Navigation for Departments

Prevention of further strokes

People who have had a transient ischaemic attack (TIA) or stroke are at risk of having further strokes and other conditions like heart attacks. The risks of further events are highest in the first few days, weeks and months of a stroke or TIA. The risk of a recurrent stroke after a TIA or ischaemic stroke is about 10% in the first year and then about five percent per year.

Secondary prevention is the management of people who have had prior strokes or transient ischaemic attack (TIA) to minimise the risk of further strokes and other vascular events such as heart attacks because the measures useful for stroke prevention are also very good at preventing heart attacks. All the preventive methods have additive effects and work together to reduce the risk.

Lifestyle modifcation

There are various lifestyle changes that will reduce the chances of a further stroke. They will also improve fitness and general health. They include smoking cessation, regular exercise and a healthy diet.

For further details, please see Life After A Stroke section.

 

Medication used after a stroke or TIA

Different combinations of tablets are used after a TIA or stroke depending on the clinical circumstances and the underlying cause of the stroke. The table given below should be used merely as a guide and more information sought from the doctor or pharmacist.

Antiplatlet drugs

These drugs act on platelets in the blood. Platelets are small cells that circulate in the blood and have a role in the prevention of bleeding. They stick to injured blood vessel walls and to one another to form a plug. By reducing the stickiness of platelets, these drugs reduce platelet aggregation and clot formation.

Aspirin (acetylsalicylic acid, ASA)


Why is it used? Aspirin is used in patients who have had a TIA ,stroke or heart attack to reduce the risk of having further atatcks. Different doses are used for this purpose, ranging from 50mg to 300mg/day, most commonly 75 milligrams.

How is it taken? It is taken once a day after a meal and not on an empty stomach. Since aspirin can irritate the stomach, it is best to take it with food or a full glass of water to help lessen possible stomach problems.

Possible side effects - stomach irritation and ulcers, bleeding from the stomach or elsewhere.

Clopidogrel (Plavix®)


Why is it used? Clopidogrel is used to help prevent another stroke or heart attack. It is usually used in people who are intolerant of aspirin. It is sometimes used in combination with aspirin in people with heart attacks. It is usually not used together with aspirin in strokes except in certain circumstances (your doctor will be able to give you more information about this).

How is it taken? You will take one 75mg tablet once a day in the morning (can be taken with or without food), or when and how your pharmacist and doctor tell you.

Possible side effects - abnormal or excessive bleeding.

Dipyridamole (Persantin Retard and others)


Why is it used? Dipyridamole is used to help prevent another stroke or TIA. It is usually not used alone but is combined with aspirin as the combination works better than either of the ingredients alone. A combination capsule containing both aspirin and Dipyridamole is available (Asasantin Retard).

How is it taken? Take one capsule containing 200 milligrams (the combination capsule contains 25 mg of aspirin as well) in the morning (with or without food) and one capsule in the evening (with or without food) to make up a total of two capsules a day. Do not chew it or crush it. It must be swallowed whole.

Possible side effects - Many patients starting the drug develop a severe headache due to the vessels in the brain vasodialating (expanding). This headache tends to decrease and go away as the body gets use to the medicine. Drugs like paracetamol can be taken to ease the headache. The other side effect is abnormal or excessive bleeding.

Anticoagulents

Anticoagulants are drugs that prevent the clotting of blood ('blood thinners'). The most commonly used one, Warfarin, acts by preventing the formation of some vitamin K dependent clotting factors. They are more effective than antiplatelet drugs in some situations.

Warfarin (Coumadin and others)


Why is it used? It is used to prevent strokes and TIAs that are caused by embolism from the heart. It prevents strokes in people who have a disturbance in the rhythm of the heart called atrial fibrillation (often referred to an irregular heart beat), people with artificial heart valves and sometimes in strokes caused by a heart attack. It may also be needed in some other circumstances and your doctor will be able to give you more information.

How is it taken? The dose of warfarin has to be carefully monitored by frequent blood tests and has to be adjusted from time to time. It is usually taken once a day in the evening (or at the same time every day). Most patients have to be followed up by an anticoagulant service either from the hospital or the GP. Patients need to be careful about their alcohol consumption and activities to prevent problems while taking the medication. The amount of alcohol consumed has to be reduced to a maximum of 3 units/day alcohol for men and 2 units/day for women. The levels of the drug in the body can be affected by the amount of vitamin K in your diet. However, most people need not take any special dietary precautions. Some drugs interfere with the way warfarin works and the dose of warfarin may need to be changed.

Possible side effects - Warfarin is a fairly strong blood thinner and there is a chance of bleeding more than usual with common cut, scrapes and falls. Use caution walking and with activities that place you at risk to fall or get hurt. Be careful while shaving, because a common cut may take longer to stop bleeding.


Antihypertensives

Antihypertensives are blood pressure lowering tablets and since high blood pressure is one of the major risk factors for stroke, they are very commonly used after a stroke. Research has shown that after a stroke lowering the blood pressure, even in people whose blood pressures are not too high to begin with, improves outcomes. High blood pressure is commonly thought to exist if blood pressure readings are consistently above 140/90. Very commonly, different tablets have to be combined to bring the blood pressure down. The following tables show only a few of the common tablets used to lower blood pressure.

Thiazide Diuretics (e.g. Bendroflumethiazide, Hydrochlorthiazide) and Indapamide (a thiazide like drug)


Why are they used? They work on the kidneys causing loss of salt and water. They are commonly called 'water tablets'.

How are they taken? They are usually taken once a day in the mornings.

Possible side effects - Deficiency of sodium and potassium in the body. Undue lowering of blood pressure. Raised blood sugars and gout.

Angiotensin Converting Enzyme (ACE) Inhibitors (e.g. Ramipril, Perindopril, Lisinopril, Enalapril and others)


Why are they used? They work on blood vessels and cause them to relax. They lower blood pressure and may have other beneficial effects.

How are they taken? They are usually taken once a day in the mornings or sometimes twice a day.

Possible side effects - Undue lowering of blood pressure. Dry cough. Impaired kidney function

Angiotensin Receptor Blockers (ARB) (e.g. losartan, candesartan, valsartan, eprosartan and others)


Why are they used? They work on blood vessels and cause them to relax. They lower blood pressure and may have other beneficial effects.

How are they taken? They are usually taken once a day in the mornings or sometimes twice a day.

Possible side effects - Undue lowering of blood pressure. Impaired kidney function

Calcium-channel blockers (e.g. verapamil, diltiazem, amlodipine, nifedipine, lercanidipine and others)

Why are they used? They work on blood vessels and cause them to relax. They also lower the force of the heart beat, causing lower blood pressure.

How are they taken? They are usually taken once a day in the mornings or sometimes twice a day.

Possible side effects - Constipation, headache, ankle swelling.

Beta-Blockers (e.g. atenolol, bisoprolol, metoprolol, carvedilol etc)


Why are they used? They reduce the rate and force of the heart beat. They lower blood pressure but are less commonly used as antihypertensives nowadays. They are more usually used for angina, after heart attacks, to treat heart failure and to treat heart rhythm disturbances.

How are they taken? They are usually taken once a day in the mornings or sometimes twice a day.

Possible side effects - Undue slowing of the heart beat. Colds hands and feet, worsening of asthma.

Cholesterol lowering tablets

It is common practice to lower blood cholesterol after heart attacks, peripheral arterial disease and ischaemic strokes (and TIAs). Cholesterol is a lipid (fat) found in cells and carried in the blood. High levels of cholesterol are associated with atheroma formation in blood vessels. Although a strict diet can reduce the blood cholesterol, research has shown that taking tablets (statins) to lower the cholesterol reduces the chances of further strokes and heart attacks. Two commonly used cholesterol drugs are described below.

Statins (e.g. simvastatin, pravastatin, atorvastatin and others)


Why are they used? Statins lower cholesterol by reducing the formation of cholesterol in the body. Statins help protect high-risk, people from heart disease and prevent further events in people who’ve already had a heart attack, stroke, TIA or peripheral artery disease. They are sometimes prescribed even for people without high levels of cholesterol as they seem to have benefits beyond just lowering the cholesterol levels

How are they taken? They are usually taken once a day in the evening or night.

Possible side effects - Muscle aches which can be treated by reducing the dose or changing to other statins. More serious muscle damage (rhabdomyoyisis) is very rare.

Ezetimibe

Why is it used? Ezetimibe reduces cholesterol by reducing the absorption of cholesterol in the intestines. It may be used alone when other cholesterol-lowering medications are not tolerated, or together with statins.

How is it taken? It is usually taken once a day.

Carotid Endarterectomy

A carotid endarterectomy is an operation to remove fatty deposits (plaque) from the carotid artery in the neck. This artery can become severely narrowed and this can lead to a stroke (cerebral infarct). Although tablets are effective, if the artery is very severely narrowed (more than 70%), research has shown that the best treatment is to have an endarterectomy. Patients have to be carefully chosen for this procedure and the risks and benefits taken into account before deciding to go ahead. The operation is used in people who have had a TIA or a minor stroke with good recovery.