Cytomegalovirus (CMV), prophylaxis in allogeneic hematopoietic cell transplant (HCT) recipients: Note: Initiate between day 0 and day 28 post transplant and typically continue through 100 days post-HCT; may continue through day 200 in patients at risk for late CMV infection/disease. Duration may vary based on immune reconstitution and discontinuation of immunosuppressive therapy; consult institutional protocols (Ref).
Infants ≥6 months and Children <12 years:
IV:
6 to <7.5 kg: IV: 40 mg once daily.
7.5 to <15 kg: IV: 60 mg once daily.
15 to <30 kg: IV: 120 mg once daily.
≥30 kg: IV: 480 mg once daily.
Oral:
6 to <7.5 kg: Oral pellets: Oral: 80 mg once daily.
7.5 to <15 kg: Oral pellets: Oral: 120 mg once daily.
15 to <30 kg: Oral pellets, tablets: Oral: 240 mg once daily.
≥30 kg: Oral pellets, tablets: Oral: 480 mg once daily (Ref).
Children ≥12 years and Adolescents:
15 to <30 kg:
IV: 120 mg once daily.
Oral: Oral pellets, tablets: 240 mg once daily.
≥30 kg: IV, Oral: 480 mg once daily (Ref).
Cytomegalovirus (CMV), prophylaxis in kidney transplant recipients:
High-risk recipients (donor CMV seropositive/recipient CMV seronegative [D+/R-]):
Children ≥12 years and Adolescents, weighing ≥40 kg: IV, Oral: 480 mg once daily beginning between day 0 and 7 post kidney transplant; continue through day 200 post transplantation.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Infants ≥6 months, Children, and Adolescents:
eGFR >10 mL/minute/1.73 m2:
Oral: No dosage adjustment necessary.
IV: No dosage adjustment necessary; use with caution and monitor serum creatinine closely in patients with eGFR <50 mL/minute/1.73 m2 due to potential accumulation of IV vehicle (hydroxypropyl betadex).
eGFR ≤10 mL/minute/1.73 m2: Oral, IV: There are no specific dosage adjustments provided in the manufacturer's labeling; data are insufficient to make dosage recommendations.
ESRD on dialysis: Oral, IV: There are no specific dosage adjustments provided in the manufacturer's labeling; data are insufficient to make dosage recommendations.
Infants ≥6 months, Children, and Adolescents: Oral, IV:
Mild or moderate impairment: No dosage adjustment necessary.
Severe impairment: Use is not recommended.
(For additional information see "Letermovir: Drug information")
Cytomegalovirus, prophylaxis in hematopoietic cell transplant recipients: IV, Oral: 480 mg once daily beginning between day 0 and day 28 postallogeneic hematopoietic cell transplant for cytomegalovirus (CMV)-seropositive recipients; continue through day 100 post transplantation (Ref). Use may be continued through day 200 post transplantation in patients at risk for late CMV infection and disease.
Cytomegalovirus, prophylaxis in kidney transplant recipients: IV, Oral: 480 mg once daily beginning between day 0 and 7 post kidney transplant for high-risk recipients (donor CMV seropositive/recipient CMV seronegative); continue through day 200 post transplantation (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Note: The Cockcroft-Gault equation should be used to estimate renal function.
CrCl >10 mL/minute:
Oral: No dosage adjustment necessary.
IV: No dosage adjustment necessary; use with caution and closely monitor serum creatinine in patients with CrCl <50 mL/minute due to potential accumulation of IV vehicle (hydroxypropyl betadex).
CrCl ≤10 mL/minute: There are no specific dosage adjustments provided in the manufacturer's labeling; data are insufficient to make dosage recommendations. Closely monitor serum creatinine due to potential accumulation of IV vehicle (hydroxypropyl betadex).
ESRD on dialysis: There are no specific dosage adjustments provided in the manufacturer's labeling; data are insufficient to make dosage recommendations.
Mild or moderate impairment (Child-Pugh class A or B): No dosage adjustment necessary.
Severe impairment (Child-Pugh class C): Use is not recommended.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Reported adverse reactions are for adults.
>10%:
Cardiovascular: Cardiac abnormality (13%; including atrial fibrillation [3%], tachycardia [4%]), peripheral edema (14%)
Gastrointestinal: Abdominal pain (12%), diarrhea (26%), nausea (27%), vomiting (19%)
Hematologic & oncologic: Decreased platelet count (<25,000 cells/mcL: 27%; 25,000 to <50,000 cells/mcL: 17%; 50,000 to <100,000 cells/mcL: 20%) (table 1)
Drug (Letermovir) |
Placebo |
Indication |
Number of Patients (Letermovir) |
Number of Patients (Placebo) |
Comments |
---|---|---|---|---|---|
27% |
21% |
Prophylaxis of cytomegalovirus (CMV) infection and disease in adult CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant |
373 |
192 |
<25,000 cells/mcL |
20% |
30% |
Prophylaxis of CMV infection and disease in adult CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant |
373 |
192 |
50,000 to <100,000 cells/mcL |
17% |
18% |
Prophylaxis of CMV infection and disease in adult CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant |
373 |
192 |
25,000 to <50,000 cells/mcL |
Nervous system: Fatigue (13%), headache (14%)
Respiratory: Cough (14%)
1% to 10%: Hematologic & oncologic: Decreased hemoglobin (<6.5 g/dL: 2%)
<1%: Hypersensitivity: Hypersensitivity reaction
Concomitant administration with pimozide or ergot alkaloids; concomitant administration with pitavastatin and simvastatin when coadministered with cyclosporine.
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): Hypersensitivity to letermovir or any component of the formulation; concomitant administration with bosentan, lovastatin, and rosuvastatin when coadministered with cyclosporine.
Disease-related concerns:
• Hepatic impairment: Use is not recommended in patients with severe impairment (Child-Pugh class C).
• Renal impairment: Use with caution and closely monitor serum creatinine in patients with CrCl <50 mL/minute; accumulation of IV vehicle, hydroxypropyl betadex, may occur. Data are insufficient to make dosage recommendations in patients with CrCl ≤10 mL/minute or in patients on dialysis.
Dosage form specific issues:
• Injection: Contains hydroxypropyl betadex; use injection only in patients unable to take oral therapy.
Other warnings/precautions:
• Appropriate use: Not active against other herpes viruses besides cytomegalovirus (CMV) (Marschall 2012). Additional prophylaxis targeting herpes simplex virus (HSV) in HSV-positive transplant recipients receiving letermovir may be necessary (ASBMT [Tomblyn 2009]; Limaye 2023; Marty 2017).
• Resistance: Patients may have resistance to letermovir due to mutations in UL56. Cross resistance does not occur in populations with substitutions conferring resistance to CMV DNA polymerase inhibitors such as ganciclovir, cidofovir, and foscarnet.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Packet, Oral:
Prevymis: 20 mg (1 ea, 30 ea); 120 mg (1 ea, 30 ea)
Solution, Intravenous [preservative free]:
Prevymis: 240 mg/12 mL (12 mL); 480 mg/24 mL (24 mL)
Tablet, Oral:
Prevymis: 240 mg, 480 mg
No
Pack (Prevymis Oral)
20 mg (per each): $13.72
120 mg (per each): $82.32
Solution (Prevymis Intravenous)
240MG/12ML (per mL): $37.94
480MG/24ML (per mL): $18.97
Tablets (Prevymis Oral)
240 mg (per each): $329.27
480 mg (per each): $329.27
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.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Intravenous:
Prevymis: 240 mg/12 mL (12 mL); 480 mg/24 mL (24 mL)
Tablet, Oral:
Prevymis: 240 mg, 480 mg
Oral:
Oral pellets: Do not crush or chew pellets. Determine number of oral pellet packet(s) needed for dose. Open packet(s) and empty all contents into a bowl; mix with 1 to 3 teaspoons of soft food (eg, applesauce, yogurt, pudding); food should be at or below room temperature; do not use hot food. Gently mix oral pellets and food together and administer entire mixture. If pellets are left in the container or on the spoon used to prepare and administer oral pellets, add more soft food, stir, and administer to ensure delivery of the entire dose. Mixture must be administered within 10 minutes of preparation; if not administered within 10 minutes, then mixture must be discarded and new dose must be prepared.
Administration via feeding tube: Tube type and size and preparation are based on dose. Dose must be administered within 2 hours of preparation; if mixture is not administered within 2 hours of preparation, discard mixture and prepare new dose.
20 mg oral pellet packets (40 to 80 mg dose):
Gastric tubes (5 French polyurethane NG, any ≥6 French NG, or any 12 French G-tube): Open packets and pour oral pellets into a medicine cup with 3 mL room temperature purified water; do not use hot or cold (refrigerated) water. Allow mixture to stand for 10 minutes; do not shake or swirl; oral pellets will become loose or broken up but will not dissolve. Gently stir mixture with tip of enteral dosing syringe. Draw up entire mixture in enteral dosing syringe; gently invert syringe to keep pellets from settling and administer immediately; do not shake the syringe (may cause air bubbles). Add 2 mL of room temperature purified water to the medicine cup; using same syringe, stir with tip, draw up rinse and administer contents to ensure delivery of entire dose. Flush feeding tube with an appropriate volume of purified water.
120 mg oral pellet packets (120 to 480 mg dose):
Gastric tubes (any ≥8 French NG or ≥12 French G-tube): Open packets and pour oral pellets into a medicine cup with 15 mL room temperature purified water; do not use hot or cold (refrigerated) water. Allow mixture to stand for 10 minutes; do not shake or swirl; oral pellets will become loose or broken up but will not dissolve. Gently stir mixture with tip of enteral dosing syringe. Draw up entire mixture in enteral dosing syringe; gently invert syringe to keep pellets from settling and administer immediately; do not shake the syringe (may cause air bubbles). Add 15 mL of room temperature purified water to the medicine cup; using same syringe, stir with tip, draw up rinse and administer contents to ensure delivery of entire dose. Flush feeding tube with an appropriate volume of purified water.
Tablets: Administer with or without food; swallow tablet whole per the manufacturer.
Administration via feeding tube:
Gastric tubes (eg, NG, G-tube): Crush tablets into a fine powder and disperse in 15 to 30 mL purified water; draw up mixture into enteral dosing syringe and administer via feeding tube (Ref).
Dosage form information: Tablets are film-coated; administration of film-coated tablets via feeding tube may increase the risk of clogging the tube; use caution (Ref).
Parenteral: IV: Infuse over 1 hour through a peripheral or central venous catheter; do not administer as IV bolus. Infuse via a 0.2- or 0.22-micron polyethersulfone in-line filter. Not compatible with polyurethane- or DEHP-containing IV administration sets; refer to manufacturer's labeling for compatible infusion sets.
Oral:
Pellets: Do not crush or chew. Mix pellets with 1 to 3 teaspoons of soft food (eg, applesauce, yogurt, pudding); use at or below room temperature food; do not use hot food. Administer mixture within 10 minutes of preparation.
Administration via feeding tube: Tube type and size and preparation are dose dependent. Administer within 2 hours of preparation.
120 mg oral pellet packets (120 to 480 mg dose):
Gastric (any ≥8 French NG or any G-tube) tubes: Open packets and pour pellets into a medicine cup with 15 mL room temperature purified water; do not use hot or cold (refrigerated) water. Allow mixture to stand for 10 minutes; do not shake or swirl; pellets will become loose or broken up but will not dissolve. Gently stir mixture with tip of enteral dosing syringe. Draw up entire mixture in enteral dosing syringe; gently invert syringe to keep pellets from settling and administer immediately; do not shake the syringe (may cause air bubbles). Add 15 mL of room temperature purified water to the medicine cup; using same syringe, stir with tip, draw up rinse mixture and administer contents to ensure delivery of entire dose. Flush feeding tube with an appropriate volume of purified water.
Tablet: Administer with or without food; swallow whole.
IV: Infuse as an IV infusion over 1 hour through a peripheral or central venous catheter; do not administer as IV bolus. Infuse via a 0.2- or 0.22-micron polyethersulfone in-line filter. Not compatible with polyurethane-containing IV administration sets; refer to manufacturer's labeling for compatible infusion sets.
Injection: Store intact vials at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from light; do not shake intact vials. Diluted solution is stable for ≤24 hours at room temperature or ≤48 hours at 2°C to 8°C (36°F to 46°F), including infusion time.
Oral pellets: Store in original packet at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).
Tablets: Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Store in original container to protect from moisture.
Prophylaxis of cytomegalovirus (CMV) infection and disease in CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant (FDA approved in ages ≥6 months and weighing ≥6 kg and adults); prophylaxis of CMV disease in kidney transplant recipients at high risk (donor CMV seropositive/recipient CMV seronegative [D+/R-]) (FDA approved in ages ≥12 years and weighing ≥40 kg and adults).
Substrate of CYP2D6 (Minor), CYP3A4 (Minor), OATP1B1/1B3, P-glycoprotein (Major with inducers), P-glycoprotein (Minor with inhibitors), UGT1A1, UGT1A3; Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits CYP3A4 (Moderate);
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.
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
Abemaciclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Abemaciclib. Management: Monitor for increased abemaciclib toxicities if combined with moderate CYP3A4 inhibitors. Consider reducing the abemaciclib dose in 50 mg decrements if necessary. Risk C: Monitor
Acalabrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Acalabrutinib. Management: Reduce acalabrutinib dose to 100 mg once daily with concurrent use of a moderate CYP3A4 inhibitor. Monitor patient closely for both acalabrutinib response and evidence of adverse effects with any concurrent use. Risk D: Consider Therapy Modification
Acrivastine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Acrivastine. Risk C: Monitor
Adagrasib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Adagrasib. Risk C: Monitor
ALfentanil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ALfentanil. Management: If use of alfentanil and moderate 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 (Moderate) may increase serum concentration of Alfuzosin. Risk C: Monitor
Alitretinoin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Alitretinoin (Systemic). Risk C: Monitor
ALPRAZolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ALPRAZolam. Management: Consider alternatives to this combination when possible. If combined, consider an alprazolam dose reduction and monitor for increased alprazolam effects and toxicities (eg, sedation, lethargy). Risk D: Consider Therapy Modification
Amiodarone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Amiodarone. Risk C: Monitor
AmLODIPine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of AmLODIPine. Risk C: Monitor
Apixaban: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Apixaban. Risk C: Monitor
Aprepitant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Aprepitant. Risk X: Avoid
ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ARIPiprazole Lauroxil. Risk C: Monitor
ARIPiprazole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy, indication, or dosage form. Consult full interaction monograph for specific recommendations. Risk C: Monitor
Asciminib: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Atazanavir: May increase serum concentration of UGT1A1 Substrates. Management: Do not use UGT1A1 substrates for which small increases in exposure can cause serious adverse effects together with atazanavir, and use caution with any UGT1A1 substrate, even when small changes in exposure are less likely to cause serious adverse effects. Risk D: Consider Therapy Modification
Atogepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Atogepant. Risk C: Monitor
Atorvastatin: Letermovir may increase serum concentration of Atorvastatin. Management: Limit the atorvastatin dose to 20 mg daily when combined with letermovir. When letermovir is coadministered with cyclosporine, the use of atorvastatin (at any dose) is not recommended. Risk D: Consider Therapy Modification
Avacopan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Avacopan. Risk C: Monitor
Avanafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Avanafil. Management: The maximum avanafil dose is 50 mg per 24-hour period when used together with a moderate CYP3A4 inhibitor. Patients receiving such a combination should also be monitored more closely for evidence of adverse effects (eg, hypotension, syncope, priapism). Risk D: Consider Therapy Modification
Avapritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Avapritinib. Management: Avoid use of moderate CYP3A4 inhibitors with avapritinib. If this combination cannot be avoided, reduce the avapritinib dose to 100 mg daily for the treatment of GIST or to 50 mg daily for the treatment of advanced systemic mastocytosis. Risk D: Consider Therapy Modification
Axitinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Axitinib. Risk C: Monitor
Barnidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Barnidipine. Risk C: Monitor
Bedaquiline: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bedaquiline. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Bedaquiline. Risk C: Monitor
Belumosudil: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Management: Avoid coadministration of belumosudil with these substrates of OATP1B1/1B3 for which minimal concentration increases can cause serious adverse effects. If coadministration is required, dose reductions of the OATP1B1/1B3 substrate may be required. Risk D: Consider Therapy Modification
Benidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Benidipine. Risk C: Monitor
Benzhydrocodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Risk C: Monitor
Blonanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Blonanserin. Risk C: Monitor
Bortezomib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bortezomib. Risk C: Monitor
Bosentan: May decrease serum concentration of Letermovir. Risk X: Avoid
Bosutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bosutinib. Risk X: Avoid
Brexpiprazole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Brexpiprazole. Management: The brexpiprazole dose should be reduced to 25% of usual if used together with both a moderate CYP3A4 inhibitor and a strong or moderate CYP2D6 inhibitor, or if a moderate CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer. Risk C: Monitor
Brigatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with moderate CYP3A4 inhibitors when possible. If such a combination cannot be avoided, reduce the dose of brigatinib by approximately 40% (ie, from 180 mg to 120 mg, from 120 mg to 90 mg, or from 90 mg to 60 mg). Risk D: Consider Therapy Modification
Bromocriptine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bromocriptine. Management: The bromocriptine dose should not exceed 1.6 mg daily with use of a moderate CYP3A4 inhibitor. The Cycloset brand specifically recommends this dose limitation, but other bromocriptine products do not make such specific recommendations. Risk D: Consider Therapy Modification
Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Oral Inhalation). Risk C: Monitor
Budesonide (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Systemic). Management: Avoid the concomitant use of CYP3A4 inhibitors and oral budesonide. If patients receive both budesonide and CYP3A4 inhibitors, they should be closely monitored for signs and symptoms of corticosteroid excess. Risk D: Consider Therapy Modification
Budesonide (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Topical). Risk X: Avoid
Bulevirtide: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Management: Coadministration of bulevirtide with OATP1B1/1B3 (also known as SLCO1B1/1B3) substrates should be avoided when possible. If used together, close clinical monitoring is recommended. Risk D: Consider Therapy Modification
Buprenorphine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Buprenorphine. Risk C: Monitor
BusPIRone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of BusPIRone. Risk C: Monitor
Cabozantinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cabozantinib. Risk C: Monitor
Cannabis: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Risk C: Monitor
Capivasertib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Capivasertib. Management: If capivasertib is combined with moderate CYP3A4 inhibitors, 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
Cariprazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cariprazine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Cariprazine. Management: Cariprazine dose adjustments are recommended and depend upon whether a patient is initiating a moderate 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
Ceftobiprole Medocaril: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk X: Avoid
Ceritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ceritinib. Risk C: Monitor
Cilostazol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cilostazol. Management: Decrease the dose of cilostazol to 50 mg twice daily when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Cisapride: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cisapride. Management: Consider alternatives to this combination. Prescribing information for some moderate CYP3A4 inhibitors state coadministration with cisapride is contraindicated, while some others recommend monitoring and dose titration. Risk D: Consider Therapy Modification
Clindamycin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Clindamycin (Systemic). Risk C: Monitor
CloZAPine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of CloZAPine. Risk C: Monitor
Cobimetinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cobimetinib. Management: Avoid this combination when possible. If concurrent short term (14 days or less) use cannot be avoided, reduce the cobimetinib dose from 60 mg to 20 mg daily. Avoid concomitant use in patients already receiving reduced cobimetinib doses. Risk D: Consider Therapy Modification
Codeine: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Codeine. Risk C: Monitor
Colchicine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Colchicine. Management: Avoidance, dose reduction, or increased monitoring for colchicine toxicity may be needed and will depend on brand, indication for colchicine use, renal/hepatic function, and use of a P-gp inhibitor. See full monograph for details. Risk D: Consider Therapy Modification
Conivaptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Conivaptan. Risk C: Monitor
Copanlisib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Copanlisib. Risk C: Monitor
Crizotinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Crizotinib. Risk C: Monitor
CycloSPORINE (Systemic): Letermovir may increase serum concentration of CycloSPORINE (Systemic). CycloSPORINE (Systemic) may increase serum concentration of Letermovir. Management: Letermovir dose reductions are required during coadministration with cyclosporine which depend on indication, age, and weight. See full mono for details. Monitor for increased cyclosporine concentrations and toxicities during coadministration. Risk D: Consider Therapy Modification
Dabrafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dabrafenib. Risk C: Monitor
Dapoxetine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dapoxetine. Management: The dose of dapoxetine should be limited to 30 mg per day when used together with a moderate inhibitor of CYP3A4. Risk D: Consider Therapy Modification
Daridorexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Daridorexant. Management: Limit the daridorexant dose to 25 mg, no more than once per night, when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Darifenacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Darifenacin. Risk C: Monitor
Darolutamide: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Dasatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dasatinib. Risk C: Monitor
Deflazacort: CYP3A4 Inhibitors (Moderate) 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 (Moderate) may increase serum concentration of Delamanid. Risk C: Monitor
DexAMETHasone (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of DexAMETHasone (Systemic). Risk C: Monitor
DiazePAM: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DiazePAM. Risk C: Monitor
Diazoxide Choline: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Diazoxide Choline. Risk C: Monitor
Dienogest: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dienogest. Risk C: Monitor
DilTIAZem: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DilTIAZem. Risk C: Monitor
Disopyramide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Disopyramide. Risk C: Monitor
DOCEtaxel: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DOCEtaxel. Risk C: Monitor
Dofetilide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dofetilide. Risk C: Monitor
Domperidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Domperidone. Risk X: Avoid
DOXOrubicin (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of DOXOrubicin (Conventional). Risk X: Avoid
DroNABinol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DroNABinol. Risk C: Monitor
Dronedarone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dronedarone. Risk C: Monitor
Ebastine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ebastine. Risk C: Monitor
Elacestrant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elacestrant. Risk X: Avoid
Elbasvir and Grazoprevir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elbasvir and Grazoprevir. Risk C: Monitor
Eletriptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eletriptan. Risk X: Avoid
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: When combined with moderate CYP3A4 inhibitors, elexacaftor/tezacaftor/ivacaftor should be given in the morning, every other day. Ivacaftor alone should be given in the morning, every other day on alternate days. Risk D: Consider Therapy Modification
Eliglustat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eliglustat. Management: Reduce eliglustat dose to 84 mg daily in CYP2D6 EMs when used with moderate CYP3A4 inhibitors. Avoid use of moderate CYP3A4 inhibitors in CYP2D6 IMs or PMs. Use in CYP2D6 EMs or IMs also taking strong or moderate CYP2D6 inhibitors is contraindicated. Risk D: Consider Therapy Modification
Eltrombopag: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Encorafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Encorafenib. Management: Avoid use of encorafenib and moderate CYP3A4 inhibitors when possible. If combined, decrease the encorafenib dose from 450 mg to 225 mg; 300 mg to 150 mg; and 225 mg or 150 mg to 75 mg. Resume prior dose once inhibitor discontinued for 3 to 5 half-lives. Risk D: Consider Therapy Modification
Ensartinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ensartinib. Risk X: Avoid
Entrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Entrectinib. Management: Avoid moderate CYP3A4 inhibitors if possible. If needed, reduce entrectinib dose to 50 mg/day if starting dose 200 mg; to 100 mg/day if starting dose 300 mg; to 200 mg if starting dose 400 mg or 600 mg. Risk D: Consider Therapy Modification
Eplerenone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eplerenone. Management: If coadministered with moderate CYP3A4 inhibitors, the max dose of eplerenone is 25 mg daily if used for heart failure; if used for hypertension initiate eplerenone 25 mg daily, titrate to max 25 mg twice daily. Risk D: Consider Therapy Modification
Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates): Letermovir may increase serum concentration of Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates). Risk X: Avoid
Erlotinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Erlotinib. Risk C: Monitor
Erythromycin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Erythromycin (Systemic). Risk C: Monitor
Eszopiclone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eszopiclone. Risk C: Monitor
Etravirine: May decrease serum concentration of Letermovir. Risk X: Avoid
Everolimus: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Everolimus. Risk C: Monitor
Fedratinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fedratinib. Risk C: Monitor
Felodipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Felodipine. Risk C: Monitor
FentaNYL: CYP3A4 Inhibitors (Moderate) may increase serum concentration of FentaNYL. Management: Consider fentanyl dose reductions when combined with a moderate 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
Fexinidazole: CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Fexinidazole. Management: Avoid use of fexinidazole and moderate CYP3A4 inhibitors when possible. If combined, monitor for reduced fexinidazole efficacy. Risk D: Consider Therapy Modification
Finerenone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Finerenone. Risk C: Monitor
Flibanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Flibanserin. Management: Use of flibanserin with moderate 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
Fluticasone (Nasal): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fluticasone (Nasal). Risk C: Monitor
Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fluticasone (Oral Inhalation). Risk C: Monitor
Fosamprenavir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fosamprenavir. Risk C: Monitor
Fosaprepitant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fosaprepitant. Risk X: Avoid
Gemfibrozil: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Gepirone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gepirone. Management: Reduce the gepirone dose by 50% if combined with moderate CYP3A4 inhibitors. Monitor for QTc interval prolongation with combined use. Risk D: Consider Therapy Modification
Gepotidacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gepotidacin. Risk C: Monitor
Gilteritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gilteritinib. Risk C: Monitor
Glasdegib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Glasdegib. Risk C: Monitor
GlyBURIDE: Letermovir may increase serum concentration of GlyBURIDE. Risk C: Monitor
GuanFACINE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of GuanFACINE. Management: Reduce the extended-release guanfacine dose 50% when combined with a moderate CYP3A4 inhibitor. Monitor for increased guanfacine toxicities when these agents are combined. Risk D: Consider Therapy Modification
Halofantrine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Halofantrine. Risk C: Monitor
HMG-CoA Reductase Inhibitors (Statins): Letermovir may increase serum concentration of HMG-CoA Reductase Inhibitors (Statins). Risk C: Monitor
HYDROcodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of HYDROcodone. Risk C: Monitor
Ibrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ibrutinib. Management: When treating B-cell malignancies, decrease ibrutinib to 280 mg daily when combined with moderate CYP3A4 inhibitors. When treating graft versus host disease, monitor patients closely and reduce the ibrutinib dose as needed based on adverse reactions. Risk D: Consider Therapy Modification
Ifosfamide: CYP3A4 Inhibitors (Moderate) may increase adverse/toxic effects of Ifosfamide. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Ifosfamide. Risk C: Monitor
Iloperidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Iloperidone. Risk C: Monitor
Irinotecan Products: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Irinotecan Products. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Irinotecan Products. Specifically, the serum concentration of SN-38 may be increased. Risk C: Monitor
Isavuconazonium Sulfate: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Moderate) may increase isavuconazole serum concentrations. Risk C: Monitor
Isradipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Isradipine. Risk C: Monitor
Itraconazole: May increase serum concentration of Letermovir. Letermovir may decrease serum concentration of Itraconazole. Risk C: Monitor
Ivabradine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivabradine. Risk X: Avoid
Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivacaftor. Management: Ivacaftor dose reductions may be required; consult full drug interaction monograph content for age- and weight-specific dosage recommendations. Risk D: Consider Therapy Modification
Ivosidenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivosidenib. Management: Avoid use of moderate CYP3A4 inhibitors with ivosidenib whenever possible. If combined, monitor for increased ivosidenib toxicities, including QTc prolongation. Risk D: Consider Therapy Modification
Ixabepilone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ixabepilone. Risk C: Monitor
Lapatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lapatinib. Risk C: Monitor
Larotrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Larotrectinib. Risk C: Monitor
Lefamulin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lefamulin. Management: Monitor for lefamulin adverse effects during coadministration of lefamulin tablets with moderate CYP3A4 inhibitors. Risk C: Monitor
Leflunomide: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Lemborexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lemborexant. Risk X: Avoid
Leniolisib: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk X: Avoid
Lercanidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lercanidipine. Risk C: Monitor
Levamlodipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levamlodipine. Risk C: Monitor
Levoketoconazole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levoketoconazole. Risk C: Monitor
Levomethadone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levomethadone. Risk C: Monitor
Levomilnacipran: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levomilnacipran. Risk C: Monitor
Lidocaine (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lidocaine (Systemic). CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Lidocaine (Systemic). Specifically, concentrations of monoethylglycinexylidide (MEGX) may be increased. Risk C: Monitor
Lomitapide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lomitapide. Risk X: Avoid
Lonafarnib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lonafarnib. Risk C: Monitor
Lovastatin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lovastatin. Risk C: Monitor
Lumacaftor and Ivacaftor: May increase serum concentration of P-glycoprotein/ABCB1 Substrates (High risk with Inhibitors or Inducers). Lumacaftor and Ivacaftor may decrease serum concentration of P-glycoprotein/ABCB1 Substrates (High risk with Inhibitors or Inducers). Risk C: Monitor
Lumateperone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lumateperone. Management: Limit the lumateperone dose to 21 mg once daily when used with a moderate CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Lurasidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lurasidone. Management: Reduce the lurasidone dose by half when initiating therapy with a moderate CYP3A4 inhibitor. If initiating lurasidone in a patient already receiving a moderate CYP3A4 inhibitor, start lurasidone at 20 mg/day with a max dose of 80 mg/day. Risk D: Consider Therapy Modification
Lurbinectedin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lurbinectedin. Management: Avoid concomitant use of lurbinectedin and moderate CYP3A4 inhibitors when possible. If combined, reduce the lurbinectedin dose by 50%. Risk D: Consider Therapy Modification
Macitentan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Macitentan. Risk C: Monitor
Manidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Manidipine. Risk C: Monitor
Maraviroc: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Maraviroc. Risk C: Monitor
Mavacamten: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mavacamten. Management: Start mavacamten at 5 mg/day if stable on a moderate CYP3A4 inhibitor, and reduce the mavacamten dose by one dose level if initiating a moderate CYP3A4 inhibitor. Avoid initiating moderate CYP3A4 inhibitors in patients on mavacamten 2.5 mg/day. Risk D: Consider Therapy Modification
Mavorixafor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mavorixafor. Risk C: Monitor
Meperidine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Meperidine. Risk C: Monitor
Methadone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Methadone. Management: If coadministration with moderate CYP3A4 inhibitors is necessary, consider methadone dose reductions until stable effects are achieved. Monitor patients closely for respiratory depression and sedation. Risk D: Consider Therapy Modification
MethylPREDNISolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of MethylPREDNISolone. Risk C: Monitor
Methysergide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Methysergide. Risk X: Avoid
Midazolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Midazolam. Management: Avoid concomitant use of nasal midazolam and moderate CYP3A4 inhibitors. Consider alternatives to use with oral midazolam whenever possible and consider using lower midazolam doses. Monitor patients for sedation and respiratory depression if combined. Risk D: Consider Therapy Modification
Midostaurin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Midostaurin. Risk C: Monitor
MiFEPRIStone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of MiFEPRIStone. Risk C: Monitor
Mirodenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mirodenafil. Risk C: Monitor
Mitapivat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mitapivat. Management: When coadministered with moderate CYP3A4 inhibitors, doses of mitapivat should not exceed 20 mg twice daily. Additionally, patients should be monitored for changes in hemoglobin response and increased mitapivat adverse effects. Risk D: Consider Therapy Modification
Mobocertinib: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Mobocertinib. CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mobocertinib. Management: Avoid use of moderate CYP3A4 inhibitors with mobocertinib when possible. If combined, the mobocertinib dose should be reduced by approximately 50% (ie, from 160 mg to 80 mg, 120 mg to 40 mg, or 80 mg to 40 mg). Monitor QTc interval closely. Risk D: Consider Therapy Modification
Modafinil: May decrease serum concentration of Letermovir. Risk X: Avoid
Nafcillin: May decrease serum concentration of Letermovir. Risk X: Avoid
Naldemedine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Naldemedine. Risk C: Monitor
Nalfurafine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nalfurafine. Risk C: Monitor
Naloxegol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Naloxegol. Management: The use of naloxegol and moderate CYP3A4 inhibitors should be avoided. If concurrent use is unavoidable, reduce naloxegol dose to 12.5 mg once daily and monitor for signs of opiate withdrawal (eg, hyperhidrosis, chills, diarrhea, anxiety, irritability). Risk D: Consider Therapy Modification
Neratinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Neratinib. Risk C: Monitor
Nevirapine: May decrease therapeutic effects of Letermovir. Risk X: Avoid
NIFEdipine (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of NIFEdipine (Topical). Risk C: Monitor
NIFEdipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of NIFEdipine. Risk C: Monitor
NiMODipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of NiMODipine. Risk C: Monitor
Nirogacestat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nirogacestat. Risk X: Avoid
Nisoldipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nisoldipine. Risk X: Avoid
Nitrendipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nitrendipine. Risk C: Monitor
Olaparib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Olaparib. Management: Avoid use of moderate CYP3A4 inhibitors with olaparib, if possible. If such concurrent use cannot be avoided, the dose of olaparib tablets should be reduced to 150 mg twice daily and the dose of olaparib capsules should be reduced to 200 mg twice daily. Risk D: Consider Therapy Modification
Oliceridine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Oliceridine. Risk C: Monitor
Olmutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Olmutinib. Risk C: Monitor
Omaveloxolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Omaveloxolone. Management: Avoid this combination if possible. If coadministration is required, decrease the omaveloxolone dose to 100 mg daily and monitor closely for adverse reactions. If adverse reactions occur, decrease omaveloxolone to 50 mg daily. Risk D: Consider Therapy Modification
OxyCODONE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of OxyCODONE. Serum concentrations of the active metabolite Oxymorphone may also be increased. Risk C: Monitor
P-glycoprotein/ABCB1 Inducers: May decrease serum concentration of Letermovir. Risk X: Avoid
PACLitaxel (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of PACLitaxel (Conventional). Risk C: Monitor
PACLitaxel (Protein Bound): CYP3A4 Inhibitors (Moderate) may increase serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor
Pacritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pacritinib. Risk C: Monitor
Palbociclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Palbociclib. Risk C: Monitor
Palovarotene: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Palovarotene. Management: Avoid concomitant use of palovarotene and moderate CYP3A4 inhibitors when possible. If combined, decrease palovarotene dose by 50% as described in the full interaction monograph. Monitor for palovarotene toxicities when combined. Risk D: Consider Therapy Modification
Panobinostat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Panobinostat. Risk C: Monitor
PAZOPanib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of PAZOPanib. Risk C: Monitor
Pemigatinib: CYP3A4 Inhibitors (Moderate) 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 moderate inhibitor once 3 half-lives of the inhibitor has passed. Risk D: Consider Therapy Modification
Pexidartinib: CYP3A4 Inhibitors (Moderate) 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
Pimavanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pimavanserin. Risk C: Monitor
Pimecrolimus: CYP3A4 Inhibitors (Moderate) may decrease metabolism of Pimecrolimus. Risk C: Monitor
Pimozide: Letermovir may increase serum concentration of Pimozide. Risk X: Avoid
Piperaquine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Piperaquine. Risk C: Monitor
Pirtobrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pirtobrutinib. Risk C: Monitor
Pitavastatin: Letermovir may increase serum concentration of Pitavastatin. Risk X: Avoid
PONATinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of PONATinib. Risk C: Monitor
Pralsetinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pralsetinib. Management: If this combo cannot be avoided, decrease pralsetinib dose from 400 mg daily to 300 mg daily; from 300 mg daily to 200 mg daily; and from 200 mg daily to 100 mg daily. Risk D: Consider Therapy Modification
Prazepam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Prazepam. Risk C: Monitor
Praziquantel: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Praziquantel. Risk C: Monitor
Pretomanid: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
QUEtiapine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QUEtiapine. Risk C: Monitor
Quinidine (Non-Therapeutic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Quinidine (Non-Therapeutic). Risk C: Monitor
QuiNIDine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QuiNIDine. Risk C: Monitor
QuiNINE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QuiNINE. Risk C: Monitor
Ranolazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ranolazine. Management: Limit the ranolazine dose to a maximum of 500 mg twice daily in patients concurrently receiving moderate CYP3A4 inhibitors. Monitor for increased ranolazine effects and toxicities during concomitant use. Risk D: Consider Therapy Modification
Red Yeast Rice: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Red Yeast Rice. Risk C: Monitor
Regorafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Regorafenib. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Regorafenib. Risk C: Monitor
Repaglinide: Letermovir may increase serum concentration of Repaglinide. Management: Monitor for increased repaglinide effects/toxicities (ie, hypoglycemia) if combined with letermovir. When letermovir is coadministered with cyclosporine, the use of repaglinide is not recommended. Risk C: Monitor
Repotrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Repotrectinib. Risk X: Avoid
Ribociclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ribociclib. Risk C: Monitor
Rimegepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rimegepant. Management: If taking rimegepant for the acute treatment of migraine, avoid a second dose of rimegepant within 48 hours when used concomitantly with moderate CYP3A4 inhibitors. No dose adjustment needed if using rimegepant for prevention of episodic migraine. Risk D: Consider Therapy Modification
Rivaroxaban: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rivaroxaban. This warning is more specifically for drugs that are inhibitors of both CYP3A4 and P-glycoprotein. For erythromycin, refer to more specific erythromycin-rivaroxaban monograph recommendations. Risk C: Monitor
Roflumilast-Containing Products: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Roflumilast-Containing Products. Risk C: Monitor
Rosiglitazone: Letermovir may increase serum concentration of Rosiglitazone. Risk C: Monitor
Rupatadine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rupatadine. Risk C: Monitor
Ruxolitinib (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ruxolitinib (Systemic). Risk C: Monitor
Salmeterol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Salmeterol. Risk C: Monitor
Saquinavir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Saquinavir. Risk C: Monitor
SAXagliptin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SAXagliptin. Risk C: Monitor
Selpercatinib: CYP3A4 Inhibitors (Moderate) 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 80 mg twice/day, or from 160 mg twice/day to 120 mg twice/day. Risk D: Consider Therapy Modification
Selumetinib: CYP3A4 Inhibitors (Moderate) 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 (Moderate) may increase serum concentration of Sertindole. Risk X: Avoid
Sildenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sildenafil. Risk C: Monitor
Silodosin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Silodosin. Risk C: Monitor
Simeprevir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Simeprevir. Risk X: Avoid
Simvastatin: Letermovir may increase serum concentration of Simvastatin. Risk X: Avoid
Sirolimus (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sirolimus (Conventional). Management: Monitor for increased serum concentrations of sirolimus if combined with a moderate CYP3A4 inhibitor. Lower initial sirolimus doses or sirolimus dose reductions will likely be required. Risk D: Consider Therapy Modification
Sirolimus (Protein Bound): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sirolimus (Protein Bound). Management: Reduce the dose of protein bound sirolimus to 56 mg/m2 when used concomitantly with a moderate CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Solifenacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Solifenacin. Risk C: Monitor
Sonidegib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sonidegib. Management: Avoid concomitant use of sonidegib and moderate CYP3A4 inhibitors when possible. When concomitant use cannot be avoided, limit CYP3A4 inhibitor use to less than 14 days and monitor for sonidegib toxicity (particularly musculoskeletal adverse reactions). Risk D: Consider Therapy Modification
Sparsentan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sparsentan. Risk C: Monitor
SUFentanil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SUFentanil. Risk C: Monitor
SUNItinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SUNItinib. Risk C: Monitor
Suvorexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Suvorexant. Management: The recommended dose of suvorexant is 5 mg daily in patients receiving a moderate CYP3A4 inhibitor. The dose can be increased to 10 mg daily (maximum dose) if necessary for efficacy. Risk D: Consider Therapy Modification
Suzetrigine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Suzetrigine. Management: Reduce suzetrigine dose as follows: initiate with 100 mg for 1 dose; then 12 hours after first dose, give 50 mg every 12 hours for doses 2, 3, and 4; then 50 mg every 24 hours for dose 5 and thereafter. Risk D: Consider Therapy Modification
Tacrolimus (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tacrolimus (Systemic). Risk C: Monitor
Tacrolimus (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tacrolimus (Topical). Risk C: Monitor
Tadalafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tadalafil. Risk C: Monitor
Tamsulosin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tamsulosin. Risk C: Monitor
Tazemetostat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tazemetostat. Management: Avoid when possible. If combined, reduce tazemetostat dose from 800 mg twice daily to 400 mg twice daily, from 600 mg twice daily to 400 mg in AM and 200 mg in PM, or from 400 mg twice daily to 200 mg twice daily. Risk D: Consider Therapy Modification
Temsirolimus: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Temsirolimus. Specifically, concentrations of sirolimus may be increased. Risk C: Monitor
Teriflunomide: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tetrahydrocannabinol and Cannabidiol. Risk C: Monitor
Tetrahydrocannabinol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tetrahydrocannabinol. Risk C: Monitor
Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tezacaftor and Ivacaftor. Management: If combined with moderate CYP3A4 inhibitors, give tezacaftor/ivacaftor in the morning, every other day; give ivacaftor in the morning, every other day on alternate days. Tezacaftor/ivacaftor dose depends on age and weight; see full Lexi-Interact monograph Risk D: Consider Therapy Modification
Thioridazine: May decrease therapeutic effects of Letermovir. Risk X: Avoid
Thiotepa: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Thiotepa. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Thiotepa. Risk C: Monitor
Ticagrelor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ticagrelor. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Ticagrelor. Risk C: Monitor
Tilidine: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Tilidine. CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tilidine. Risk C: Monitor
Tofacitinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tofacitinib. Risk C: Monitor
Tolterodine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tolterodine. Risk C: Monitor
Tolvaptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tolvaptan. Management: Avoid this combination with Samsca brand of tolvaptan. Reduce dose for Jynarque brand: 90 mg AM and 30 mg PM, reduce to 45 mg AM and 15 mg PM; 60 mg AM and 30 mg PM, reduce to 30 mg AM and 15 mg PM; 45 mg AM and 15 mg PM, reduce to 15 mg AM and PM. Risk D: Consider Therapy Modification
Toremifene: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Toremifene. Risk C: Monitor
Trabectedin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Trabectedin. Risk C: Monitor
TraMADol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of TraMADol. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of TraMADol. Risk C: Monitor
TraZODone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of TraZODone. Risk C: Monitor
Tretinoin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tretinoin (Systemic). Risk C: Monitor
Triamcinolone (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Triamcinolone (Systemic). Risk C: Monitor
Triazolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Triazolam. Management: Consider triazolam dose reduction in patients receiving concomitant moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Trofinetide: May increase serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates (Clinically Relevant with Inhibitors). Management: Avoid concurrent use with OATP1B1/1B3 substrates for which small changes in exposure may be associated with serious toxicities. Monitor for evidence of an altered response to any OATP1B1/1B3 substrate if used together with trofinetide. Risk D: Consider Therapy Modification
Ubrogepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ubrogepant. Management: Use an initial ubrogepant dose of 50 mg and avoid a second dose for 24 hours when used with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Udenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Udenafil. Risk C: Monitor
UGT1A1 Inducers: May decrease serum concentration of Letermovir. Risk X: Avoid
Valbenazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Valbenazine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Valbenazine. Risk C: Monitor
Vamorolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vamorolone. Risk C: Monitor
Vanzacaftor, Tezacaftor, and Deutivacaftor: CYP3A4 Inhibitors (Moderate) 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: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vardenafil. Management: Limit Levitra (vardenafil) dose to a single 5 mg dose within a 24-hour period if combined with moderate CYP3A4 inhibitors. Avoid concomitant use of Staxyn (vardenafil) and moderate CYP3A4 inhibitors. Combined use is contraindicated outside of the US. Risk D: Consider Therapy Modification
Vemurafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vemurafenib. Risk C: Monitor
Venetoclax: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Venetoclax. Management: Reduce the venetoclax dose by at least 50% in patients requiring concomitant treatment with moderate CYP3A4 inhibitors. Resume the previous venetoclax dose 2 to 3 days after discontinuation of moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Verapamil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Verapamil. Risk C: Monitor
Vilazodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vilazodone. Risk C: Monitor
VinBLAStine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of VinBLAStine. Risk C: Monitor
VinCRIStine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of VinCRIStine. Risk C: Monitor
Vindesine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vindesine. Risk C: Monitor
Vinflunine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vinflunine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Vinflunine. Risk C: Monitor
Voclosporin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Voclosporin. Management: Decrease the voclosporin dose to 15.8 mg in the morning and 7.9 mg in the evening when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Vorapaxar: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vorapaxar. Risk C: Monitor
Voriconazole: Letermovir may decrease serum concentration of Voriconazole. Management: If concomitant administration of voriconazole with letermovir cannot be avoided, monitor for reduced voriconazole serum concentrations and efficacy. Risk D: Consider Therapy Modification
Warfarin: Letermovir may decrease serum concentration of Warfarin. Risk C: Monitor
Zanubrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zanubrutinib. Management: Decrease the zanubrutinib dose to 80 mg twice daily during coadministration with a moderate CYP3A4 inhibitor. Further dose adjustments may be required for zanubrutinib toxicities, refer to prescribing information for details. Risk D: Consider Therapy Modification
Zopiclone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zopiclone. Risk C: Monitor
Zuranolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zuranolone. Risk C: Monitor
Adverse events were observed in some animal reproduction studies.
Monitor for cytomegalovirus (CMV) reactivation; serum creatinine (especially in patients with CrCl <50 mL/minute [due to potential accumulation of IV vehicle hydroxypropyl betadex]).
Letermovir inhibits cytomegalovirus (CMV) replication by targeting the CMV DNA terminase complex (pUL51, pUL56, pUL89), which is required for viral DNA processing and packaging. Letermovir affects production of genome unit lengths and alters virion maturation.
Distribution: IV: 45.5 L.
Protein binding: 99%.
Metabolism: Hepatic via UGT1A1/1A3 (minor).
Bioavailability: Oral: Healthy subjects (without cyclosporine): 94%; hematopoietic cell transplant (HCT) recipients (480 mg orally once daily without cyclosporine): 35%; HCT recipients (240 mg orally once daily with cyclosporine): 85%; kidney transplant recipients (480 mg once daily without cyclosporine): 56%.
Half-life elimination: 12 hours.
Time to peak: 1.5 to 3 hours.
Excretion: Feces: 93% (70% as unchanged drug); urine: <2%.
Altered kidney function: Letermovir AUC was approximately 1.9- and 1.4-fold higher in subjects with moderate (eGFR 30 to 59 mL/minute/1.73 m2) and severe (eGFR <30 mL/minute/1.73 m2) renal impairment, respectively, compared to healthy subjects (eGFR ≥90 mL/minute/1.73 m2) (Kropeit 2017b).
Post kidney transplant: AUC was approximately 1.1-, 1.3-, and 1.4-fold higher in subjects with mild (CrCl 60 mL/minute to <90 mL/minute), moderate (CrCl 30 mL/minute to <60 mL/minute), and severe (CrCl 15 mL/minute to <30 mL/minute) renal impairment, respectively (compared to subjects with CrCl ≥90 mL/minute).
Hepatic function impairment: Letermovir AUC was approximately 1.6- and 3.8-fold higher in female subjects with moderate (Child-Pugh class B) and severe (Child-Pugh class C) hepatic impairment, respectively, compared to healthy female subjects (Kropeit 2017a).