Ketoconazole and Quetiapine: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Ketoconazole and Quetiapine unless specifically directed by your doctor.
How Ketoconazole interacts with Quetiapine
Ketoconazole strongly inhibits CYP3A4, the primary pathway for quetiapine metabolism, increasing quetiapine AUC 6- to 8-fold with QT prolongation and sedation risk.
What you should do
Avoid combination; if antifungal is required, use fluconazole or terbinafine and reduce quetiapine to one-sixth of usual dose if no alternative.
Key facts
Severity
Major — avoid combination
Mechanism
Ketoconazole strongly inhibits CYP3A4, the primary pathway for quetiapine metabolism, increasing quetiapine AUC 6- to 8-...
Action
Avoid combination; if antifungal is required, use fluconazole or terbinafine and reduce quetiapine to one-sixth of usual...
Frequently asked questions
Can I take Ketoconazole and Quetiapine together?
No — this combination should generally be avoided. Avoid combination; if antifungal is required, use fluconazole or terbinafine and reduce quetiapine to one-sixth of usual dose if no alternative.
What is the severity of this interaction?
The interaction between Ketoconazole and Quetiapine is classified as Major — avoid combination. Ketoconazole strongly inhibits CYP3A4, the primary pathway for quetiapine metabolism, increasing quetiapine AUC 6- to 8-fold with QT prolongation and sedation risk.
What should I do if I'm prescribed both?
Avoid combination; if antifungal is required, use fluconazole or terbinafine and reduce quetiapine to one-sixth of usual dose if no alternative. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.