Abemaciclib and Ketoconazole: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Abemaciclib and Ketoconazole unless specifically directed by your doctor.
How Abemaciclib interacts with Ketoconazole
Ketoconazole strongly inhibits CYP3A4-mediated metabolism of abemaciclib, increasing exposure 16-fold and risk of severe neutropenia, diarrhea, and hepatotoxicity.
What you should do
Avoid concomitant strong CYP3A4 inhibitors; if unavoidable, reduce abemaciclib dose to 50 mg twice daily.
Key facts
Severity
Major — avoid combination
Mechanism
Ketoconazole strongly inhibits CYP3A4-mediated metabolism of abemaciclib, increasing exposure 16-fold and risk of severe...
Action
Avoid concomitant strong CYP3A4 inhibitors; if unavoidable, reduce abemaciclib dose to 50 mg twice daily.
Frequently asked questions
Can I take Abemaciclib and Ketoconazole together?
No — this combination should generally be avoided. Avoid concomitant strong CYP3A4 inhibitors; if unavoidable, reduce abemaciclib dose to 50 mg twice daily.
What is the severity of this interaction?
The interaction between Abemaciclib and Ketoconazole is classified as Major — avoid combination. Ketoconazole strongly inhibits CYP3A4-mediated metabolism of abemaciclib, increasing exposure 16-fold and risk of severe neutropenia, diarrhea, and hepatotoxicity.
What should I do if I'm prescribed both?
Avoid concomitant strong CYP3A4 inhibitors; if unavoidable, reduce abemaciclib dose to 50 mg twice daily. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.