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Brand Name(s) : Micropirin, Nu-Seals, Caprin, Resprin, Anadin original (combination with caffeine), Anadin Extra (combination with caffeine and paracetamol), Alka-Seltzer Original (combination with sodium hydrogen carbonate, citric acid), Alka-Seltzer XS (combination with paracetamol, citric acid, caffeine and sodium hydrogen carbonate), Asasantin Retard (combination with dipyridamole), Beechams Powders (combination with caffeine), Migramax (combination with lysine acetylsalicylate and metoclopramide hydrochloride), Co-codaprin (combination with codeine phosphate)
Side Effects


Aspirin should be used with caution in: the elderly, patients with an allergic disease, asthma, liver or kidney problems, uncontrolled high blood pressure (hypertension), patients who have previously had stomach (peptic) ulcers and in those who are deficient in the enzyme called glucose-6-phosphate dehydrogenase (common in peoples from Africa, Asia, Oceania and Southern Europe).

It should not be used in: people who are allergic (hypersensitive) to aspirin or other drugs of this class (NSAIDs), those who currently have stomach ulcers (peptic ulcers), women who are breastfeeding, children under 16 years of age unless specifically prescribed by a doctor for a disease requiring aspirin treatment (e.g. Kawasaki's disease), people with a blood-clotting disorder (e.g. haemophilia), gout, or severe liver or kidney problems.

Also see list of precautions and interactions.


Store below 25°C


Aspirin is used to treat or prevent a number of problems.

It is a member of the class of drugs called non-steroidal anti-inflammatory agents (known as NSAIDs) and is sometimes called acetylsalicylic acid.

In general, this drug is used as required to relieve minor aches and pains and to reduce fever and inflammation, but at low doses and taken regularly it can be prescribed as an antiplatelet to help prevent blood cells sticking together and forming a blood clot. It can be useful to help prevent blood clots in people who have had a stroke, heart attack or by-pass surgery.

Benefits of taking this drug can include relief from pain, reduction of fever and inflammation, and when taken regularly in low doses it can reduce the likelihood of suffering from a heart attack or a stroke.

Listed below are the typical uses of aspirin:

  • Taken in the emergency treatment of a known or suspected heart attack.
  • Taken daily (low dose) as a blood-thinning (anti-platelet) role, which is useful for the prevention of blood clots in people who had a heart attacks or stroke. It can also be used after by-pass surgery.
  • Taken as required (high dose) for relief of mild-to-moderate pain or fever.
  • However on occasion your doctor may prescribe this medicine to treat a condition not on this list.


How often do I take it?

  • Take this medication (tablets) by mouth with a glass of water (dispersible tablets should first be dissolved in water) as required to relieve pain or fever, or regularly (usually once daily) as directed by your doctor for the prevention of heart attack and stroke. Aspirin is also available as a suppository which should be inserted rectally.
  • Check the Patient Information Leaflet and/or the label on you medicine to know exactly how to take your medicine.
  • It may take some time before the full benefit of this drug takes effect, depending on the dose given and the severity of the condition.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • Aspirin is not known to affect you ability to drive or operate machinery. Consult your doctor or pharmacist for more details.

When can I stop?

  • When used as a painkiller, aspirin should only be taken for a short-term. Speak to your doctor, if your symptoms do not improve within three days.
  • If Aspirin has been prescribed for you to take regularly, then it is important to continue taking it, unless your doctor tells you to stop.



Less commonly:

  • Irritation of the gut may lead to ulcers and bleeding into stools
  • Difficulty breathing or an asthma attack (in those with a history of these and allergic reactions).


If any of these persist or you consider them severe then inform your doctor.

Tell your doctor immediately if you develop any of the following symptoms:

  • If you vomit and it contains blood or dark particles that look like coffee grounds, passing blood in your stools or passing black tar-like stools, or severe stomach pain.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.


Before taking aspirin, tell your doctor or pharmacist if you are allergic to it; or to other non-steroidal anti-inflammatory (NSAID); or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: active stomach (peptic) ulcers or if you previously had stomach ulcers, bleeding disorders such as haemophilia, gout, or if you have had a bad reaction to aspirin or any other NSAID (you have had asthma, swelling of the lips, itchy skin or a runny nose after taking them).

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: any previous stomach (peptic) ulcers, high blood pressure, asthma, or kidney or liver problems.

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Yes. Do not drink alcohol whilst taking aspirin.

Pregnancy and breast-feeding - please ensure you read the detailed information below


Avoid aspirin in pregnancy, especially in the third trimester.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Aspirin is not safe to take if you are breastfeeding. Ask your doctor or pharmacist if you have any doubts or questions about this.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Before using this medicine, tell your prescriber of all the medicines you are taking including prescription medicines and medicines you have bought over the counter without a prescription. Tell your prescriber if you are taking vitamins or complementary remedies such as herbal products, as these can also interact with medicines.

If you are taking more than one medicine, these may interact with each other. Your prescriber may decide to use medicines which interact with each other if the benefit outweighs the risks. In these cases, the dose of your medicines may need to be adjusted or you may be monitored more closely.

The following medicines may interact with aspirin:

  • Selective serotonin reuptake inhibitors antidepressants such as fluoxetine
  • Anticoagulants (e.g. heparin or warfarin)
  • Phenytoin or sodium valproate to treat epilepsy
  • Diuretics (water tablets) e.g. spironolactone, furosemide
  • Metoclopramide or domperidone to prevent sickness
  • Probenecid, sulfinpyrazone to treat gout
  • Corticosteroids
  • Oral medication for diabetes (antihypoglycaemics)
  • Methotrexate
  • Non-steroidal anti-inflammatory drugs (NSAIDs) other than aspirin

This information does not contain all possible interactions. Therefore, tell your prescriber of all the products you are using before taking this medicine.

If you have a question or want to discuss anything about your medicine, speak to your local pharmacist.


Symptoms of an overdose include: ringing in the ears (tinnitus), deafness, dizziness, rapid breathing (hyperventilation), excessive sweating, hot hands/feet, fever or coma (unable to wake).

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of aspirin or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.


If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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Source: Selected from data included with permission and copyrighted by Boots UK Limited. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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