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Interacting Drugs

OBJECT DRUGS

PRECIPITANT DRUGS

Drugs That Inhibit CYP2D6 and Prolong the QT Interval:


Comment:

Thioridazine can prolong the QT interval in a dose-dependent manner. Drugs that inhibit the cytochrome P450 isozymes involved in thioridazine metabolism (primarily CYP2D6) may increase the risk of ventricular arrhythmias such as torsades de pointes. Amiodarone and quinidine are strong inhibitors of CYP2D6, and also individually prolong the QT interval. Hence, the risk of serious arrhythmias is likely to be substantially increased. The product information for thioridazine states that it is contraindicated with known CYP2D6 inhibitors or drugs that increase the QT interval.


Class 1: Avoid Combination