Calcium channel blockers prevent calcium from entering cells of the heart and blood vessel walls, resulting in lower blood pressure. Calcium channel blockers, also called calcium antagonists, relax and widen blood vessels by affecting the muscle cells in the arterial walls.
Some calcium channel blockers have the added benefit of slowing your heart rate, which can further reduce blood pressure, relieve chest pain (angina) and control an irregular heartbeat.
Examples of calcium channel blockers
Some calcium channel blockers are available in short-acting and long-acting forms. Short-acting medications work quickly, but their effects last only a few hours. Long-acting medications are slowly released to provide a longer lasting effect.
Several calcium channel blockers are available. Which one is best for you depends on your health and the condition being treated.
Examples of calcium channel blockers include:
- Amlodipine (Norvasc)
- Diltiazem (Cardizem, Tiazac, others)
- Nifedipine (Adalat CC, Afeditab CR, Procardia)
- Nisoldipine (Sular)
- Verapamil (Calan, Verelan)
In some cases, your doctor might prescribe a calcium channel blocker with other high blood pressure medications or with cholesterol-lowering drugs such as statins.
Uses for calcium channel blockers
Doctors prescribe calcium channel blockers to prevent, treat or improve symptoms in a variety of conditions, such as:
- High blood pressure
- Coronary artery disease
- Chest pain (angina)
- Irregular heartbeats (arrhythmia)
- Some circulatory conditions, such as Raynaud's disease
For people of African heritage and older people, calcium channel blockers might be more effective than other blood pressure medications, such as beta blockers, angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers.
Side effects and cautions
Side effects of calcium channel blockers may include:
- Swelling in the feet and lower legs
Certain calcium channel blockers interact with grapefruit products.