when possible, as HIV treatment guidelines recommend that this combination not be coadministered. If coadministered, monitor closely for evidence of diminished antiplatelet response to clopidogrel. Risk D: Consider Therapy Modification
CloZAPine: CYP3A4 Inhibitors (Strong) may increase serum concentration of CloZAPine. Risk C: Monitor
Cobimetinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cobimetinib. Risk X: Avoid
Codeine: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Codeine. Risk C: Monitor
Colchicine: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Conivaptan. Risk X: Avoid
Copanlisib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Cortisone. Risk C: Monitor
Crizotinib: CYP3A4 Inhibitors (Strong) may increase 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 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
CYP3A4 Inducers (Moderate): May decrease serum concentration of Cobicistat. Risk C: Monitor
CYP3A4 Inducers (Strong): May decrease serum concentration of Cobicistat. Management: Consider alternatives to this combination when possible. If combined, monitor for reduced cobicistat efficacy. Risk D: Consider Therapy Modification
CYP3A4 Inhibitors (Strong): May increase serum concentration of Cobicistat. Risk C: Monitor
Cyproterone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Cyproterone. Risk C: Monitor
Dabigatran Etexilate: P-glycoprotein/ABCB1 Inhibitors may increase active metabolite exposure of Dabigatran Etexilate. Risk C: Monitor
Dabrafenib: Cobicistat may increase serum concentration of Dabrafenib. Dabrafenib may decrease serum concentration of Cobicistat. Management: Consider alternatives to the combination of dabrafenib and cobicistat. If such a combination cannot be avoided, monitor closely for evidence of dabrafenib-related adverse effects and reduced cobicistat efficacy. Risk D: Consider Therapy Modification
Daclatasvir: CYP3A4 Inhibitors (Strong) may increase 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
Dapoxetine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Dapoxetine. Risk X: Avoid
Daridorexant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Daridorexant. Risk X: Avoid
Darifenacin: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Darolutamide. Risk C: Monitor
Darunavir: CYP3A4 Inhibitors (Strong) may increase serum concentration of Darunavir. Risk C: Monitor
Dasatinib: CYP3A4 Inhibitors (Strong) may increase 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 active metabolite exposure 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 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 serum concentration of DexAMETHasone (Ophthalmic). Risk C: Monitor
DexAMETHasone (Systemic): Cobicistat may increase serum concentration of DexAMETHasone (Systemic). DexAMETHasone (Systemic) may decrease serum concentration of Cobicistat. Management: Consider an alternative corticosteroid. Monitor patients receiving this combination closely for evidence of diminished response to the antiviral regimen as well as increased dexamethasone effects and toxicities. Risk D: Consider Therapy Modification
DiazePAM: CYP3A4 Inhibitors (Strong) may increase serum concentration of DiazePAM. Risk C: Monitor
Diazoxide Choline: CYP3A4 Inhibitors (Strong) may increase serum concentration of Diazoxide Choline. Risk C: Monitor
Dienogest: CYP3A4 Inhibitors (Strong) may increase serum concentration of Dienogest. Risk C: Monitor
Digitoxin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Digitoxin. Risk C: Monitor
Digitoxin: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Digitoxin. Risk C: Monitor
Digoxin: Cobicistat may increase serum concentration of Digoxin. Risk C: Monitor
DilTIAZem: CYP3A4 Inhibitors (Strong) may increase serum concentration of DilTIAZem. Risk C: Monitor
Disopyramide: CYP3A4 Inhibitors (Strong) may increase serum concentration of Disopyramide. Risk C: Monitor
DOCEtaxel: CYP3A4 Inhibitors (Strong) may increase 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: CYP3A4 Inhibitors (Strong) may increase serum concentration of Dofetilide. Risk C: Monitor
Domperidone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Domperidone. Risk X: Avoid
Doxazosin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Doxazosin. Risk C: Monitor
Doxercalciferol: CYP3A4 Inhibitors (Strong) may decrease active metabolite exposure of Doxercalciferol. Risk C: Monitor
DOXOrubicin (Conventional): P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of DOXOrubicin (Conventional). Risk X: Avoid
DOXOrubicin (Liposomal): P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of DOXOrubicin (Liposomal). Risk C: Monitor
DroNABinol: CYP3A4 Inhibitors (Strong) may increase serum concentration of DroNABinol. Risk C: Monitor
Dronedarone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Dronedarone. Risk X: Avoid
Dutasteride: CYP3A4 Inhibitors (Strong) may increase serum concentration of Dutasteride. Risk C: Monitor
Duvelisib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Dydrogesterone. Risk C: Monitor
Ebastine: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Ebastine. CYP3A4 Inhibitors (Strong) may increase serum concentration of Ebastine. Risk C: Monitor
Edoxaban: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Edoxaban. Risk C: Monitor
Efonidipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Efonidipine. Risk C: Monitor
Elacestrant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Elacestrant. Risk X: Avoid
Elagolix, Estradiol, and Norethindrone: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Elagolix, Estradiol, and Norethindrone. Specifically, concentrations of elagolix may be increased. Risk X: Avoid
Elagolix: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Elagolix. Risk X: Avoid
Elbasvir and Grazoprevir: Cobicistat may increase serum concentration of Elbasvir and Grazoprevir. Risk X: Avoid
Eletriptan: CYP3A4 Inhibitors (Strong) may increase serum concentration of Eletriptan. Risk X: Avoid
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase 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 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
Eluxadoline: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Eluxadoline. Management: Decrease the eluxadoline dose to 75 mg twice daily if combined with OATP1B1/1B3 inhibitors and monitor patients for increased eluxadoline effects/toxicities. Risk D: Consider Therapy Modification
Encorafenib: Cobicistat may increase serum concentration of Encorafenib. Encorafenib may decrease serum concentration of Cobicistat. Management: Avoid this combination when possible. If combined, decrease encorafenib from 450 mg to 150 mg; or from 300 mg, 225 mg, or 150 mg to 75 mg. Additionally, monitor for reduced cobicistat efficacy and possible development of resistance. Risk D: Consider Therapy Modification
Enfortumab Vedotin: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase serum concentration of Enfortumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor
Ensartinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ensartinib. Risk X: Avoid
Ensartinib: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Ensartinib. Risk X: Avoid
Entrectinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Eplerenone. Risk X: Avoid
Erdafitinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates). Risk X: Avoid
Erlotinib: CYP3A4 Inhibitors (Strong) may increase 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): Cobicistat may increase serum concentration of Erythromycin (Systemic). Management: Consider alternatives to this combination when cobicistat is combined with atazanavir or darunavir. If combined, monitor for increased erythromycin and cobicistat effects/toxicities. Risk D: Consider Therapy Modification
Esketamine (Injection): CYP3A4 Inhibitors (Strong) may increase serum concentration of Esketamine (Injection). Risk C: Monitor
Eslicarbazepine: May decrease serum concentration of Cobicistat. Management: Consider alternatives to eslicarbazepine in patients treated with cobicistat. If coadministration cannot be avoided, monitor for loss of virologic response. Risk D: Consider Therapy Modification
Estrogen Derivatives: CYP3A4 Inhibitors (Strong) may increase serum concentration of Estrogen Derivatives. Risk C: Monitor
Eszopiclone: CYP3A4 Inhibitors (Strong) may increase 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
Ethosuximide: Cobicistat may increase serum concentration of Ethosuximide. Risk C: Monitor
Etizolam: CYP3A4 Inhibitors (Strong) may increase serum concentration of Etizolam. Risk C: Monitor
Etoposide Phosphate: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Etoposide Phosphate. Risk C: Monitor
Etoposide: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Etoposide. Risk C: Monitor
Etravirine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Etravirine. Risk C: Monitor
Everolimus: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase serum concentration of Everolimus. Risk X: Avoid
Evogliptin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Evogliptin. Risk C: Monitor
Fedratinib: CYP3A4 Inhibitors (Strong) may increase 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 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 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 active metabolite exposure 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 active metabolite exposure 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 serum concentration of Finerenone. Risk X: Avoid
Flibanserin: CYP3A4 Inhibitors (Strong) may increase 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
Flunitrazepam: CYP3A4 Inhibitors (Strong) may increase serum concentration of Flunitrazepam. Risk C: Monitor
Fluticasone (Nasal): CYP3A4 Inhibitors (Strong) may increase serum concentration of Fluticasone (Nasal). Risk X: Avoid
Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Fluticasone (Topical). Risk C: Monitor
Fluvastatin: Cobicistat may increase serum concentration of Fluvastatin. Risk C: Monitor
Fosamprenavir: Cobicistat may increase serum concentration of Fosamprenavir. However, the magnitude of this change is unclear, and dosing recommendations for this combination are not available. Risk X: Avoid
Fosaprepitant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Fosaprepitant. Risk X: Avoid
Fosphenytoin-Phenytoin: May decrease serum concentration of Cobicistat. Risk X: Avoid
Fostamatinib: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Fostamatinib. Risk C: Monitor
Futibatinib: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase serum concentration of Futibatinib. Risk X: Avoid
Gefitinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Gefitinib. Risk C: Monitor
Gepirone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Gepirone. Risk X: Avoid
Gepotidacin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Gepotidacin. Management: Avoid coadministration of gepotidacin and strong CYP3A4 inhibitors if possible. If coadministration cannot be avoided, conduct a baseline ECG, monitor closely for altered electrolytes, and correct electrolyte abnormalities as needed. Risk D: Consider Therapy Modification
Gilteritinib: CYP3A4 Inhibitors (Strong) may increase 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 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: Cobicistat may increase serum concentration of Glecaprevir and Pibrentasvir. Risk C: Monitor
GuanFACINE: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Haloperidol. Risk C: Monitor
Hormonal Contraceptives: Cobicistat may decrease serum concentration of Hormonal Contraceptives. Specifically, cobicistat may decrease serum concentrations of estrogens. Cobicistat may increase serum concentration of Hormonal Contraceptives. Specifically, cobicistat may increase serum concentrations of progestins. Management: Use alternative or additional nonhormonal forms of contraception when estrogen-containing hormonal contraceptives are combined with cobicistat. Progestin-only contraceptives can be used without back up, but monitor for progestin toxicities. Risk D: Consider Therapy Modification
HYDROcodone: CYP3A4 Inhibitors (Strong) may increase serum concentration of HYDROcodone. Risk C: Monitor
Hydrocortisone (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Hydrocortisone (Systemic). Risk C: Monitor
Ibrexafungerp: CYP3A4 Inhibitors (Strong) may increase 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 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
Idelalisib: CYP3A4 Inhibitors (Strong) may increase 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 increase adverse/toxic effects of Ifosfamide. CYP3A4 Inhibitors (Strong) may decrease active metabolite exposure of Ifosfamide. Risk C: Monitor
Iloperidone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Iloperidone. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Imatinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Imatinib. Risk C: Monitor
Imidafenacin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Imidafenacin. Risk C: Monitor
Indinavir: CYP3A4 Inhibitors (Strong) may increase serum concentration of Indinavir. Risk C: Monitor
Irinotecan Products: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure 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 active metabolite exposure of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Strong) may increase isavuconazole serum concentrations. Risk X: Avoid
Isradipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Isradipine. Risk C: Monitor
Istradefylline: CYP3A4 Inhibitors (Strong) may increase 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: May increase serum concentration of Cobicistat. Cobicistat may increase serum concentration of Itraconazole. Management: Limit itraconazole to a maximum adult dose of 200 mg/day in patients treated with the elvitegravir/cobicistat/emtricitabine/tenofovir combination products. Dosing recommendations for other cobicistat-containing products are not available. Risk D: Consider Therapy Modification
Ivabradine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ivabradine. Risk X: Avoid
Ivacaftor: CYP3A4 Inhibitors (Strong) may increase 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 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 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 serum concentration of Ketamine. Risk C: Monitor
Ketoconazole (Systemic): May increase serum concentration of Cobicistat. Cobicistat may increase serum concentration of Ketoconazole (Systemic). Management: Limit ketoconazole to a maximum adult dose of 200 mg/day in patients being treated with the elvitegravir/cobicistat/emtricitabine/tenofovir combination product. Dosing recommendations for other cobicistat-containing products are not available. Risk D: Consider Therapy Modification
Lacidipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Lacidipine. Risk C: Monitor
Lapatinib: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin tablets and strong inhibitors of CYP3A4. Risk X: Avoid
Lemborexant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Lemborexant. Risk X: Avoid
Leniolisib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Leniolisib. Risk X: Avoid
Lercanidipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Lercanidipine. Risk X: Avoid
Leuprolide and Norethindrone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Leuprolide and Norethindrone. Specifically, concentrations of norethindrone may increase. Risk C: Monitor
Levamlodipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Levamlodipine. Risk C: Monitor
Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Levobupivacaine. Risk C: Monitor
Levoketoconazole: CYP3A4 Inhibitors (Strong) may increase serum concentration of Levoketoconazole. Risk X: Avoid
Levomethadone: Cobicistat may increase serum concentration of Levomethadone. Risk C: Monitor
Levomilnacipran: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Lidocaine (Systemic). Risk C: Monitor
Lomitapide: CYP3A4 Inhibitors (Strong) may increase serum concentration of Lomitapide. Risk X: Avoid
Lonafarnib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Lonafarnib. Risk X: Avoid
Lorlatinib: CYP3A4 Inhibitors (Strong) may increase 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 active metabolite exposure of Lovastatin. CYP3A4 Inhibitors (Strong) may increase serum concentration of Lovastatin. Risk X: Avoid
Lumacaftor and Ivacaftor: May decrease serum concentration of Cobicistat. Cobicistat may increase serum concentration of Lumacaftor and Ivacaftor. Management: Consider alternatives to this combination when possible. If combined, monitor for reduced cobicistat efficacy. Lumacaftor/ivacaftor dose adjustments may be required; see full interact monograph for details. Risk D: Consider Therapy Modification
Lumateperone: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Lurasidone. Risk X: Avoid
Lurbinectedin: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Macitentan. Risk X: Avoid
Manidipine: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Mavacamten. Management: For patients on stable therapy with a strong CYP3A4 inhibitor initiate mavacamten at 2.5 mg daily. For patients initiating a strong CYP3A4 inhibitor during mavacamten therapy, dose reductions are recommended. See full mono for details. Risk D: Consider Therapy Modification
Mavorixafor: CYP3A4 Inhibitors (Strong) may increase serum concentration of Mavorixafor. Management: Decrease the mavorixafor dose to 200 mg daily if combined with strong CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Mefloquine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Mefloquine. Risk C: Monitor
Meperidine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Meperidine. Risk C: Monitor
Methadone: Cobicistat may increase serum concentration of Methadone. Risk C: Monitor
MethylPREDNISolone: CYP3A4 Inhibitors (Strong) may increase serum concentration of MethylPREDNISolone. Risk C: Monitor
Midazolam: Cobicistat may increase serum concentration of Midazolam. Management: Oral midazolam is contraindicated with cobicistat. Avoid use with nasal midazolam. Consider alternatives to use with other routes of midazolam (IV, IM) when possible. Consider use of lower midazolam doses if combined. Risk X: Avoid
Midostaurin: CYP3A4 Inhibitors (Strong) may increase 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 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 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 serum concentration of Mirtazapine. Risk C: Monitor
Mirvetuximab Soravtansine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Mirvetuximab Soravtansine. Risk C: Monitor
Mitapivat: CYP3A4 Inhibitors (Strong) may increase serum concentration of Mitapivat. Risk X: Avoid
Mobocertinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Mobocertinib. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Mobocertinib. Risk X: Avoid
Momelotinib: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Momelotinib. Risk C: Monitor
Mometasone (Nasal): CYP3A4 Inhibitors (Strong) may increase serum concentration of Mometasone (Nasal). Risk C: Monitor
Mometasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase serum concentration of Mometasone (Oral Inhalation). Risk C: Monitor
Mometasone (Topical): CYP3A4 Inhibitors (Strong) may increase serum concentration of Mometasone (Topical). Risk C: Monitor
Morphine (Systemic): P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Morphine (Systemic). Risk C: Monitor
Nadolol: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Nadolol. Risk C: Monitor
Naldemedine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Naldemedine. Risk C: Monitor
Nalfurafine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nalfurafine. Risk C: Monitor
Naloxegol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Naloxegol. Risk X: Avoid
Nelfinavir: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nelfinavir. Risk C: Monitor
Neratinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Neratinib. Risk X: Avoid
NiCARdipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of NiCARdipine. Risk C: Monitor
NIFEdipine (Topical): CYP3A4 Inhibitors (Strong) may increase serum concentration of NIFEdipine (Topical). Risk X: Avoid
NIFEdipine: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Nilotinib. Management: Avoid if possible. If coadministration cannot be avoided, nilotinib dose adjustments are recommended and depend on the dosage form of nilotinib used and indication treated. See full monograph for details. Risk D: Consider Therapy Modification
Nilvadipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nilvadipine. Risk C: Monitor
NiMODipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of NiMODipine. Risk X: Avoid
Nintedanib: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase serum concentration of Nintedanib. Risk C: Monitor
Nirmatrelvir and Ritonavir: May increase serum concentration of Cobicistat. Risk C: Monitor
Nirogacestat: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nirogacestat. Risk X: Avoid
Nisoldipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nisoldipine. Risk X: Avoid
Nitrendipine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Nitrendipine. Risk C: Monitor
Olaparib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Oliceridine. Risk C: Monitor
Olmutinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Olmutinib. Risk C: Monitor
Omaveloxolone: CYP3A4 Inhibitors (Strong) may increase 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
Orlistat: May decrease serum concentration of Antiretroviral Agents. Risk C: Monitor
Osilodrostat: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Ospemifene. Risk C: Monitor
OXcarbazepine: May decrease serum concentration of Cobicistat. Management: Consider an alternative antiseizure medication when possible. Risk D: Consider Therapy Modification
OxyBUTYnin: CYP3A4 Inhibitors (Strong) may increase serum concentration of OxyBUTYnin. Risk C: Monitor
OxyCODONE: CYP3A4 Inhibitors (Strong) may increase adverse/toxic effects of OxyCODONE. CYP3A4 Inhibitors (Strong) may increase serum concentration of OxyCODONE. Serum concentrations of the active metabolite oxymorphone may also be increased. Risk C: Monitor
PACLitaxel (Conventional): CYP3A4 Inhibitors (Strong) may increase serum concentration of PACLitaxel (Conventional). Risk C: Monitor
PACLitaxel (Protein Bound): CYP3A4 Inhibitors (Strong) may increase serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor
Pacritinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Pacritinib. Risk X: Avoid
Palbociclib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Palovarotene. Risk X: Avoid
Panobinostat: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Parecoxib. Specifically, serum concentrations of the active moiety valdecoxib may be increased. Risk C: Monitor
Paricalcitol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Paricalcitol. Risk C: Monitor
PAZOPanib: BCRP/ABCG2 Inhibitors may increase serum concentration of PAZOPanib. Risk X: Avoid
PAZOPanib: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of PAZOPanib. Risk X: Avoid
Pemigatinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Pexidartinib. Management: If combined use cannot be avoided, pexidartinib dose should be reduced as follows: 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
PHENobarbital: May decrease serum concentration of Cobicistat. Risk X: Avoid
Pimavanserin: CYP3A4 Inhibitors (Strong) may increase 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 metabolism of Pimecrolimus. Risk C: Monitor
Pimozide: CYP3A4 Inhibitors (Strong) may increase serum concentration of Pimozide. Risk X: Avoid
Piperaquine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Piperaquine. Risk C: Monitor
Pirtobrutinib: CYP3A4 Inhibitors (Strong) may increase 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
Pitavastatin: Cobicistat may increase serum concentration of Pitavastatin. Risk C: Monitor
Polatuzumab Vedotin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be increased. Risk C: Monitor
PONATinib: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Prazepam. Risk C: Monitor
Praziquantel: CYP3A4 Inhibitors (Strong) may increase serum concentration of Praziquantel. Risk C: Monitor
PrednisoLONE (Systemic): CYP3A4 Inhibitors (Strong) may increase serum concentration of PrednisoLONE (Systemic). Risk C: Monitor
PredniSONE: CYP3A4 Inhibitors (Strong) may increase serum concentration of PredniSONE. Risk C: Monitor
Primidone: May decrease serum concentration of Cobicistat. Risk X: Avoid
Propafenone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Propafenone. Risk C: Monitor
QUEtiapine: CYP3A4 Inhibitors (Strong) may increase 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 (Non-Therapeutic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Quinidine (Non-Therapeutic). Risk C: Monitor
QuiNIDine: CYP3A4 Inhibitors (Strong) may increase serum concentration of QuiNIDine. Risk C: Monitor
QuiNINE: CYP3A4 Inhibitors (Strong) may increase serum concentration of QuiNINE. Risk C: Monitor
Quizartinib: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Radotinib. Risk X: Avoid
Ramelteon: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ramelteon. Risk C: Monitor
Ranolazine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ranolazine. Risk X: Avoid
Reboxetine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Reboxetine. Risk C: Monitor
Red Yeast Rice: CYP3A4 Inhibitors (Strong) may increase serum concentration of Red Yeast Rice. Specifically, concentrations of lovastatin and related compounds found in Red Yeast Rice may be increased. Risk X: Avoid
Regorafenib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Regorafenib. CYP3A4 Inhibitors (Strong) may decrease active metabolite exposure of Regorafenib. Risk X: Avoid
Relugolix, Estradiol, and Norethindrone: P-glycoprotein/ABCB1 Inhibitors may increase 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
Relugolix: P-glycoprotein/ABCB1 Inhibitors may increase 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
Repaglinide: CYP3A4 Inhibitors (Strong) may increase serum concentration of Repaglinide. Risk C: Monitor
Repotrectinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Repotrectinib. Risk X: Avoid
Resmetirom: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Resmetirom. Risk X: Avoid
Retapamulin: CYP3A4 Inhibitors (Strong) may increase 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
Revefenacin: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase active metabolite exposure of Revefenacin. Risk X: Avoid
Revumenib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Revumenib. Management: If combined use is required, decrease revumenib dose for patients weighing 40 kg or more to 160 mg orally twice/day; for patients weighing less than 40 kg to 95 mg/m2 twice daily. Risk D: Consider Therapy Modification
Ribociclib: CYP3A4 Inhibitors (Strong) may increase 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 in advanced or metastatic breast cancer; reduce ribociclib dose to 200 mg daily in early breast cancer. Risk D: Consider Therapy Modification
Rifabutin: Cobicistat may increase serum concentration of Rifabutin. Management: Avoid if possible. Clinical practice guidelines do not recommend this combination. Cobicistat labeling recommends rifabutin 150 mg every other day. Monitor for rifabutin toxicities (eg, neutropenia, uveitis) if combined. Risk D: Consider Therapy Modification
RifAMPin: May decrease serum concentration of Cobicistat. Risk X: Avoid
Rifapentine: May decrease serum concentration of Cobicistat. Risk X: Avoid
RifAXIMin: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of RifAXIMin. Risk C: Monitor
Rilpivirine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Rilpivirine. Risk C: Monitor
Rimegepant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Rimegepant. Risk X: Avoid
Riociguat: Inhibitors of CYP3A4 (Strong) and BCRP may increase 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 BCRP 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 concentration of Ripretinib. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Ripretinib. Risk C: Monitor
RisperiDONE: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of RisperiDONE. Risk C: Monitor
Ritonavir: Cobicistat may increase therapeutic effects of Ritonavir. Specifically, cobicistat and ritonavir have overlapping effects on the CYP3A4-mediated metabolism of other drugs. Risk X: Avoid
Rivaroxaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase serum concentration of Rivaroxaban. Risk X: Avoid
Roflumilast-Containing Products: CYP3A4 Inhibitors (Strong) may increase serum concentration of Roflumilast-Containing Products. Risk C: Monitor
RomiDEPsin: CYP3A4 Inhibitors (Strong) may increase serum concentration of RomiDEPsin. Risk C: Monitor
Rosuvastatin: BCRP/ABCG2 Inhibitors may increase serum concentration of Rosuvastatin. Risk C: Monitor
Rupatadine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Rupatadine. Risk X: Avoid
Ruxolitinib (Systemic): CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Ruxolitinib (Topical). Risk X: Avoid
Salmeterol: Cobicistat may increase serum concentration of Salmeterol. Risk X: Avoid
Saquinavir: Cobicistat may increase serum concentration of Saquinavir. However, the magnitude of this change is unclear, and dosing recommendations for this combination are not available. Risk X: Avoid
SAXagliptin: CYP3A4 Inhibitors (Strong) may increase 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
Seladelpar: BCRP/ABCG2 Inhibitors may increase serum concentration of Seladelpar. Risk C: Monitor
Selpercatinib: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Sertindole. Risk X: Avoid
Sildenafil: Cobicistat may increase serum concentration of Sildenafil. Management: Use of cobicistat and sildenafil for the treatment of PAH is contraindicated. If using sildenafil for the treatment of erectile dysfunction, limit the sildenafil dose to 25 mg and do not use more frequently than every 48 hours. Risk D: Consider Therapy Modification
Silodosin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Silodosin. Risk X: Avoid
Simeprevir: CYP3A4 Inhibitors (Strong) may increase serum concentration of Simeprevir. Risk X: Avoid
Simvastatin: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Simvastatin. CYP3A4 Inhibitors (Strong) may increase serum concentration of Simvastatin. Risk X: Avoid
Sirolimus (Conventional): CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Sirolimus (Protein Bound). Risk X: Avoid
Sirolimus (Topical): CYP3A4 Inhibitors (Strong) may increase serum concentration of Sirolimus (Topical). Risk C: Monitor
Solifenacin: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Sonidegib. Risk X: Avoid
Sparsentan: CYP3A4 Inhibitors (Strong) may increase serum concentration of Sparsentan. Risk X: Avoid
St John's Wort: May decrease serum concentration of Cobicistat. Risk X: Avoid
SUFentanil: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Suvorexant. Risk X: Avoid
Suzetrigine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Suzetrigine. Risk X: Avoid
Tacrolimus (Systemic): CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Tacrolimus (Topical). Risk C: Monitor
Tadalafil: CYP3A4 Inhibitors (Strong) may increase 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: BCRP/ABCG2 Inhibitors may increase serum concentration of Talazoparib. Risk C: Monitor
Talazoparib: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Talazoparib. Risk C: Monitor
Tamsulosin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tamsulosin. Risk X: Avoid
Tasimelteon: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tasimelteon. Risk C: Monitor
Taurursodiol: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Taurursodiol. Risk X: Avoid
Tazemetostat: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tazemetostat. Risk X: Avoid
Temsirolimus: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure 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 serum concentration of Teniposide. Risk C: Monitor
Tenofovir Alafenamide: Cobicistat may increase serum concentration of Tenofovir Alafenamide. Risk C: Monitor
Tenofovir Disoproxil Fumarate: May increase adverse/toxic effects of Cobicistat. More specifically, cobicistat may impair proper tenofovir disoproxil fumarate monitoring and dosing. Risk C: Monitor
Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tetrahydrocannabinol and Cannabidiol. Risk C: Monitor
Tetrahydrocannabinol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tetrahydrocannabinol. Risk C: Monitor
Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase 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
Thioridazine: CYP2D6 Inhibitors (Weak) may increase serum concentration of Thioridazine. Management: Consider avoiding concomitant use of thioridazine and weak CYP2D6 inhibitors. If combined, monitor closely for QTc interval prolongation and arrhythmias. Some weak CYP2D6 inhibitors list use with thioridazine as a contraindication. Risk D: Consider Therapy Modification
Thiotepa: CYP3A4 Inhibitors (Strong) may decrease active metabolite exposure of Thiotepa. CYP3A4 Inhibitors (Strong) may increase 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 active metabolite exposure of Ticagrelor. CYP3A4 Inhibitors (Strong) may increase serum concentration of Ticagrelor. Risk X: Avoid
Tilidine: CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Tilidine. CYP3A4 Inhibitors (Strong) may increase serum concentration of Tilidine. Risk C: Monitor
Tipranavir: Cobicistat may increase serum concentration of Tipranavir. However, the magnitude of this change is unclear, and dosing recommendations for this combination are not available. Risk X: Avoid
Tisotumab Vedotin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Tisotumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Risk C: Monitor
Tofacitinib: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Tolvaptan. Risk X: Avoid
Topotecan: BCRP/ABCG2 Inhibitors may increase serum concentration of Topotecan. Risk X: Avoid
Topotecan: P-glycoprotein/ABCB1 Inhibitors may increase serum concentration of Topotecan. Risk X: Avoid
Toremifene: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Trabectedin. Risk X: Avoid
TraMADol: CYP3A4 Inhibitors (Strong) may increase serum concentration of TraMADol. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of TraMADol. Risk C: Monitor
TraZODone: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Tretinoin (Systemic). Management: Avoid use of tretinoin and strong CYP3A4 inhibitors when possible. If combined, monitor for increased tretinoin concentrations and toxicities (eg, pseudotumor cerebri, hypercalcemia). Risk D: Consider Therapy Modification
Triamcinolone (Nasal): CYP3A4 Inhibitors (Strong) may increase serum concentration of Triamcinolone (Nasal). Risk C: Monitor
Triamcinolone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase serum concentration of Triamcinolone (Ophthalmic). Risk C: Monitor
Triamcinolone (Systemic): CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of Triamcinolone (Topical). Risk C: Monitor
Triazolam: CYP3A4 Inhibitors (Strong) may increase serum concentration of Triazolam. Risk X: Avoid
Ubrogepant: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ubrogepant. Risk X: Avoid
Udenafil: CYP3A4 Inhibitors (Strong) may increase serum concentration of Udenafil. Risk X: Avoid
Ulipristal: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ulipristal. Risk C: Monitor
Upadacitinib: CYP3A4 Inhibitors (Strong) may increase serum concentration of Upadacitinib. Management: Upadacitinib dose adjustments are often 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 concentration of Valbenazine. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure 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 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
Vanzacaftor, Tezacaftor, and Deutivacaftor: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vanzacaftor, Tezacaftor, and Deutivacaftor. Management: Age- and weight-specific dose reductions of vanzacaftor, tezacaftor, and deutivacaftor are recommended. Please see full Interact monograph or labeling for details. Risk D: Consider Therapy Modification
Vardenafil: Cobicistat may increase serum concentration of Vardenafil. Management: Limit the dose of vardenafil tablets to a single 2.5 mg dose within a 72-hour period if combined with cobicistat. Avoid concomitant use of vardenafil orally disintegrating tablets and cobicistat. Combined use is contraindicated outside of the US. Risk D: Consider Therapy Modification
Vemurafenib: CYP3A4 Inhibitors (Strong) may increase 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 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 serum concentration of Verapamil. Risk C: Monitor
Vilanterol: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vilanterol. Risk C: Monitor
Vilazodone: CYP3A4 Inhibitors (Strong) may increase 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 serum concentration of VinBLAStine. Risk C: Monitor
VinCRIStine: CYP3A4 Inhibitors (Strong) may increase serum concentration of VinCRIStine. Risk X: Avoid
Vindesine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vindesine. Risk C: Monitor
Vinflunine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vinflunine. CYP3A4 Inhibitors (Strong) may increase active metabolite exposure of Vinflunine. Risk X: Avoid
Vinorelbine: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vinorelbine. Risk C: Monitor
Voclosporin: CYP3A4 Inhibitors (Strong) may increase serum concentration of Voclosporin. Risk X: Avoid
Vorapaxar: CYP3A4 Inhibitors (Strong) may increase serum concentration of Vorapaxar. Risk X: Avoid
Voriconazole: May increase serum concentration of Cobicistat. Cobicistat may increase serum concentration of Voriconazole. Management: Careful consideration of the risk/benefit ratio for voriconazole use is recommended prior to its use in patients who are being treated with cobicistat-containing products. If coadministered, monitor for voriconazole and cobicistat toxicity. Risk D: Consider Therapy Modification
Warfarin: Cobicistat may increase serum concentration of Warfarin. Risk C: Monitor
Zanubrutinib: CYP3A4 Inhibitors (Strong) may increase 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
Zavegepant: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentration of Zavegepant. Risk X: Avoid
Ziprasidone: CYP3A4 Inhibitors (Strong) may increase serum concentration of Ziprasidone. Risk C: Monitor
Zolpidem: CYP3A4 Inhibitors (Strong) may increase serum concentration of Zolpidem. Risk C: Monitor
Zopiclone: CYP3A4 Inhibitors (Strong) may increase 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 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
Contraception is not required to initiate or continue antiretroviral therapy. Patients with HIV not planning to become pregnant may use any available type of contraception, considering possible drug interactions and contraindications of the specific method. Consult drug interactions database for more detailed information specific to use of cobicistat and combination oral contraceptives. Concomitant use of cobicistat and atazanavir with drospirenone/ethinyl estradiol is contraindicated.
Cobicistat is not recommended as a pharmacologic booster with atazanavir, darunavir, or elvitegravir for patients with HIV who are not yet pregnant but are trying to conceive.
Maximum viral suppression sustained below the limits of detection prior to conception is recommended for all persons with HIV who are planning a pregnancy. Prior to pregnancy, select or make changes to a specific antiretroviral regimen as part of a shared decision-making process. In most cases, recommendations based on data obtained from cisgender women can be applied to transgender and gender diverse people assigned female sex at birth.
Health care providers caring for couples planning a pregnancy when one or both partners are diagnosed with HIV may contact the National Perinatal HIV Hotline (888-448-8765) for clinical consultation (HHS [perinatal] 2024).
Cobicistat has low placental transfer.
An increased risk of teratogenic effects has not been observed based on information collected by the antiretroviral pregnancy registry. Maternal antiretroviral therapy (ART) may be associated with adverse pregnancy outcomes including preterm birth, low birth weight, and small for GA infants. High viral loads are also associated with adverse outcomes, including preterm birth and pregnancy loss. Treatment improves the health of the pregnant patient and reduces the risk of perinatal transmission. Do not withhold appropriate maternal ART due to concerns for adverse neonatal outcomes. Closely monitor for pregnancy complications. Document in utero ART exposure in the long-term medical record of a child born without HIV; evaluate for potential metabolic dysfunction if significant organ system abnormalities of unknown etiology (particularly of the CNS or heart) develop.
Cobicistat exposure is decreased during pregnancy. Cobicistat is not recommended as a pharmacologic booster with atazanavir, darunavir, or elvitegravir for pregnant patients with HIV who are antiretroviral naive, who have had ART therapy in the past but are restarting, or who require a new ART regimen (due to poor tolerance or poor virologic response of current regimen). If pregnancy occurs during therapy, consideration should be given to changing to a preferred or alternative regimen. If continued in patients who are virologically suppressed, frequent viral load monitoring (every 1 to 2 months) is recommended.
ART is recommended for all pregnant people with HIV to maximize their health, maintain the viral load below the limit of an ultrasensitive assay detection, and reduce the risk of perinatal transmission. Start ART prior to conception or as soon as possible during pregnancy. During pregnancy, select or make changes to a specific antiretroviral regimen as part of a shared decision-making process. Patients on fully suppressive regimens prior to pregnancy generally may continue the same regimen considering known pregnancy outcomes and pharmacokinetic data. Monitor pregnant patients more frequently than nonpregnant patients. ART initiated during pregnancy can be modified after delivery. In most cases, recommendations based on data obtained from cisgender women can be applied to transgender and gender diverse people assigned female sex at birth.
Data collection to monitor pregnancy and infant outcomes following exposure to ART is ongoing. Enroll all patients exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (1-800-258-4263).
Health care providers caring for pregnant patients with HIV infection and their infants may contact the National Perinatal HIV Hotline (1-888-448-8765) for clinical consultation (HHS [perinatal] 2024).
It is not known if cobicistat is present in breast milk.
Provide patient-centered evidence-based counseling for infant feeding options as early as possible in pregnancy.
• Using properly prepared formula or pasteurized banked donor milk eliminates the risk of postnatal HIV transmission via breastfeeding.
• Counsel patients on antiretroviral therapy (ART) who achieve and maintain a consistently undetectable plasma viral load during pregnancy and postnatally about feeding options, including breastfeeding, formula feeding, or banked donor milk. Maintaining maximum viral suppression decreases but does not eliminate the risk of HIV transmission via breast milk. Temporary discontinuation of breastfeeding and use of replacement feeding may be required if maternal viral load becomes detectable or if mastitis or bleeding nipples develop. Permanent discontinuation of breastfeeding is recommended if the maternal HIV RNA is ≥200 copies/mL.
• Formula feeding or banked donor milk is recommended for persons with HIV who are not on ART and/or do not have sustained viral suppression. Provide the infant presumptive ART throughout breastfeeding and for up to 6 weeks after the last exposure to breast milk if the breastfeeding parent does not have sustained viral suppression but breastfeeding is continued; conduct infant virologic diagnostic testing at specified intervals.
• When the HIV status at delivery is not known, breast milk may be expressed and stored until a negative test is available.
• Discontinue breastfeeding immediately if HIV infection is diagnosed after breastfeeding has been initiated.
• Evaluate and provide support for maternal conditions that would make adherence to postpartum ART difficult.
Information is available for counseling and managing patients with HIV who are considering breastfeeding (1-888-448-8765). In most cases, recommendations based on data obtained from cisgender women can be applied to transgender and gender diverse people assigned female sex at birth (HHS [perinatal] 2024).
Take with food
CBC with differential, reticulocyte count, CD4 count, HIV RNA plasma levels, and serum creatinine at baseline and when clinically indicated during therapy; when coadministered with tenofovir disoproxil fumarate, serum creatinine, urine glucose and urine protein prior to initiation and as clinically indicated during therapy; assess serum phosphorus in patients with or at risk for renal impairment. Patients who experience a confirmed increase in serum creatinine >0.4 mg/dL from baseline should have renal function monitored closely. Testing for HBV is recommended prior to the initiation of antiretroviral therapy.
Cobicistat is a mechanism-based inhibitor of cytochrome P450 3A (CYP3A). Inhibition of CYP3A-mediated metabolism by cobicistat and increases the systemic exposure of CYP3A substrates atazanavir and darunavir.
Protein binding: 97% to 98%
Metabolism: Via CYP3A enzymes and to a minor extent by CYP2D6 enzymes and does not undergo glucuronidation
Half-life: Terminal: ~3 to 4 hours
Time to peak, plasma: ~3.5 hours
Excretion: Feces (86.2%), urine (8.2%)
Pediatric: In pediatric patients age 12 to 17 years, when used with atazanavir, both atazanavir and cobicistat exposure were higher than in adults. When used with darunavir, darunavir exposure was slightly lower than that observed in adults, while cobicistat exposure was similar. Neither of these differences were considered clinically significant.
