MajorClass III antiarrhythmics (Vaughan Williams)×Selective serotonin reuptake inhibitors (SSRIs)
Updated · Methodology
Mechanism
Both drugs prolong QT. Amiodarone strongly (via IKr potassium channel block), sertraline dose-dependently and more weakly. Effects add up, especially at high sertraline doses (>100 mg/day) and risk factors: hypokalaemia, female sex, older age.
Symptoms
QT prolongation on ECG. Clinically: dizziness, syncope, palpitations. Severe cases progress to polymorphic ventricular tachycardia (torsades de pointes) with risk of ventricular fibrillation and sudden cardiac death. Risk is higher with hypokalaemia, hypomagnesaemia, bradycardia, and ischaemic heart disease.
Management
The combination is acceptable at low sertraline doses (≤100 mg/day) and normal potassium and magnesium. ECG before start and at 2 weeks. Alternative antidepressants with minimal QT effect: mirtazapine or agomelatine.
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.
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Sources
- Lexicomp: Lexicomp Drug Interactions (2024)– Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- Pharmaceutical Press: Stockley's Drug Interactions, 12th edition (2024)– Preston CL (ed.). Stockley's Drug Interactions. 12th ed. London: Pharmaceutical Press; 2024
- AEMPS: Ficha técnica: Sertralina (nº registro 66057), sección 4.5 (2025)– AEMPS, CIMA, nº registro 66057, sección 4.5