Calcium channel blockers are a class of medication that are commonly prescribed for high blood pressure and heart conditions. These medications work by blocking the flow of calcium into the heart and blood vessels, which helps to relax the muscles and improve blood flow. Some synonyms for calcium channel blockers include calcium antagonists, calcium ion channel blockers, and calcium entry blockers. These terms essentially describe the same class of medication, and can be used interchangeably. Calcium channel blockers are widely used in the treatment of cardiovascular disease, and are considered to be safe and effective medications with relatively few side effects.