Drug Interaction Report

Bosentan and Encorafenib: Interaction Details

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Bosentan

No brand names on record
+

Encorafenib

Braftovi Braftovi®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 67 documented Bosentan interactions, 53 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Reduced encorafenib exposure, reduced efficacy of encorafenib, increased bosentan exposure and increased risk of bosentan-related toxicities

Interaction Deep Dive

Avoid concomitant administration of encorafenib (a CYP3A4 substrate and an inhibitor of OATP1B1 and OATP1B3) with bosentan (a moderate CYP3A4 inducer and a substrate of OATP1B1 and OATP1B3) as it may reduce encorafenib exposure and may reduce efficacy of encorafenib. It may also increase exposure of bosentan and increase its toxicity. If use is necessary, monitor for signs and symptoms of increased bosentan exposure and consider adjusting the bosentan dose if needed. In a drug interaction study, repeated doses of encorafenib 450 mg once daily and binimetinib 45 mg twice daily with a single dose of rosuvastatin (a sensitive substrate of OATP1B1 and OATP1B3) increased rosuvastatin Cmax by 2.7-fold and AUC by 1.6-fold1.

Why it happens (mechanism)

Induction of CYP3A4-mediated encorafenib metabolism; inhibition of OATP1B1-mediated efflux transport of bosentan; inhibition of OATP1B3-mediated efflux transport of bosentan

Literature reports

2 reports — tap to read

a) In a drug interaction study, repeated doses of encorafenib 450 mg once daily and binimetinib 45 mg twice daily with a single dose of rosuvastatin (a sensitive substrate of OATP1B1 and OATP1B3) increased rosuvastatin Cmax by 2.7-fold and AUC by 1.6-fold 1.

b) In a drug interaction study, repeat dose administration of encorafenib 450 mg once daily and binimetinib 45 mg twice daily with a single dose of midazolam 2 mg, a sensitive CYP3A4 substrate, decreased midazolam AUC by 82% and Cmax by 74% relative to midazolam 2 mg alone 1.

Common questions

Can I take Bosentan and Encorafenib together?

Reduced encorafenib exposure, reduced efficacy of encorafenib, increased bosentan exposure and increased risk of bosentan-related toxicities Always confirm with your pharmacist or prescriber before making any change.

How serious is the Bosentan and Encorafenib 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 Bosentan or Encorafenib 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)

  1. Product Information: BRAFTOVI(R) oral capsules, encorafenib oral capsules. Array BioPharma Inc (per FDA), Boulder, CO, 2024. DailyMed
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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.