Take nitroglycerin tablets under your tongue at the first sign of chest pain

Nitroglycerin tablets work fastest when placed under your tongue rather than swallowed. The tablet dissolves in the blood vessels under your tongue and enters your bloodstream within one to three minutes. Sit down when ready when you feel chest pain, place one tablet under your tongue, and let it dissolve completely without chewing or swallowing it. Most people feel relief within five to ten minutes.

If the pain does not improve after five minutes, take a second tablet the same way. Wait five more minutes. If pain persists after a third tablet (taken five minutes after the second), call 911 or your local emergency number — do not drive yourself to the hospital. Keep a record of how many tablets you needed and when you took them, because this information helps your doctor understand your condition.

Key Takeaways

  • Place the tablet under your tongue and let it dissolve; do not chew, swallow, or place it in your cheek.
  • Sit down before taking the tablet and stay seated for at least five to ten minutes while it works.
  • If chest pain does not improve after one tablet, take a second tablet five minutes later, then a third five minutes after that.
  • Call 911 when ready if three tablets over fifteen minutes do not relieve the pain, or if the pain feels different from your usual chest pain.
  • Store nitroglycerin tablets in a cool, dark place in their original amber bottle, and replace them every six months or as directed by your pharmacist.

Prepare your body and environment before taking the tablet

Sit down in a comfortable chair or lie down as soon as you feel chest pain starting. Do not stand or continue physical activity. Nitroglycerin can cause a sudden drop in blood pressure, which may make you feel dizzy or faint — sitting prevents you from falling if this happens. Loosen any tight clothing around your neck or chest.

If you are outdoors or in an unsafe location, move to a safe spot first. If you are driving, pull over safely before taking the tablet. Never take nitroglycerin while driving or operating machinery, because dizziness or lightheadedness can develop within minutes.

Place the tablet correctly under your tongue

Open the amber bottle and remove one tablet with dry fingers. Do not touch the tablet more than necessary, because moisture and heat from your skin can damage it. Place the tablet directly under your tongue, in the pocket of tissue between your tongue and the floor of your mouth.

Close your mouth and keep the tablet in place while it dissolves. Do not chew it, swallow it whole, or move it around your mouth. Do not eat, drink, or smoke while the tablet is dissolving. The entire tablet should dissolve within one to three minutes, leaving little or no residue. If a white powder remains after five minutes, spit it out gently.

Recognize when the tablet is working and when to take another

Nitroglycerin often causes a slight tingling or burning sensation under your tongue — this is normal and means the tablet is dissolving properly. You may also feel a mild headache, flushed skin, or a slight increase in heart rate. These side effects usually fade within thirty minutes and are signs the medication is active in your body.

Chest pain should begin to ease within five minutes. If it does not improve at all after five minutes, or if the pain is spreading or worsening, take a second tablet under your tongue. Wait another five minutes. If pain persists after the third tablet, call 911 when ready — this may indicate a heart attack rather than angina, and you need emergency care.

Store nitroglycerin tablets so they stay effective

Keep your nitroglycerin in its original amber or dark glass bottle with the cap tightly closed. The amber color protects the tablets from light, which breaks down the active ingredient. Store the bottle in a cool, dry place — not in the bathroom (humidity damages them) or in direct sunlight. A bedroom nightstand or kitchen cabinet away from heat works well.

Check the expiration date on your bottle every month. Nitroglycerin loses strength over time, especially if exposed to air, moisture, or heat. Most tablets should be replaced every six months, though some formulations last longer — your pharmacist will tell you the replacement schedule for your specific prescription. If your tablets no longer cause the slight tingling sensation under your tongue, they have likely expired and should be replaced.

Know what to do if side effects are severe or unusual

Mild headache, flushed skin, and slight dizziness are common and usually fade within thirty minutes. However, if you experience severe headache, fainting, or a sudden drop in blood pressure (feeling very weak or unable to stand), lie down with your legs elevated and call your doctor or poison control. Do not take another dose if you feel faint.

If you have taken nitroglycerin and develop new symptoms — such as shortness of breath that does not improve, nausea, or pain in your jaw or arm — call 911. These may indicate a heart attack. Never assume nitroglycerin has solved the problem if your symptoms change or worsen.

Carry nitroglycerin with you and tell others where it is

Keep your nitroglycerin bottle in a pocket, purse, or bag you carry every day. Do not leave it at home. If you live with family or work with colleagues, tell them where you keep your tablets and what to do if you collapse — they may need to retrieve the bottle and call 911 on your behalf.

If you travel, keep nitroglycerin in your carry-on bag, not in checked luggage. Airport security allows nitroglycerin tablets in carry-on bags. If you travel across time zones or will be away from home for an extended period, bring extra tablets and refill your prescription before you leave so you do not run out.

Frequently Asked Questions

Can I chew or swallow nitroglycerin tablets?

No. Chewing or swallowing nitroglycerin tablets delays how fast they work — they are designed to dissolve under your tongue so the medication enters your bloodstream quickly. Swallowing sends the tablet to your stomach, where it works much more slowly and less effectively for sudden chest pain.

What should I do if I accidentally swallow a tablet?

Do not panic. Swallowing one tablet is not dangerous, though it will work more slowly. Take another tablet under your tongue as directed. If you swallow multiple tablets or feel severe dizziness or fainting, call poison control or 911.

How long does nitroglycerin stay in my system?

Nitroglycerin tablets work for five to thirty minutes, depending on the dose and your body. The effects usually fade within thirty minutes. If you need pain relief beyond that, your doctor may prescribe a longer-acting form of nitroglycerin, such as a patch or extended-release tablet taken daily.

Can I take nitroglycerin if I have taken erectile dysfunction medication?

No. Combining nitroglycerin with medications like sildenafil (Viagra) or tadalafil (Cialis) can cause a dangerous drop in blood pressure. Tell your doctor about all medications you take, including over-the-counter and herbal products, before using nitroglycerin.

What if my chest pain does not go away after three nitroglycerin tablets?

Call 911 when ready. Chest pain that does not respond to nitroglycerin may indicate a heart attack or another serious condition that requires emergency care. Do not wait or try additional doses — emergency responders need to evaluate you right away.