Calcium antagonists

These drugs are called calcium antagonists (also calcium channel blockers) because they exert their effect on the muscle cells in arteries. They block the cells from being able to use calcium which is they need when contracting to make the artery narrower.

The result is more blood flow to the heart and less resistance from arteries around the body.

There are two basic classes - dihydropyridines and nondihydropyridines - however and they have somewhat different properties.

The latter have quite a slowing effect on the heart and reduce its force of pumping and should therefore not be used in patients with heart failure, nor combined with beta blockers. Examples are diltiazem and verapamil.

Dihydropyridines, especially the newer ones (amlodipine, lacidipine) have no effect on the heart. However Calcium channel blockers are good for treating patients who also have angina.

They can cause flushing, headaches and swollen ankles. Generally however they are very popular and well tolerated.

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This page was last modified on : May 16, 2011.