Drotaverine (Drotaverin) is an isoquinoline-based PDE4-selective phosphodiesterase (PDE) inhibitor and an L-type voltage-dependent (voltage-operated) calcium channel (L-VDCC or L-VOCC) blocker that exhibits in vivo antispasmodic efficacy without anticholinergic effects.
It is a benzylisoquinoline derivative. Drotaverine acts as a smooth muscle relaxant.