What is angina?

This is chest pain or discomfort caused by a condition called "coronary artery disease" (also called "coronary heart disease"). In this condition, the arteries that supply the heart with blood get clogged with fatty deposits. When the vessels get too narrow, the heart muscle does not get enough blood. This causes chest pain or discomfort, especially during physical activity.

What do medicines for angina do?

They help prevent or ease chest pain or discomfort (figure 1). They can:

• Relax blood vessels going to the heart muscle – This lets more blood flow to the heart.

• Reduce the amount of work the heart muscle has to do

What medicine should I take?

Your doctor will decide which medicine is best for you. Some people take just 1 medicine for angina. But the first medicine you try might not help enough. If that happens, tell your doctor or nurse. People sometimes need to try a few different medicines before they find the treatment that works for them. And some people take 2 or 3 medicines together.

There are 4 types of medicines used to treat angina (table 1). They are listed below.

Nitrates

These come in many different forms, including:

• Pills or powder that go under your tongue

• Sprays that go on or under your tongue

• Pills you swallow

• Patches you wear on your skin

• Ointment you put on your skin

Your doctor will decide which form of nitrate is best for you. It depends on how often you get angina, how long it usually lasts, and what kinds of situations cause you to get it. Your doctor might tell you to take under-the-tongue nitrates before you exercise. This can prevent angina. Keep nitroglycerin tablets in the bottle they came in, with the cap on tightly.

If you take nitrates, there are some things you should know:

• Call for an ambulance if your chest pain lasts – Your doctor might tell you to take 2 to 3 doses of under-the-tongue or spray nitroglycerin spaced 5 minutes apart when you get angina. But if your angina lasts more than 5 minutes after you take your last dose, call for an ambulance right away (in the US and Canada, call 9-1-1). You might be having a heart attack.

• Be aware of the side effects – The side effects include a fast heart rate, headache, feeling lightheaded, fainting, and "flushing." Flushing is when your skin gets red and feels hot, especially on your face. Sit down when you take under-the-tongue or spray nitroglycerin to lower your risk of fainting. Older people are more likely to get lightheaded than younger people, especially in hot weather. Drinking alcohol can make nitrate side effects worse, so be very careful when taking these medicines.

• Avoid erection medicines – If you take nitrates, do not take medicines to help you get or keep an erection. These include sildenafil (brand name: Viagra), vardenafil (brand name: Levitra), and tadalafil (brand name: Cialis). Taking these medicines with nitrates is very dangerous.

Beta blockers

These are usually taken 1 or 2 times a day to prevent angina. There are many different types of beta blockers. Your doctor will choose the best one for you based on your age and any other health problems you might have.

When you first start taking beta blockers, they might make you feel tired. This only happens while your body gets used to the medicine. You might have other side effects, such as breathing problems or trouble getting an erection. You might need to try many different beta blockers to find the one that causes the fewest side effects and works best for you.

Calcium channel blockers

Doctors usually only give these to people who:

• Can't take beta blockers because of side effects or because of other health problems

• Still have angina even though they take nitrates and beta blockers

Side effects from calcium channel blockers include:

• Flushing

• Dizziness and lightheadedness

• Headache

• Swelling of the feet and ankles

• Constipation

The side effects depend on the kind of calcium channel blocker. You might need to try many different kinds to find the one that causes the fewest side effects and works best for you.

Ranolazine

Doctors give this to people who still have angina even while taking a combination of beta blockers, calcium channel blockers, or nitrates. The side effects include:

• Feeling dizzy

• Headache

• Nausea

• Constipation

For more detailed information about your medicines, ask your doctor or nurse for the patient drug information handout from UpToDate. It explains how to use each medicine, describes its possible side effects, and lists other medicines or foods that can affect how it works.

Images

figure 1: How medicines prevent or treat angina

Some angina medicines work by expanding the walls of the coronary arteries, so that more blood can get through. Others work by reducing the amount of work the heart has to do. That way, the heart muscle needs less blood.

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