To prevent angina

If you use a patch:

• Remove the old patch. Then apply a new one to a clean, dry place on the chest or upper arm.

• Pick a new place each time you change the patch.

• Don't put the patch where skin is hairy, cut, irritated, scarred, or tattooed.

If you use a tablet or capsule:

• Take the tablet or capsule 1 hour before or 2 hours after eating.

• Swallow it with a glass of water. Don't break, chew, or crush the tablet or capsule.

If you use an ointment:

• Measure the prescribed amount of ointment onto the paper that comes with it.

• Spread a thin, even layer on a clean patch of skin. Don't rub it in. Tape the paper in place with skin tape for as long as instructed, then remove it. 

• Use a new spot each time you apply the paste.

 Precautions

• Don't suddenly stop using nitroglycerin to prevent angina. This could cause an angina attack. Check with your healthcare provider first.

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

• Tell your healthcare provider about any medicines, supplements, or herbs you use. Nitroglycerin can interact with other medicines and cause serious problems. 

• Don't take phosphodiesterase inhibitors such as sildenafil (Viagra). These are medicines that help sexual function in men but are very dangerous if taken any time if you are on nitroglycerin.

• Check the expiration date. Nitroglycerin can lose its effectiveness over time. Nitroglycerin must be protected from both heat and light.

Call your healthcare provider right away if you have:

• Chest pain that lasts longer, is different or more severe, or occurs more often

• Irregular heartbeat

• Shortness of breath

• Blurred vision

• Dizziness or you pass out

• Severe headache