MajorClass III antiarrhythmic×Selective serotonin reuptake inhibitors
Updated · Methodology
Mechanism
Fluoxetine blocks CYP2D6 (strongly) and CYP3A4 (moderately). Dronedarone plasma levels may rise. Additive QT risk.
Symptoms
QT prolongation on ECG. Dizziness, syncope, palpitations. Severe cases: polymorphic ventricular tachycardia (torsades de pointes). Risk is higher with hypokalaemia and hypomagnesaemia.
Management
Avoid the combination. Alternative antidepressants without CYP3A4/CYP2D6 inhibition: sertraline or escitalopram. Alternative antiarrhythmic: a beta-blocker for rate control.
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: Multaq (dronedarone) prescribing information (2020)– ; DailyMed setid 7fa41601-7fb5-4155-8e50-2ae903f0d2d6
- AEMPS: Ficha técnica: Fluoxetina (nº registro 63499), sección 4.5 (2026)– AEMPS, CIMA, nº registro 63499, revisión 10/2026, sección 4.5
- AEMPS: Ficha técnica: Dronedarona (nº registro 84320), sección 4.5 (2025)– AEMPS, CIMA, nº registro 84320, revisión 10/2025, sección 4.5