Allopurinol - oral

Patient Medicine Information
Why do I need this medicine?
Allopurinol is used to reduce the high level of uric acid in your body.

Build-up of uric acid in your body can cause gout, gouty arthritis, kidney or urinary tract stones. This medicine is used to prevent or treat these conditions.

This medicine may also be used to reduce high levels of uric acid that may occur during cancer treatment.
How do I take this medicine?
Take Allopurinol exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Take this medicine after meals. Try to take it at the same time each day.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the severity of your condition or your response to the medication.

Upon starting your treatment with this medicine, you may experience sudden attacks of gout. Your doctor may give you other medicines to help you cope with the pain.

Allopurinol must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Some genetic traits can increase your risk of side effects from this medicine. Individuals who have the genetic variant called HLA-B*58:01 are more likely to develop serious allergic reactions (e.g. rashes with skin peeling or blisters) to Allopurinol. Your doctor may need to perform genetic testing before giving you this medicine to know if it is suitable for you to take. If you know you have this gene type, alert your doctor.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • thyroid disease
  • undergoing treatment for heart problems or high blood pressure
  • current attack of gout
  • kidney disease
  • liver disease
Let your doctor know if you are pregnant or breastfeeding.

Be sure to check with your doctor or pharmacist before giving Allopurinol to a child or the elderly. Children or elderly people may be more sensitive to the side effects.

Ensure sufficient fluid intake while taking this medicine.

Individual's genetic traits are unique from each other. Some individuals who have an alteration in a gene called ABCG2 have reduced response to Allopurinol. Though not routinely done, in some exceptional cases, your doctor may advise you to undergo genetic testing to check if this drug is best suited for you.

Why is it important to keep my appointments with the doctor?

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
  • Routine tests (e.g. liver and kidney function, complete blood count, uric acid levels) may be done while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
  • Regular monitoring for frequency and severity of gout attacks and signs and symptoms of allergic or skin reactions and liver damage may also be needed.
What side effects could I experience?
Allopurinol may cause drowsiness, dizziness with sensations of spinning, or some problems with your coordination. If affected, do not drive or take part in any activity in which you need to be alert.

Other side effects include any of the following: nausea, vomiting, diarrhoea, fever, and weakness.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
  • rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
  • rashes, fever, tender or enlarged lymph nodes, swelling of the face
  • yellowing of the skin or eyes, abdominal pain, dark coloured urine, tiredness, swelling in the legs and ankles
  • blood in the urine, pain or difficulty when passing urine, change in how much urine is passed
Allopurinol may also cause an increase in gout attacks during the start of treatment. Let your doctor know if you experience gout attacks frequently.

This medicine may cause the level of your red blood cells, white blood cells and platelets to drop.

Red blood cells carry oxygen around your body. A fall in the level of red blood cells may make you feel tired and worn out.

White blood cells help your body to fight infections. A fall in the level of your white blood cells may put you at higher risk for infections, such as coughs, colds and flu, which may lead to more serious infections. Avoid crowded places and people who are sick. Inform your doctor if you have a fever, cough, or flu that does not go away.

Platelets help your blood to clot when there is a cut in the skin. A fall in the level of your platelets may put you at risk of bleeding more than usual. Do not take part in activities where you may fall or get injured, such as contact sports. Inform your doctor if you get any unusual bruising (large bruises or several bruises, especially if the bruises appeared on their own) or bleeding that takes a long time to stop (for example, too much bleeding when you floss or brush your teeth).

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Inform your doctor and pharmacist if you are taking any of these medicines:
  • other medicines for gout (high uric acid level in the blood) e.g. probenecid
  • aspirin (medicine for pain and inflammation)
  • medicines for cancer e.g. mercaptopurine, cyclophosphamide, bleomycin, doxorubicin
  • medicines used in organ transplants or certain immune disorders e.g. azathioprine, ciclosporin
  • certain water pills or medicines for water retention e.g. hydrochlorothiazide, indapamide, metolazone
  • certain medicines for high blood pressure e.g. captopril, enalapril
  • certain antibiotics e.g. amoxicillin, ampicillin
  • certain blood-thinning medicines e.g. warfarin
  • phenytoin (medicine for epilepsy [fits or seizures])
  • chlorpropamide (medicine for diabetes)
  • didanosine (medicine for HIV infection)
  • theophylline (asthma medicine)
  • vidarabine (medicine for eye infection)
This list does not include all medicines that may interact with Allopurinol.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements, and medicines that you buy without a prescription.
What special dietary instructions should I follow?
In order to prevent future gout attacks, it is important to be mindful of your diet.

Avoid excessive alcohol intake. Drink plenty of water to keep hydrated.

Avoid foods high in purine, such as organ meat, seafood and oily fish. Other foods with purine content, such as meat, poultry, or fish, may be eaten in moderation.

Eat a healthy and balanced diet low in highly processed foods and refined sugar (sugar that is commonly found in processed foods including soft drinks, candies, and canned fruits).
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Protect from light and moisture.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on allopurinol - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by
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