The main aim in treating angina is to control the symptoms and:
- allow you to maintain as high a level of activity as possible
- improve your quality of life
- prevent worsening of the narrowed coronary arteries (important when deciding on your treatment plan)
If you have angina frequently it's likely that you'll need two or more drugs to relieve the pain, to prevent the pain from developing and to protect you from serious events such as heart attacks.
Different groups of drugs work differently and have different side effects. It is a case of finding the most effective ones for you with the fewest side effects. You may need to take a combination of drugs as this is often most effective.
It's important you take your drugs as prescribed. Speak to your doctor or phone the NHS 24 111 service for advice if a dose is missed or repeated.
If your angina is not being controlled with drug therapy, it is likely that your doctor will refer you to a cardiologist.
You can find information on some commonly used drugs for treating angina below.
Glyceryl Trinitrate (GTN)
GTN is used to relieve angina pain actively as it happens.
It's absorbed in the mouth, under the tongue (sublingual) making it effective in 1 to 2 minutes, lasting 20 to 30 minutes.
GTN can be used in tablet or spray form, whichever you prefer.
Explain to those around you about using your GTN. This will help alleviate any fears they have and give you reassurance that they will be able to help if needed.
Accepting the use of your GTN spray or tablets can take away fear of pain coming on.
GTN can also be used prior to doing an activity that you might be afraid will bring angina on. If you use your GTN and it wasn’t necessary, the worst thing likely to happen to you is a headache.
There's no limit to the number of occasions you can take GTN. It's not addictive and your body will not become used to it with frequent use.
How to use your GTN spray
If experiencing pain or breathlessness:
- sit down
- take a deep breath
- take 2 puffs of your GTN
- wait 5 minutes
If pain or breathlessness remains:
- take 2 puffs of your GTN
- wait 5 minutes
If still experiencing pain or breathlessness then call your GP or dial 999.
Side effects of GTN
Side effects of GTN include headaches and dizziness.
Antiplatelets reduce your risk of heart attack or stroke by interfering with the normal clotting mechanism in the blood, making it less likely to form clots.
Everyone with coronary artery disease should be prescribed an antiplatlet, usually aspirin.
Aspirin occasionally upsets the stomach causing indigestion. This may be avoided by taking your tablet with or after meals but speak to your doctor if you continue to suffer.
In the event of true aspirin intolerance or allergy, clopidogrel 75mg daily can be considered as an alternative for some people.
Dipyridamole is also an antiplatelet, more commonly associated with heart valve problems.
Beta-blockers are used to treat high blood pressure and angina.
Beta-blockers reduce the work your heart has to do by slowing down the heart rate and lowering the blood pressure. This makes them effective in reducing the number of angina attacks as well as allowing you to be more active.
Find out more about beta-blockers.
Statins – cholesterol lowering drugs
Your doctor may also ask you to take tablets to lower your cholesterol, called statins.
Even if your cholesterol is not especially high your doctor may prescribe tablets as a preventative measure.
Frequent stomach pains or muscle pains should be reported to your doctor when taking statins. You will also have to make changes to your diet to lower your cholesterol most effectively
Find out more about statins.
ACE inhibitors help to relax the arteries, lowering blood pressure and reducing the work the heart has to do.
They are used to treat high blood pressure as well as other heart problems, particularly when there has been some damage to the heart muscle such as from a heart attack.
They are also known to act preventatively in reducing the risk of heart attacks and stroke in people who have coronary heart disease.
Find out more about ACE inhibitors on the Blood Pressure UK website
Angiotensin receptor blockers (ARBs)
Angiotensin receptor blockers (ARBs) are mainly used for angina when ACE inhibitors are not suitable.
They act in much the same way as ACE inhibitors and may be used in combination with them where there's been some previous damage to the heart muscle, such as from a heart attack.
Find out more about ARBs on the Blood Pressure UK website
Nitrates are used to treat angina and heart failure as they reduce the amount of work the heart muscle has to do. They open up the arteries by relaxing the muscle in the artery wall, causing the blood vessels to dilate.
Some are ‘slow release’ or ‘modified release’ tablets. When you swallow these they gradually release a steady amount of nitrate, which is absorbed into the body.
They should be taken at the times prescribed in order for them to work effectively:
- Isosorbide Mononitrate - usually taken once a day
- Isosorbide Dinitrate - usually taken at 12 hourly intervals (twice a day).
If nitrate stays in your bloodstream all the time, your body becomes used to it and the nitrate then has much less of an effect. To overcome this ‘tolerance’ you will be prescribed medication so that your blood stream will be free of nitrate for a few hours each day.
Isosorbide dinitrate can also be used to relieve pain during an attack in different forms.
Some come as skin patches or ointments, which release a steady amount of nitrate into the bloodstream through the skin.
Patches should be applied to the chest or back and not directly over the heart.
Only one patch should be used a day, which should be removed at night unless specifically being used to combat nighttime angina.
Apply the patch to a different area of skin every time and don't apply the patch to inflamed or cracked skin (the medicine can be absorbed too rapidly).
Calcium channel blockers
Calcium channel blockers help to relax the arteries, lowering blood pressure and reducing the work the heart has to do. This makes them effective in reducing the number of angina attacks as well as allowing you to be more active.
Sometimes calcium channel blockers, such as Diltiazem, are used in combination with beta-blockers to control angina.
Sometimes they are used for people who are not able to take beta-blockers. For example, Verapamil is used in place of a beta-blocker when someone has severe COPD (chronic obstructive airways disease) or asthma.
Calcium channel blockers tend to be less effective if you smoke.
Potassium channel activators
Potassium channel activators work partly like a nitrate and partly like a calcium channel blocker.
They tend to be used in combination with other drugs and can be helpful when angina is not well controlled by other drugs.
If you have unstable angina (where symptoms develop rapidly and persist even when you are at rest), when admitted to hospital you'll be given medication to prevent blood clots developing and reduce your risk of having a heart attack.
This will usually be aspirin, used for its blood thinning abilities rather than as a painkiller, unless there is a reason you are unable to take aspirin such as having a history of liver disease.
You may also be prescribed another blood-thinning medication called clopidogrel, which you may need to take for a number of months.
Some people are only prescribed one of these medications.
You may also be given an injection of an additional blood thinning medication.
If the risk is moderately high, a coronary angiogram may be carried out to assess the size and location of the blockage in your coronary artery. If the blockage is significant, a CABG or a PCI can be performed.