Encorafenib and Paritaprevir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Paritaprevir
No brand names on recordEncorafenib
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
Increased encorafenib exposure, an increased risk of encorafenib-related adverse events, altered (increased/reduced) paritaprevir exposure and an increased risk of paritaprevir-related toxicities
Interaction Deep Dive
Avoid concomitant administration of encorafenib with paritaprevir (a strong CYP3A4 inhibitor and a substrate of CYP3A4, OATP1B1 and OATP1B3) as it may increase encorafenib/paritaprevir exposure and may also increase risk of encorafenib/paritaprevir-related adverse reactions. Concomitant use may also reduce paritaprevir exposure and may reduce efficacy of paritaprevir. If coadministration cannot be avoided, reduce the encorafenib dose. If the current encorafenib dose is 450 mg/day, reduce to 150 mg/day and if it is 300, 225, or 150 mg/day, reduce to 75 mg/day. Note that encorafenib exposure with 75 mg/day when coadministered with a strong CYP3A4 inhibitor is expected to be higher than at the 150 mg/day dosage in the absence of a CYP3A4 inhibitor and similar to exposure at the 225 mg/day dosage in the absence of a CYP3A4 inhibitor. Monitor patients closely for adverse reactions and use clinical judgement when using encorafenib 150 mg/day with strong CYP3A4 inhibitors. After the inhibitor has been discontinued for 3 to 5 elimination half-lives, resume the encorafenib dose that was taken prior to initiating paritaprevir. In a drug interaction study, coadministration of posaconazole (a strong CYP3A4 inhibitor) with encorafenib increased the AUC of encorafenib by 3-fold and increased the Cmax by 68% following a single dose of encorafenib 50 mg (0.1 times the usual dose)1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated encorafenib metabolism; inhibition of OATP1B1-mediated efflux transport by encorafenib; inhibition of OATP1B3-mediated efflux transport by encorafenib; induction of CYP3A4-mediated metabolism of paritaprevir
Literature reports
3 reports — tap to read
a) In a drug interaction study, coadministration of posaconazole (a strong CYP3A4 inhibitor) with encorafenib increased the AUC of encorafenib by 3-fold and increased the Cmax by 68% following a single dose of encorafenib 50 mg (0.1 times the usual dose) 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.
c) 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.
Common questions
Can I take Encorafenib and Paritaprevir together?
Increased encorafenib exposure, an increased risk of encorafenib-related adverse events, altered (increased/reduced) paritaprevir exposure and an increased risk of paritaprevir-related toxicities Always confirm with your pharmacist or prescriber before making any change.
How serious is the Encorafenib and Paritaprevir 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 Paritaprevir 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: BRAFTOVI(R) oral capsules, encorafenib oral capsules. Array BioPharma Inc (per FDA), Boulder, CO, 2024. DailyMed
Keep reading about Paritaprevir
Keep reading about Encorafenib
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