nitroglycerin (nitr) /-glis′ərin/ , a potent smooth muscle relaxant and vasodilator used in transdermal patches and in a paste as well as in oral and sublingual tablets. Also called glyceryl trinitrate. ▪ INDICATIONS: It is prescribed for the prevention or relief of angina pectoris. There are recommended limits to the amount of nitroglycerin use before calling for emergency assistance (no more than 3 sublingual tablets at 5-minute intervals). The drug should not be used continuously, because tolerance develops within 24 to 48 hrs. Nitroglycerin is also used to treat pulmonary hypertension, to help treat congestive heart failure following acute myocardial infarction, and to treat hypertensive emergencies during cardiovascular surgery. ▪ CONTRAINDICATIONS: Head trauma, severe anemia, narrow-angle glaucoma, and known hypersensitivity to this drug or other organic nitrates prohibit its use. It should not be used by patients taking sildenafil or similar agents for treating erectile dysfunction. ▪ ADVERSE EFFECTS: Among the most serious adverse effects are hypotension, flushing, headache, and syncope.
