Fast-Acting Nitroglycerin

Fast-Acting Nitroglycerin

Nitroglycerin relieves angina (chest pain) by getting more blood and oxygen to your heart. Fast-acting nitroglycerin can stop an angina attack. Follow the steps below for taking fast-acting nitroglycerin. Note: Your healthcare provider may give you slightly different instructions. If so, follow them carefully.

To Stop an Angina Attack

Sit down before you take your nitroglycerin. The medication may make you feel dizzy.

Image of taking pill


Image of using spray

If you use tablets:

  • Place one tablet under your tongue. Or place it between your lip and gum or between your cheek and gum.

  • Let the tablet dissolve all the way. Do not swallow or chew the tablet.

  • Do not eat, drink, smoke, or chew tobacco as the tablet is dissolving.

If you use spray:

  • Open your mouth and hold the sprayer just in front of your mouth.

  • Press the button on the top. Spray once on or under your tongue. Do not inhale.

  • Close your mouth. Then wait a few seconds before you swallow.

After taking one tablet or spraying once:

  • Continue sitting for 5 minutes. 

  • If the angina goes away completely, rest for a while and continue your normal routine.

Call 911 if your angina lasts longer than 5 minutes and 1 tablet or 1 spray has not relieved it. Do not delay—you may be having a heart attack, also known as acute myocardial infarction, or AMI!

After you call 911, take a second tablet. Or, spray a second time. Wait another 5 minutes. If the angina still does not go away, take a third tablet, or spray a third time. Do not take more than 3 tablets, or spray more than 3 times, within 15 minutes. Stay on the phone with 911 for further instructions.


  • Limit the amount of alcohol you drink. Too much alcohol can cause dizziness or fainting.

  • Tell your healthcare provider about any medications, supplements, or herbs you use. Nitroglycerin can interact with other medications and cause serious problems. NOTE: Do not take Viagra, Levitra, or Cialis at any time if you are on nitroglycerin treatment. The combination of nitroglycerin with Viagra, Levitra, or Cialis can cause a severe drop in blood pressure. This can lead to dizziness, fainting, heart attack, or stroke.

  • Check the expiration date. Nitroglycerin can lose its effectiveness over time.

  • Tell your doctor if your angina attacks last longer, occur more often, or are more severe.