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Terms Of Use


Brand Name(s) : Zyloric, Caplenal, Cosuric, Rimapurinol
Side Effects


Allopurinol should be used with caution in:

It should not be used in:

  • Patients who have an allergy (hypersensitivity) to allopurinol or any of the other ingredients
  • Patients who are having an acute attack of gout and are not already taking allopurinol.

Also see list of precautions and interactions.


Store below 25°C in the original packaging.


What is it used for?

  • Allopurinol is used to treat conditions caused by high levels of uric acid in the blood.
  • It is a xanthine oxidase inhibitor, sometimes known as an anti-gout drug.
  • It is used to reduce the levels of uric acid in the blood that can cause gout, kidney disease and kidney stones by inhibiting an enzyme in the liver that converts another compound (xanthine) to uric acid.
  • In general this drug is used if you have high levels of uric acid in the blood. The uric acid can build up in the body as crystals in the joints, tendons and kidneys. In the joints and tendons these crystals can cause an inflammatory reaction, and joints may become swollen, tender and sore when only slightly touched or when you move. Uric acid crystals in the kidney may cause kidney stones or other kidney problems. Allopurinol should never be started during an acute attack and is usually started few weeks after the attack has settled.
  • Benefits of being on this drug can include reduced levels of uric acid in the blood, preventing acute attacks of gout. It is also used to prevent other conditions where there is a build-up of uric acid in the kidney (e.g. kidney stones or as an effect of some medicines used in treating cancer).

Listed below are the typical uses of allopurinol.

  • Conditions where high levels of uric acid has already built up, including gouty arthritis, skin tophi (crystals of uric acid forming under the skin), and formation of kidney stones (nephrolithiasis)
  • Conditions where uric acid build-up is likely (e.g. during treatment of cancer with chemotherapies that may lead to kidney damage owing to high uric acid levels)
  • Enzyme disorders that lead to an over-production of uric acid.

On occasion your doctor may prescribe this medicine to treat a condition not on the above list.


p> How often do I take it?
  • Take this medication orally with water after food.
  • Use this medication regularly in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told otherwise by your doctor.
  • 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?

  • You may feel drowsy, dizzy, or have problems with your co-ordination. If this happens, do not drive or operate machinery. Consult your doctor or pharmacist for more details.

When can I stop?

  • It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop.


If any of these persist or you consider them severe then stop taking allopurinol and inform doctor or pharmacist.

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

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 allopurinol, tell your doctor or pharmacist if you are allergic to it; or to other gout medications; 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: an allergy (hypersensitivity) to allopurinol or any of the other ingredients, if you are having an acute attack of gout and are not already taking allopurinol.

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: pregnancy, breastfeeding, liver or kidney problems, heart problems, high blood pressure, or sugar intolerance.

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

Does alcohol intake affect this drug?

  • Alcohol intake is not known to affect allopurionol.

The elderly: allopurinol should be used with caution in the elderly. You should use the lowest possible dose that reduces uric acid levels.

Pregnancy and breastfeeding - please ensure you read the detailed information below.


The safety of allopurinol has not been established during pregnancy. Ask your doctor or pharmacist if you have any doubts or questions about this.

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.


The safety of allopurinol has not been established in breastfeeding.

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 allopurinol:

  • Didanosine used to treat HIV infections
  • Aspirin or related medicines (salicylates)
  • Theophylline, used for asthma and breathing problems
  • Phenytoin and carbamazepine, used for fits (epilepsy)
  • Ampicillin or amoxicillin (antibiotics used to treat bacterial infections)
  • Didanosine, used to treat HIV infections
  • Medicines for cancer such as azathioprine, mercaptopurine, capecitabin, pentostatin or cyclophosphamide
  • Medicines used to reduce your immune response (immunosuppressants) such as ciclosporin
  • Medicines used to treat diabetes (chlorpropamide or tolbutamide)
  • Medicines for heart problems or high blood pressure such as angiotensin-converting enzyme (ACE) inhibitors (e.g. captopril)
  • Medicines used to thin your blood (anti-coagulants), such as dicoumarol, phenprocoumon and warfarin
  • Any other medicine to treat gout, such as probenecid
  • Adenine arabinoside (an antiviral medicine)
  • Thiazide diuretics (medicines used to get rid of excess fluid from the body, sometimes called water tablets)
  • Medicines used to treat problems with stomach acid (e.g. aluminium hydroxide)

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.


If you take more allopurinol than you should then you should contact your nearest hospital emergency department or your doctor immediately.

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of allopurinol 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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