CriticalClass III antiarrhythmics (Vaughan Williams)×First-generation antipsychotic, diphenylbutylpiperidine derivative
Updated · Methodology
Mechanism
Amiodarone is a moderate CYP3A4 inhibitor and the strongest clinical QT prolonger. Double torsades risk. FDA Orap Section 4 + additive QT effect.
Symptoms
QT prolongation (amiodarone itself extends 30–50 ms), syncope, torsades de pointes.
Management
Combination contraindicated. For atrial fibrillation in a pimozide patient, use a beta-blocker for rate control or catheter ablation.
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: Pimozide tablet (Par Health USA, LLC) – Prescribing Information (2011)– FDA Orap label, Section 4 Contraindications; DailyMed setid 70b079e2-a1f7-4a93-8685-d60a4d7c1280
- AEMPS: Ficha técnica: Amiodarona (nº registro 81291), sección 4.5 (2022)– AEMPS, CIMA, nº registro 81291, revisión 06/2022, sección 4.5