Encorafenib and Maribavir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Maribavir
Encorafenib
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced maribavir exposure and reduced efficacy of maribavir
Interaction Deep Dive
Coadministration of maribavir with a strong CYP3A4 inducer is not recommended due to reduced maribavir exposure and potential loss of efficacy. Coadministration of rifAMPin (a strong CYP3A4 inducer) and maribavir (a CYP3A4 substrate) resulted in significantly decreased maribavir exposure. Mean maribavir AUC and Cmax decreased by 60% and 39%, respectively, after administration of rifAMPin 600 mg once daily with maribavir 400 mg twice daily (N=14). Based on a population pharmacokinetic model (N=200) maribavir AUC and Cmax increased by 40% and 53%, respectively, when administered at a dose of 800 mg twice daily with carBAMazepine 400 mg once daily (a strong CYP3A4 inducer), compared with a dose of maribavir 400 mg twice daily without carBAMazepine. Also, maribavir (N=200) AUC and Cmax increased by 70% and 105%, respectively, when administered at a dose of 1200 mg twice daily with phenytoin 300 mg once daily (a strong CYP3A4 inducer), compared with a dose of maribavir 400 mg twice daily without phenytoin1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of maribavir
Literature reports
2 reports — tap to read
a) Based on a population pharmacokinetic model (N=200) maribavir AUC and Cmax increased by 40% and 53%, respectively, when administered at a dose of 800 mg twice daily with carBAMazepine 400 mg once daily (a strong CYP3A4 inducer), compared with a dose of maribavir 400 mg twice daily without carBAMazepine. Also, maribavir (N=200) AUC and Cmax increased by 70% and 105%, respectively, when administered at a dose of 1200 mg twice daily with phenytoin 300 mg once daily (a strong CYP3A4 inducer), compared with a dose of maribavir 400 mg twice daily without phenytoin 1.
b) Coadministration of rifAMPin (a strong CYP3A4 inducer) and maribavir (a CYP3A4 substrate) resulted in significantly decreased maribavir exposure. Mean maribavir AUC and Cmax decreased by 60% and 39%, respectively, after administration of rifAMPin 600 mg once daily with maribavir 400 mg twice daily (N=14) 1.
Common questions
Can I take Encorafenib and Maribavir together?
Reduced maribavir exposure and reduced efficacy of maribavir Always confirm with your pharmacist or prescriber before making any change.
How serious is the Encorafenib and Maribavir interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Encorafenib or Maribavir need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: LIVTENCITY® oral tablets, maribavir oral tablets. Takeda Pharmaceuticals America Inc (per FDA), Cambridge, MA, 2025. DailyMed
Keep reading about Maribavir
Keep reading about Encorafenib
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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