Interactions between thioridazine-hydrochloride(thioridazine) and Amitriptyline (amitriptyline)
amitriptyline and thioridazine (Major Drug-Drug)
CONTRAINDICATED: Coadministration of thioridazine with another phenothiazine or a tricyclic antidepressant (TCA) may result in elevated plasma concentrations of both drugs. Most phenothiazines and TCAs have been found to undergo metabolism by CYP450 2D6, thus competitive inhibition of the enzyme may occur when more than one of these agents are administered. The possibility of an increased risk of serious adverse effects such as central nervous system depression, hypotension, and arrhythmia should be considered. In addition, these agents individually can cause prolongation of the QT interval, thus concomitant administration may result in elevated risk of ventricular arrhythmias including ventricular tachycardia and torsade de pointes.
MANAGEMENT: The use of thioridazine with drugs that can inhibit CYP450 2D6 and/or prolong the QT interval is considered contraindicated.
