Calcium channel blockers are medications used to relax and broaden blood vessels in order to facilitate blood flow and cause high blood pressure to be normalized. Certain calcium channel blockers such as verapamil and diltiazem also decrease heart rate and have an effect on the heart's pumping function.

These medications can be used in conjunction with a beta-blocker, diuretic or other such medications, as well as by themselves. They are more useful when treating African-Americans, the elderly, and people who face difficulties with lowering their consumption of sodium. Calcium channel blockers can also control symptoms of angina in hypertensive individuals who suffer from coronary artery diseases, and are often prescribed in such cases.

Calcium channel blockers help to decrease blood pressure and relaxing coronary arteries, which are responsible for the passage of blood to the heart.

Calcium channel blockers, like most medications, have a number of side-effects, such as lethargy, headaches, facial flushing, water retentiveness in the legs as well as a detectable increase in heart rate. In cases of verapamil and diltiazem, however, the heart rate actually decreases, and constipation also occurs as a side-effect.

Calcium channel blockers may interfere with other medication, so they should not be used without a doctor's recommendation.