Calcium channel blocker medicines prevent calcium from entering muscle cells and blood vessels. As a result, blood vessels relax, which slows the heart rate and increases blood flow to the heart muscle while reducing blood pressure.
Calcium channel blockers are used to treat heart conditions, including high blood pressure, angina caused by coronary artery disease, and fast or irregular heart rhythms. They are also used to treat severe headaches.
WebMD Medical Reference from Healthwise