Which medication is used to counter vasospasm by preventing calcium from entering smooth muscle cells?

The medication used to counter vasospasm by preventing calcium from entering smooth muscle cells is nimodipine. Nimodipine is a calcium channel blocker that is particularly effective in protecting against cerebral vasospasm, often seen after subarachnoid hemorrhage. By inhibiting the influx of calcium into vascular smooth muscle cells, nimodipine causes relaxation and dilation of blood vessels, thereby improving blood flow and reducing the risk of ischemia.

This mechanism of action makes nimodipine particularly well-suited for conditions involving vasospasm, as it specifically targets pathways that lead to vascular constriction. The medication is invaluable in acute care settings where prompt intervention is necessary to prevent or mitigate complications related to cerebral vasospasm following hemorrhagic strokes. Its selective action on the central nervous system’s vasculature differentiates it from other calcium channel blockers, which may not have the same efficacy in this specific context.