calcium-channel blocker

Any of a group of drugs that interfere with the entry of calcium into smooth muscle cells. They influence the cells of the heart muscle and conducting tissue, reducing the strength of contraction and slowing the beat, and also the cells within the walls of the arteries, causing vasodilation. They are used to treat angina, hypertension and cardiac arrhythmias. One drug in the group, nimodipine, is used to prevent spasm of the cerebral arteries following subarachnoid haemorrhage.