CriticalClass III antiarrhythmics (Vaughan Williams)×First-generation antipsychotic, aliphatic-side-chain phenothiazine
Updated · Methodology
Mechanism
Dual QT prolongation, additive hypotension (chlorpromazine alpha-1 block).
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
Combination contraindicated.
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: Thorazine (chlorpromazine) prescribing information (2014)– FDA Thorazine label
- AEMPS: Ficha técnica: Amiodarona (nº registro 81291), sección 4.5 (2022)– AEMPS, CIMA, nº registro 81291, revisión 06/2022, sección 4.5