Updated June 10, 2015.

Definition:

These medications works by preventing the arteries from contracting. All muscles in the body need calcium to contract. Calcium channel blockers keep calcium from entering into the muscles that control the arteries. This keeps the arteries from contracting -- in other words the medicine blocks the calcium channel of the artery muscles. The larger arteries means lower blood pressure. The calcium blockers only work in the bloodstream and do not effect the calcium in your bones.

Types of Calcium Channel Blockers

There are two main types of calcium channel blockers: Short-acting and Long-acting. The short-acting calcium channel blockers work very quickly, but also wear off very quickly. The long-acting calcium channel blockers take long to work, but also have a longer effect.

When are they Used?

Calcium Channel Blockers are not considered as effective as other blood pressure medications. They are generally not used in a situation where heart failure or heart attack risk is high because they will also effect the heart muscle. They are often used in people with low renin, a hormone produced by the kidneys.

Side Effects

Side effects include headaches, feeling flush, swelling in the legs and dizziness.

source: MDConsult

Also Known As: Calcium Antagonists, Calcium Channel Blocking Agents