What is nitroglycerin?
Nitroglycerin is a vasodilator, a medicine that opens blood vessels to improve blood flow. It is used to treat angina symptoms, such as chest pain or pressure, 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 quick-acting forms and long-acting forms.
Quick-acting forms of nitroglycerin are used to relieve angina or used just before activities that typically cause angina. The quick-acting forms include tablets or oral sprays. The tablets are placed under the tongue (sublingual) or between the cheek and gum (buccal). The spray is used on or under the tongue. This topic covers these quick-acting forms of nitroglycerin.
Long-acting forms of nitroglycerin are used to prevent angina from happening. They are not used to stop sudden symptoms of angina. These long-acting forms include pills, tablets, skin ointment, and skin patches. This topic does not cover these long-acting forms of nitroglycerin.
Your doctor will prescribe the right amount for you. Do not use another person's nitroglycerin.
When do I use quick-acting nitroglycerin?
Your doctor will advise you when to use your nitroglycerin. In general, quick-acting nitroglycerin is used:
- To relieve sudden angina.
- Before stressful activities that can cause angina, such as walking uphill or having sexual intercourse.
How do I use quick-acting nitroglycerin?
- Sit or lie down to take your nitroglycerin. If you are driving, pull over and park the car. Taking nitroglycerin can lower your blood pressure, which could cause you to pass out if you are standing up.
- For sudden episodes of angina, use nitroglycerin in a tablet or liquid spray form.
- Place the under-the-tongue (sublingual) tablet under your tongue. Leave it there until it dissolves. If you accidentally swallow the tablet, take another. The medicine won't work if it is swallowed.
- Place the between-cheek-and-gum (buccal) tablet between your cheek and gum. Leave it there until it dissolves. If you accidentally swallow the tablet, take another. The medicine won't work if it is swallowed.
- Use the spray under your tongue or on top of your tongue. Push the spray canister button once. Close your mouth right away.
- Take one tablet or spray dose. If after 5 minutes your angina symptoms are not better or get worse, call 911 or other emergency services immediately.
- After you call 911, continue to stay on the phone with the emergency operator. He or she will give you further instructions.
- Regardless of what happens, you should let your doctor know that you had an episode of angina. If this is unusual for you, if your angina episodes are occurring more frequently or lasting longer, or if you need more medicine to control them, tell your doctor.
Are there side effects or interactions with other drugs that I should be aware of?
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 an erection-enhancing medicine if you are taking nitroglycerin. These medicines include sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra). Combining nitroglycerin with any of these medicines can cause a life-threatening drop in blood pressure. If you have angina and have taken one of these erection-enhancing medicines, be sure to tell your doctor 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.
How should I store nitroglycerin?
Store nitroglycerin pills in a dark-colored (such as brown), airtight, glass container that you cannot see through. Keep the container tightly closed. Keep nitroglycerin pills and liquid spray away from heat or moisture.
Can nitroglycerin get old and lose potency?
Nitroglycerin can get old. And when it is old, it may not work. If your nitroglycerin supply is past its expiration date, get a new prescription as soon as possible. Keep your nitroglycerin in the container it came in and tightly closed. Do not open your sublingual nitroglycerin until you need a dose. Replace your tablets every 3 to 6 months. A nitroglycerin spray may last up to 2 years before it expires.
You may get a headache when you use nitroglycerin. Or you may feel burning or tingling under your tongue with nitroglycerin that is used under the tongue. But if you don't have a headache or feel burning or tingling under your tongue, it does not mean the medicine is not working.
Other Works Consulted
- O'Connor RE, et al. (2010). Acute coronary syndromes: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 122(18): S787–S817.
- O'Gara PT, et al. (2013). 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: Executive summary. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 127(4): e362–e425.
Current as of: December 15, 2019
Author: Healthwise Staff
Rakesh K. Pai MD, FACC - Cardiology, Electrophysiology
E. Gregory Thompson MD - Internal Medicine
Martin J. Gabica MD - Family Medicine
Adam Husney MD - Family Medicine
Stephen Fort MD, MRCP, FRCPC - Interventional Cardiology
Current as of: December 15, 2019