Nitrates

Nitrates work by dilating (opening up) blood vessels in the body.

Acute angina attacks are treated by glyceryl trinitrate (GTN) under the tongue in either spray or tablet form.

It should be used as a prevention of angina, before planned exercise, and in stress, as well as to treat it.

Long acting nitrates are taken in the form of tablets, which are taken orally and can have a good effect. Care has to be taken that tolerance to the drug does not occur and a nitrate-free period must occur in the 24-hour period (i.e. at night for 6-8 hours). If nighttime angina occurs the nitrate tablets should be left off for several consecutive hours in the day.

Nitrates can also be presented in patch (transdermal) form.

Medication used is Isosorbide mononitrate or Isosorbide dinitrate.

Side effects

The main side effect is throbbing, severe headaches due to dilatation of blood vessels (including the coronary arteries).

Headaches and flushes tend to reduce after a few days with continued use. With the use of tablets, the tablet should be spat out as soon as the effect is reached.

Flushing and dizziness are uncommon side effects and if this is known to occur, are relieved by sitting down; the patient should have sufficient warning to do this. This tends to reduce in time, as the person gets used to the medication