efavirenz and Vascor Interactions

Interactions between efavirenz and Vascor (bepridil)

bepridil and efavirenz (Major Drug-Drug)

CONTRAINDICATED: Coadministration with efavirenz may increase the plasma concentrations of bepridil. The proposed mechanism is competitive inhibition of bepridil metabolism via CYP450 3A4. Bepridil is associated with dose-related prolongation of the QT interval in addition to the usual range of proarrhythmic effects characteristic of Class I antiarrhythmics, thus high plasma levels may increase the risk of ventricular arrhythmias including ventricular tachycardia, ventricular fibrillation, and torsade de pointes.

MANAGEMENT: The concomitant use of bepridil and efavirenz is considered contraindicated.