Do I Need Nitroglycerin for Sudden Chest Pain?

Medically Reviewed by James Beckerman, MD, FACC on August 17, 2022

Do you know whether to take your nitroglycerin tablets before, during, or after chest pain? And are there times when you shouldn’t take it at all?

Doctors usually prescribe nitroglycerin for angina pectoris, which often is called just "angina." It’s sudden heart-related chest pain. It happens because something prevents the flow of blood to your heart muscle.

Nitroglycerin helps widen the blood vessels so more blood gets to your heart muscle. That helps stop the pain.

Your doctor may give you instructions to take your nitroglycerin before you have angina. That means taking it before activities that are more likely to cause it.

For example, you might take it 5 to 10 minutes before you go for a bike ride. You might also take it before:

You may take your nitroglycerin when you first feel the symptoms of angina. It’s important to know your own body and what angina is like for you. You may have:

  • Aching, discomfort, or pain in your chest
  • Aching, discomfort, or pain in your jaw, throat, shoulders, arms, or upper belly or abdomen
  • Trouble breathing or shortness of breath
  • Tiredness (fatigue)
  • Nausea, a feeling of fullness or bloating, or gas

If you have angina, take your nitroglycerin as instructed by your doctor. This might mean you take it as soon as you feel symptoms, or you wait a minute before you take it, or you take more than one pill over several minutes.

If you take your nitroglycerin as instructed and you still have chest pain, get medical help right away.

As with any medicine, nitroglycerin might be harmful if you don’t take it correctly.

You should not take nitroglycerin if:

  • You have taken the maximum amount of short-acting nitroglycerin prescribed by your doctor
  • You know your blood pressure is very low. Ask your doctor about this.
  • You take medicine for erectile dysfunction

Men with heart disease and other long-term health problems are more likely to have erectile dysfunction (ED) or trouble with erections. There are medicines that help men who have ED. You or your partner may take one of them.

Prescription ED pills include:

Why shouldn’t you take your ED medicine with your nitroglycerin? The reason is that both lower your blood pressure. Taken together, your blood pressure may get to a very low, and dangerous, level.

Because of this effect, the American Heart Association warns against it.

You may still be able to take both medicines, at different times. Talk with your doctor about how long you should wait between taking the two medicines. For example, you may have to allow 24 to 48 hours or more between taking your ED medicine and nitroglycerin

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Warnica, J. Angina Pectoris, Cardiovascular Disorders, Merck Manual Professional Version, Merck & Co., Inc. 2016.

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