About Nimodipine A dihydropyridine calcium channel blocker, Treatment of neurologic defects associated with subarachnoid hemorrhage. Mechanism of Action of Nimodipine Nimodipine is a Ca channel blocker. It exerts its actions through blocking the influx of Ca ions through voltage gated L-type Ca channels to the vascular smooth muscle and resulting in relaxation of vascular smooth muscles. Being highly lipophilic it has greater action on the cerebral vessels. Indications for Nimodipine 1. Prevention of cerebral vasospasm and resultant ischemia following subarachnoid haemorrhage. Interactions for Nimodipine Other calcium channel blockers: Increase its effect. Phenytoin & caffeine: Increased toxicity of these drugs due to decreased hepatic metabolism.