MajorClass III antiarrhythmics (Vaughan Williams)×Antifungals, triazole derivatives
Updated · Methodology
Mechanism
Fluconazole prolongs the QT interval on its own by blocking the cardiac Ikr potassium current. It is also a moderate CYP3A4 inhibitor, and amiodarone is partly cleared by CYP3A4, so, per the fluconazole label, the QT prolongation caused by amiodarone can be amplified. The risk is higher with high-dose fluconazole (800 mg a day).
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
ECG monitoring. If possible – terbinafine for superficial infections.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Diflucan (fluconazole) prescribing information (2014)– ; DailyMed setid f694c617-3383-416c-91b6-b94fda371204
- FDA: Pacerone (amiodarone hydrochloride) tablets – Prescribing Information (2025)– FDA, DailyMed SPL, Upsher-Smith Laboratories, раздел 7
- AEMPS: Ficha técnica Trangorex 200 mg comprimidos (amiodarona) (2022)– AEMPS, CIMA, nº registro 48048, revisión 01/2022, sección 4.5
- AEMPS: Ficha técnica Diflucan 200 mg cápsulas duras (fluconazol) (2024)– AEMPS, CIMA, nº registro 58803, revisión 02/2024, secciones 4.3, 4.4 y 4.5