Encorafenib and Zongertinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Encorafenib
Zongertinib
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 zongertinib exposure and reduced efficacy of zongertinib
Interaction Deep Dive
Avoid concomitant use of zongertinib (CYP3A substrate) with strong CYP3A inducers as it may reduce zongertinib exposure, which may reduce efficacy of zongertinib. If concomitant use cannot be avoided, increase the zongertinib dose based on body weight: If less than 90 kg, increase the dose from 120 mg to 240 mg; If more than or equal to 90 kg, increase the dose from 180 mg to 360 mg. After discontinuing a CYP3A inducer, resume the zongertinib dose (7 to 14 days after discontinuing the CYP3A inducer) that was taken prior to initiating the CYP3A inducer. In the drug interaction studies, coadministration of zongertinib carBAMazepine (strong CYP3A inducer) 600 mg once daily for 7 days, resulted in decreased AUC and Cmax by 63% and 43%, respectively1.
Why it happens (mechanism)
Induction of CYP3A-mediated metabolism of zongertinib
Literature reports
1 report — tap to read
a) In the drug interaction studies, coadministration of zongertinib carBAMazepine (strong CYP3A inducer) 600 mg once daily for 7 days, resulted in decreased AUC and Cmax by 63% and 43%, respectively 1.
Common questions
Can I take Encorafenib and Zongertinib together?
Reduced zongertinib exposure and reduced efficacy of zongertinib Always confirm with your pharmacist or prescriber before making any change.
How serious is the Encorafenib and Zongertinib 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 Zongertinib 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: HERNEXEOS(R) oral tablets, zongertinib oral tablets. Boehringer Ingelheim Pharmaceuticals, Inc (per FDA), Ridgefield, CT, 2025. DailyMed
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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