Medication after a Heart Attack (Myocardial Infarction)

 

If you have had a myocardial infarction (a heart attack), it is common to be advised to take four medicines for the rest of your life. These are: aspirin (or similar), a beta-blocker, an ACE inhibitor and a statin. These medicines are likely to improve your outlook. Also, an additional antiplatelet medicine (e.g. Plavix) may be advised for a period of time. However, this is a general article and it is not a substitute for advice from your doctor.  You may be advised differently if you have other diseases, develop complications, or have allergies or side-effects to certain medicines. Your doctor will advise what is best for your particular circumstances.

Why are these medicines prescribed after myocardial infarction?

  • To reduce the chance of another myocardial infarction (MI).
  • To help to prevent heart disease from getting worse.

The medicines are usually taken each day for life. This leaflet discusses the typical situation. However, the exact medicines prescribed for you can depend on factors such as the type of heart attack you had, as well as any other illnesses you may also have. Your doctor will discuss your medicines in more detail.

 Aspirin (ASA) – helps to prevent blood clots

Aspirin works by reducing the stickiness of platelets. Platelets are tiny particles in the blood that help the blood to clot if a blood vessel is cut. However, if a blood clot forms inside a blood vessel taking blood to the heart muscle, it blocks the flow of blood. This can cause an MI. Therefore, aspirin reduces the chance of blood clots forming which reduces the chance of a further MI.

If you cannot take aspirin (for example, if you are allergic to it) then another antiplatelet medicine (such as clopidogrel or ticagrelor) may be used instead.

Aspirin is usually taken for the rest of your life. Also, you will normally be advised to take another antiplatelet medicine (clopidogrel or ticagrelor) in addition to aspirin. However, this is usually only advised for a number of weeks or months, depending on the type and severity of your MI.

Beta-blockers – help to protect the heart

Beta-blockers work by easing the workload of the heart by blocking the beta receptors on heart muscle cells. A receptor is a tiny part on the wall of certain cells. There are different types of receptors throughout the body. The beta receptors on heart muscle cells are stimulated by the hormones adrenaline (epinephrine) and noradrenaline (norepinephrine). When the beta receptors are stimulated, they make the heart muscle cells work harder which increases the heart rate and blood pressure.

Beta-blocker medicines block beta receptors from being stimulated. This prevents the heart rate from going too fast, reduces blood pressure and helps to stabilize the electrical activity of the heart. Beta-blockers are also used to treat angina and high blood pressure. There are a few different beta-blockers for your doctor to choose from.

  • Most people do not develop any side-effects. However, tell your doctor if you have any side-effects. The most common are: cool hands and feet, sleeping problems, difficulty getting and maintaining an erection, pins and needles, and tiredness. A change in dose or preparation may help if you develop any troublesome  side-effects.

ACE inhibitors – help to protect the heart

One of the actions of an angiotensin converting  enzyme (ACE) inhibitor is to interfere with a chemical (enzyme) found in the bloodstream, called angiotensin. Blocking this enzyme widens blood vessels and lowers the blood pressure. This eases the burden on the heart. ACE inhibitors also appear to have a direct action on the heart, which has a protective effect. There are a few ACE inhibitors for your doctor to choose from.
Angiotensin-II receptor antagonists (also called angiotensin receptor blockers) have a similar effect as ACE inhibitors and are sometimes used as an alternative. If you have side-effects with an ACE inhibitor your doctor may suggest trying them instead.

 Statins- to lower the cholesterol level

Statins work by reducing the amount of cholesterol that is made in the liver. Cholesterol contributes to the build-up of atheroma. Patches of atheroma are like fatty lumps that build up on the inside lining of blood vessels. A build-up of atheroma can lead to heart disease, strokes and other blood vessel problems. In general, the lower the cholesterol level, the better. Most people who have an MI are advised to take a statin.

Most people who take a statin have no side-effects, or only minor ones. Read the information leaflet that comes with your particular brand for a full list of possible side-effects. These include: headache, pins and needles, abdominal pain, bloating, diarrhea, feeling sick, and a rash.

Some points to remember about statins:

  • Tell your doctor if you have any unexpected muscle pains, tenderness, cramps or weakness. This is because a rare side-effect of statins is a severe form of muscle inflammation.
  • You should not take a statin if you have active liver disease, if you are are pregnant or intend to be pregnant, or if you are breast-feeding. You should stop taking a statin if you develop liver disease.
  • Do not eat grapefruit or drink grapefruit juice if you are taking a statin. A chemical in grapefruit can increase the level of statin in the bloodstream which can make side-effects from the statin more likely.
  • Various other medicines that you may take can interfere with statins – for example, some antibiotics and cyclosporine.  The doses of either the statin or the other medicine may need to be adjusted. Therefore, if you are prescribed (or buy) another medicine, remind the doctor or pharmacist that you are on a statin in case it is one where an interaction may be possible.
  • Tell a doctor if you develop chest symptoms such as unexplained shortness of breath or cough. This is because, in very rare cases, statins may cause a disease called interstitial lung disease.

Self-help measures

In addition to taking medication, there are various things you can do to help to reduce your risk of having another MI.

Medications are used in addition to any relevant lifestyle changes which also help to prevent heart disease from becoming worse. These include:

  • Stopping smoking if you are a smoker.
  • Taking regular exercise  (unless advised otherwise by your doctor).
  • Losing weight (if you are overweight).
  • Eating a healthy deit, including oily fish at least 2-3 times a week.

 

Source: British Heart Association

About Dr. Hassan Gargoum

Clinical Professor of Medicine, University of Saskatchewan Consultant, Cardiovascular Diseases

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