Nitrates

How they work

Nitrates are cardiac drugs that break down to produce Nitrous Oxide (NO), which is a potent vasodilator. This means they are very good at widening coronary arteries, relieving angina.

Common types and dose

Two main types:

• Glyceryl trinitrate short acting, and well known as the GTN spray. Patients take a puff when they get chest pain. In the case of unstable angina, GTN will no longer relieve the pain.
• Isosorbide Dinitrate longer acting, used to relieve pain, or taken daily in order to provide prophylaxis again angina. Comes in sublingual tablets (under the tongue) or oral tablets.

Side effects

Cause headaches in the majority of patients, really unpleasantly so. Theory is that this is due to vasodilation in the brain somewhere.

Only other real problem is that people can build up a tolerance to them, needing more and more for the same effect. To prevent this, it is recommended that patients have at least 4 hours a day without any nitrate.