DRUGS TO COMBAT HEART FAILURE: NITRITES AND NITRATES

The pain of angina is caused by some defect in the coronary arteries, those arteries that supply blood to the heart. Thus a substance which will dilate blood-vessels and allow blood to flow more freely will help to relieve anginal pain.

This is precisely how nitrite and nitrate drugs work. The most important of these drugs is glyceryl trinitrate. Actually, this compound is doubly interesting because most people know it by another name and in a quite different context: it is nitroglycerine, that highly explosive basis of dynamite. Rest assured, though, thatnitroglicerine as a medicine comes to you in perfectly harmless half-milligram tablets. It has a long history of success in helping angina sufferers, stretching back to the beginning of this century.

Nitrates act on the smooth muscle of the blood vessels. There, within the inner walls, they cause the muscle fibres to relax and the vessels to dilate. Blood-flow is improved, blood-pressure temporarily reduced and, within a very short space of time, pain relieved.

Unfortunately, there may be side-effects with the large doses sometimes needed to reduce the severity of angina. Headaches and flushing occur - indeed, head pain is often difficult to avoid. High doses can also give rise to faintness if the sufferer remains on his or her feet.

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CARDIO & BLOOD