Dexverapamil is a 2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl](methyl)amino}-2-(propan-2-yl)pentanenitrile with R configuration. It competitively inhibits the multidrug resistance efflux pump P-glycoprotein (MDR-1, EC 3.6.3.44), enhancing the efficacy of antineoplastic drugs inactivated by MDR-1. Dexverapamil has lower calcium antagonistic activity and toxicity compared to racemic verapamil. It functions as an EC 3.6.3.44 (xenobiotic-transporting ATPase) inhibitor and is the conjugate base of dexverapamil(1+). It is the enantiomer of (S)-verapamil.
