Nitroglycerin is a vasodilator, a medicine that opens blood vessels to improve blood flow. It is used to treat angina-a type of chest pain-that happens when there is not enough blood flowing to the heart. To improve blood flow to the heart, nitroglycerin opens up (dilates) the arteries in the heart (coronary arteries), which improves symptoms and reduces how hard the heart has to work.
Nitroglycerin comes in a quick-acting tablet or spray form or as a long-acting pill. The quick-acting pill or spray forms are used under the tongue (sublingually). Your health professional will prescribe the right amount for you. Do not use another person's nitroglycerin.
Your health professional will advise you when to use your nitroglycerin. Generally, nitroglycerin under the tongue is used:
A fresh tablet should taste bitter and sting when you put it under your tongue. If it does not, it probably is not effective and you should take another.
Normal, temporary side effects of nitroglycerin include a warm or flushed feeling, headache, dizziness, or lightheadedness. You may also feel a burning sensation under your tongue.
Do not take the erection-enhancing medicines sildenafil (Viagra), vardenafil (Levitra), or tadalafil (Cialis) if you are taking nitroglycerin. Combining nitroglycerin with any of these medicines can cause a life-threatening drop in blood pressure. If you develop chest pain and have taken one of these erection-enhancing medicines, be sure to tell your health professional so that you are not given nitroglycerin or another nitrate medicine.
Do not take the pulmonary hypertension medicine sildenafil (Revatio) if you are taking nitroglycerin or another nitrate medicine.
Store nitroglycerin pills in a dark-colored (such as brown), airtight, glass container that you cannot see through. Keep nitroglycerin pills and liquid spray away from heat and moisture.
If nitroglycerin is old, the tablets may not work well. Get a new prescription as soon as possible if your supply is past the expiration date. Usually you should replace your tablets every 3 to 6 months. A nitroglycerin spray may last up to 2 years before it expires.
There are ways to tell whether your nitroglycerin is still effective. You should have a headache when you use it. Or if you use nitroglycerin under your tongue, you should feel a slight tingle or burn when you place it there. If you do not notice these signs, your nitroglycerin is probably old. In this case, contact your health professional to get a new prescription. Fill the prescription as soon as possible, and discard your out-of-date nitroglycerin.
WebMD Medical Reference from Healthwise