Depending on the dosage and how it is taken, nitrates may help prevent attacks of angina, or relieve an attack that is occurring. Nitrates do this by increasing blood flow to the heart, and reducing the heart's workload.
Nitrates are available in several forms, as well as traditional tablets and capsules.
Nitroglycerin is available as a patch that releases medicine through the skin, sublingual tablets that dissolve underneath your tongue, and ointment that is absorbed through your skin. All of the dosage forms may cause similar side effects. These include headache, dizziness, flushing and sweating. The patch may also cause some itching or a rash on the skin. Sublingual nitrates may cause a local burning or stinging.