Aspirin anti-platelet

About aspirin as an anti-platelet medicine

In the blood are sticky cells called platelets. When you cut yourself, the platelets stick to each other (clot) to seal the wound. Sometimes a clot may form in a blood vessel and block it, causing a stroke or heart attack.

Low doses of aspirin have an anti-platelet effect which means that it reduces the stickiness of platelets in the blood - this helps prevent unwanted blood clots from forming within the body. Anti-platelet doses of aspirin are particularly useful for patients who have angina (a type of chest pain) or who have had heart bypass surgery. It is also used for patients who have recently suffered from a heart attack or for those at risk of suffering from a heart attack or stroke.

At higher doses, aspirin is used to relieve pain and inflammation caused by rheumatic and muscular pain. For more information about this see the separate leaflet called 'Aspirin'.

Before taking aspirin as an anti-platelet medicine

Before taking aspirin make sure your doctor or pharmacist knows:

• If you are pregnant, trying for a baby or breast-feeding.
• If you are under 16 years of age.
• If you have a blood disorder such as haemophilia or G6PD deficiency.
• If you have ever had a peptic ulcer (stomach ulcer).
• If you suffer from asthma.
• If you have liver or kidney problems.
• If you have high blood pressure.
• If you have ever had an unusual or allergic-type reaction from taking aspirin or a non-steroidal anti-inflammatory drug (NSAID). NSAIDs include ibuprofen, diclofenac, indometacin and naproxen.
• If you are taking other medicines, including those available to buy without a prescription, herbal or complementary medicines.
• If you have ever had an allergic reaction to any other medicine.

How to take aspirin as an anti-platelet medicine

• Before beginning treatment, read the manufacturer's printed information leaflet.
• The usual dose is one (75 mg) tablet of aspirin each day or one capsule each day.
• Take your dose of aspirin with or after food to reduce the risk of stomach irritation.
• If you have been given the dispersible tablets, dissolve or mix your tablet in water before taking.
• If you have been given the enteric coated tablets, the aspirin is not released until the tablet has travelled through the stomach and reached the small intestine. This reduces the risk of stomach irritation. Such preparations should be swallowed whole and not crushed or chewed.
• If you have been given the modified release capsules, swallow your capsule whole, not crushed or chewed.
• Try to take aspirin at the same time each day to help avoid missing any doses.
• If you forget to take a dose, take it as soon as you remember and then continue as normal. Do not take two doses on the same day to compensate for a missed dose.

Getting the most from your treatment

• Avoid taking indigestion remedies at the same time of day as the enteric coated forms of aspirin. Indigestion remedies should be taken at least an hour before or an hour after a dose of aspirin.
• It is recommended that a preparation containing aspirin should not be given to children under the age of 16 unless it has been prescribed by a doctor to treat a specific condition. This is because there is a possible association between aspirin and Reye's syndrome when given to children. Reye's syndrome is a very rare disease that can be fatal.
• Before taking any 'over-the-counter' medicines, especially cold and flu preparations which may also contain aspirin, check with your pharmacist which medicines are safe for you to take.
• If you suspect that a child has taken aspirin or an adult has taken more than the prescribed dose, contact your local accident and emergency department for advice straight away.

Can aspirin taken as an anti-platelet medicine cause problems?

Along with their useful effects all medicines can cause unwanted side-effects. These usually improve as your body adjusts to the new medicine. Speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

How to store aspirin

• Keep all medicines out of the reach and sight of children.
• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

References

• Manufacturer's PIL, Angettes 75®, E. R. Squibb & Sons Limited, electronic Medicines Compendium. Dated June 2005, accessed September 2009.
• Manufacturer's PIL, Micropirin® 75 mg EC Tablets, Dexcel Pharma Ltd, electronic Medicines Compendium. Dated April 2009, accessed September 2009.
• British National Formulary; 58th Edition (September 2009) British Medical Association and Royal Pharmaceutical Society of Great Britain, London (link to current BNF).