calcium-channel blocker

views updated

calcium-channel blocker (calcium antagonist) n. a drug that inhibits the influx of calcium ions into cardiac and smooth-muscle cells; it therefore reduces the strength of heart-muscle contraction, reduces conduction of impulses in the heart, and causes vasodilatation. Calcium-channel blockers, which include amlodipine, diltiazem, nicardepine, nifedipine, and verapamil, are used to treat angina and high blood pressure.