Ventricular premature contractions associated with iloperidone

Typical and atypical antipsychotic drugs are known to block potassium repolarization channels, prolong the QTc interval, and thereby predispose to ventricular tachyarrhythmias. We report a young male schizophrenic patient who experienced clinically significant and symptomatically distressing ventricular premature contractions (VPCs) in close temporal relation with iloperidone (8-16 mg/day) treatment; there had been no VPCs with prior exposure to risperidone, trihexyphenidyl, and olanzapine, nor with subsequent exposure to asenapine. We hypothesize that the VPCs may have been triggered by an alpha 2c receptor blockade-mediated cardiostimulatory action associated with iloperidone.