Other names: calcium antagonists, calcium channel antagonists, calcium channel blockers, CCB
  Calcium channel blocking agents restrict the amount of calcium entering cardiac and smooth muscle cells by blocking voltage-gated calcium channels. This causes blood vessels to relax and widen (vasodilate), improves oxygen supply to the heart, and lowers blood pressure. Some calcium channel blockers also slow the heart rate.
  Calcium channel blocking agents are used to treat conditions of the heart or blood vessels including high blood pressure, angina, arrhythmias, and circulatory disorders.