Hesperian Health Guides

Medicines for Heart Attack

Heart Disease and High Blood Pressure: Medicines

If you suspect someone is having a heart attack, give 1 tablet of aspirin right away (300 to 325 mg). Ask the person to chew it up and swallow it with water. Even if you are not sure the person is having a heart attack, aspirin will do no harm. On the way to a hospital, give nitroglycerin if you have it.

You can also give morphine to help with the pain and fear, and make it easier for the heart to pump. There is more information about morphine in the chapter on First Aid.

Nitroglycerin (Glyceryl trinitrate)

Nitroglycerin is used to treat chest pain from a heart attack. It helps to widen the blood vessels making it easier for the heart to pump blood.

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Do not give nitroglycerin to someone with low blood pressure or who has taken sildenafil (Viagra) in the last 24 hours. This combination of medicines can cause blood pressure to drop dangerously low, and can be deadly.

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May cause severe headache, feeling hot, or dizziness.

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The person should sit or lie down, not stand up, in case they get dizzy.

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Give ½ mg (0.5 mg) dissolved under the tongue, no more than 3 times, waiting 5 minutes between each tablet. If the chest pain and other signs go away, another tablet is not needed.


Do not chew or swallow nitroglycerin tablets. As the tablet dissolves under the tongue, it tingles or even burns a little.


This page was updated:05 Jan 2024