This drug is used to control high blood pressure, congestive heart failure, lung congestion and chest pain especially in heart attack patients. It decreases the workload on the heart by enlarging (dilating) blood vessels.

Nitroglycerin relaxes blood vessels allowing more blood to flow through and improves blood flow to the heart. Topical nitroglycerin skin patches are used to prevent angina (chest pain). This medication is NOT for treating an attack of chest pain that has already started.