Ketoconazole and Quinidine: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Ketoconazole and Quinidine unless specifically directed by your doctor.
How Ketoconazole interacts with Quinidine
Ketoconazole inhibits CYP3A4 and P-glycoprotein, both involved in quinidine metabolism and elimination, increasing quinidine exposure with risk of QT prolongation and torsades.
What you should do
Avoid combination. If unavoidable, reduce quinidine dose, monitor ECG, and correct electrolytes; consider alternative azole (fluconazole at low dose less likely to interact).
Key facts
Severity
Major — avoid combination
Mechanism
Ketoconazole inhibits CYP3A4 and P-glycoprotein, both involved in quinidine metabolism and elimination, increasing quini...
Action
Avoid combination. If unavoidable, reduce quinidine dose, monitor ECG, and correct electrolytes; consider alternative az...
Frequently asked questions
Can I take Ketoconazole and Quinidine together?
No — this combination should generally be avoided. Avoid combination. If unavoidable, reduce quinidine dose, monitor ECG, and correct electrolytes; consider alternative azole (fluconazole at low dose less likely to interact).
What is the severity of this interaction?
The interaction between Ketoconazole and Quinidine is classified as Major — avoid combination. Ketoconazole inhibits CYP3A4 and P-glycoprotein, both involved in quinidine metabolism and elimination, increasing quinidine exposure with risk of QT prolongation and torsades.
What should I do if I'm prescribed both?
Avoid combination. If unavoidable, reduce quinidine dose, monitor ECG, and correct electrolytes; consider alternative azole (fluconazole at low dose less likely to interact). Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.