Methadone and Pimozide: interaction and safety
This source-based reference is not a personal treatment recommendation. The relevance and management of an interaction depend on the exact products, route, dose and clinical situation.
Interaction mechanism
Additive central nervous system and respiratory depression; Additive potential for QT prolongation and ventricular arrhythmia.
Clinical significance and safety
The listed product includes pimozide; its antipsychotic component can add to methadone effects, causing marked sedation, low blood pressure and potentially fatal breathing suppression. This rhythm-affecting medicine can add to methadone-related QT prolongation; fainting or a new irregular heartbeat requires urgent assessment. A prescriber or pharmacist should review the combination; do not independently stop, start or change either medicine.
Using this information
This is a source-based reference record, not a recommendation to combine, stop or change medicines. A missing interaction record does not establish safe use. A qualified healthcare professional should consider the exact products, doses, other medicines and individual health circumstances.