Patient leaflet - Allopurinol 300 mg tablets
1. WHAT ALLOPURINOL IS AND WHAT IT IS USED FOR
Allopurinol tablets contain a medicine called allopurinol. It works by slowing down the speed of certain chemical reactions in your body to lower the level of uric acid in the blood and urine.
Allopurinol is used to reduce or prevent the formation of urate/uric acid deposition in conditions where your body produces too much of a substance called uric acid. These may include gout or some types of kidney stones or certain other types of kidney problems or when you are having treatment for cancer or some other conditions. In gout the uric acid builds up in your joints and tendons as crystals. These crystals cause an inflammatory reaction. The inflammation causes the skin around certain joints to become swollen, tender and sore when only slightly touched. You can also find you get severe pain when the joint is moved.
2. WHAT YOU NEED TO KNOW BEFORE YOU TAKE ALLOPURINOL
Do not take Allopurinol
if you are allergic (hypersensitive) to allopurinol or any of the other ingredients of this medicine (listed in section 6).
If you are not sure, talk to your doctor or pharmacist before taking Allopurinol.
Warnings and precautions
Talk to your doctor or pharmacist before taking your medicine if: you are of Han Chinese, African or Indian origin
you have problems with your liver or kidneys. Your doctor may give you a lower dose or ask you to take it less often than each day. They will also monitor you more closely.
you have heart problems or high blood pressure and you take diuretics and/or a medicine called ACE-inhibitors
you are currently having an attack of gout
you have thyroid problems
Take special care with Allopurinol:
Serious skin rashes (Hypersensitivity syndrome, Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported in patients taking allopurinol. Frequently, the rash can involve ulcers of the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). These serious skin rashes are often preceded by influenza-like symptoms fever, headache, body ache (flu-like symptoms). The rash may progress to widespread blistering and peeling of the skin. These serious skin reactions can be more common in people of Han Chinese, Thai or Korean origin. Chronic kidney disease may increase the risk in these patients additionally. If you develop a rash or these skin symptoms, stop taking allopurinol and contact your doctor immediately. If you have cancer or Lesch-Nyhan syndrome the amount of uric acid may increase in your urine. To prevent this, you need to assure to drink sufficiently to dilute your urine.
In case you have kidney stones, the kidney stones will become smaller and may enter your urinary tract.
Children
Use in children is rarely indicated, except in some types of cancer (especially leukaemia) and certain enzyme disorders such as Lesch-Nyhan syndrome.
Other medicines and Allopurinol
Tell your doctor or pharmacist if you are taking any of the following: aspirin
theophylline, used for breathing problems
medicines used for fits (epilepsy), phenytoin
vidarabine, used to treat herpes or chickenpox
antibiotics (ampicillin or amoxicillin)
didanosine, used to treat HIV infection
medicines used for cancer
medicines used to reduce your immune response
(immunosuppressants)
medicines used to treat diabetes
medicines used for heart problems or high blood pressure such as ACE inhibitors or water tablets (diuretics)
medicines used to thin your blood (anticoagulants), such as warfarin any other medicine to treat gout
If aluminium hydroxide is taken concomitantly, allopurinol may have reduced effect. There should be an interval of at least 3 hours between taking both medicines.
With administration of allopurinol and cytostatics (e.g. cyclophosphamide, doxorubicin, bleomycin, procarbazine, alkyl halogenides), blood dyscrasias occur more frequently than when these active substances are administered alone. Blood count monitoring should therefore be performed at regular intervals.
It is especially important to tell your doctor if you are taking any of the medicines listed below. Your doctor may need to reduce the dose of your medicine and/or monitor you more carefully because of the increased risk of side effects when Allopurinol is taken at the same time as: 6-Mercaptopurine (used to treat blood cancer)
Azathioprine (used to suppress the immune system) The co-administration of 6-mercaptopurine or azathioprine with allopurinol should be avoided. When 6-mercaptopurine or azathioprine is given concurrently with Allopurinol, the dose of 6-mercaptopurine or azathioprine should be reduced because their activity will be prolonged. This could increase the risk of serious blood disorders. In this case, your doctor will closely monitor your blood count during treatment. Seek medical advice immediately if you notice that you have any unexplained bruising, bleeding, fever or sore throat.
Please tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes medicines obtained without a prescription, including herbal medicines. This is because Allopurinol can affect the way some medicines work. Also some other medicines can affect the way Allopurinol works.
Pregnancy and breast-feeding
Talk to your doctor before taking this medicine if you are pregnant, might become pregnant or are breast-feeding. Allopurinol is excreted in the human breast milk. Allopurinol during breastfeeding is not recommended. Driving and using machines
You may feel drowsy, giddy or have problems with your co-ordination. If this happens, do not drive or use any tools or machines. Allopurinol contains lactose
If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.
3. HOW TO TAKE ALLOPURINOL
Always take Allopurinol exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.
Taking this medicine
Swallow the tablet with a drink of water.
Take tablets just after a meal.
Your doctor will usually start with a low dose of allopurinol (e.g. 100 mg/ day), to reduce the risk of possible side effects. Your dose will be increased if necessary.
The recommended dose is:
Adults (over 18 years)
The usual dose ranges from 100 to 900 mg each day.
Children (under 15 years)
The usual dose ranges from 100 to 400 mg each day. Elderly (over 65 years)
Your doctor will prescribe the lowest dose of Allopurinol tablets that best controls your symptoms.
(Continued overleaf) Package leaflet: Information for the user Allopurinol 100 mg
Tablets Allopurinol 300 mg
Tablets
allopurinol
As stated in design Package leaflet
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TW271699 (launch)
UK
All
NA
TBA
9 pts (Reg text)
TW265767 13/07/2026 20/07/2026 03/09/2026 21/09/2026
Black C
Also TW283482
If you have a serious kidney problem
you may be asked to take less than 100 mg each day or you may be asked to take 100 mg at longer intervals than one day. If you have dialysis two or three times a week, your doctor may prescribe a dose of 300 or 400 mg which is to be taken straight after your dialysis. If you take more Allopurinol than you should
If you take more Allopurinol than you should, talk to a doctor or go to hospital straight away. Take the medicine pack with you. Signs of an overdose may include nausea, vomiting, diarrhoea and dizziness. If you forget to take Allopurinol
If you forget a dose, take it as soon as you remember it. However, if it is nearly time for the next dose, skip the missed dose.
Do not take a double dose to make up for a forgotten dose. If you stop taking Allopurinol
Do not stop taking your Allopurinol without talking to your doctor. If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
4. POSSIBLE SIDE EFFECTS
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Serious side effects
If you experience any of the following, stop your tablets and seek immediate medical attention:
Hypersensitivity
Uncommon (may affect up to 1 in 100 people)
If you have a hypersensitivity (allergic reaction), stop taking Allopurinol and see a doctor straight away. The signs may include: flaking skin, boils or sore lips and mouth
very rarely signs may include sudden wheeziness, fluttering or tightness in the chest and collapse.
Rare (may affect up to 1 in 1000 people)
fever and chills, headache, aching muscles (flu-like symptoms) and generally feeling unwell
serious hypersensitivity reactions including fever, skin rash, joint pain and abnormalities in blood and liver function tests (these may be signs of a multi-organ sensitivity disorder)
bleeding in the lips, eyes, mouth, nose or genitals
any changes to your skin, for example; ulcers of the mouth, throat, nose, genitals, conjunctivitis (red and swollen eyes), widespread blisters or peeling
Very rare (may affect up to 1 in 10 000 people)
Serious allergic reaction which causes swelling of the face or throat Serious potentially life-threatening allergic reaction Do not take any more tablets unless your doctor tells you to do so. Other side effects
Common (may affect up to 1 in 10 people)
skin rash
increased level of thyroid stimulating hormone in the blood Uncommon (may affect up to 1 in 100 people)
feeling sick (nausea) or being sick (vomiting)
abnormal liver tests
diarrhoea.
Rare (may affect up to 1 in 1 000 people)
liver problems such as liver inflammation
Very rare (may affect up to 1 in 10 000 people)
Occasionally Allopurinol tablets may affect your blood, which can manifest as bruising more easily than usual, or you may develop a sore throat or other signs of an infection. These effects usually occur in people with liver or kidney problems. Tell your doctor as soon as possible.
Allopurinol may affect the lymph nodes
high temperature
blood in your urine (haematuria)
high levels of cholesterol in your blood (hyperlipidaemia) a general feeling of being unwell or feeling weak
weakness, numbness, unsteadiness on your feet, feeling unable to move muscles (paralysis) or loss of consciousness headache, dizziness, drowsiness or disturbance of your vision chest pain (angina), high blood pressure or a slow pulse male infertility or erectile dysfunction
enlargement of the breasts, in men as well as women a change in your normal bowel habit
a change in taste
cataracts
hair loss or discolouration
depression
lack of voluntary coordination of muscle movements (ataxia) sensation of tingling, tickling, pricking or burning of skin (paraesthesia) build up of fluid leading to swelling (oedema) particularly of your ankles abnormal glucose metabolism (diabetes). Your doctor may wish to measure the level of sugar in your blood to check if this is happening Not known (cannot be estimated from available data)
Aseptic meningitis (inflammation of the membranes that surround the brain and spinal cord): symptoms include neck stiffness, headache, nausea, fever or consciousness clouding. Seek medical attention immediately if these occur.
Lichenoid skin rash (itchy reddish-purple skin rash and/or threadlike white-grey lines on mucous membranes)
If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist. Reporting of side effects
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme website:
www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.
5. HOW TO STORE ALLOPURINOL
Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the carton and blister after ‘EXP’. The expiry date refers to the last day of that month.
This medicinal product does not require any special storage conditions. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment.
6. CONTENTS OF THE PACK AND OTHER INFORMATION
What Allopurinol contains
The active substance is allopurinol.
The other ingredients are lactose monohydrate, maize starch, povidone and magnesium stearate.
What Allopurinol looks like and contents of the pack
Allopurinol tablets contains 100 or 300 mg allopurinol.
Each 100 mg tablets are white to off white, scored, flat cylindrical tablet debossed with ‘I’ and ‘56’ on either side of the break line on one side and plain on other side with diameter approx. 8.0 mm.
Each 300 mg tablets are white to off white, scored, flat cylindrical tablet debossed with ‘I’ and ‘57’ on either side of the break line on one side and plain on other side with diameter approx. 11.0 mm.
The score line is only to facilitate breaking for ease swallowing and not to divide into equal doses.
Allopurinol 100 mg and 300 mg tablets are packed in PVC/Alu foil blister pack.
Pack size: 28, 30, 50, 56 and 100 tablets.
Not all pack sizes may be marketed.
Marketing Authorisation Holder
Tillomed Laboratories Limited
220 Butterfield, Great Marlings
Luton, LU2 8DL, United Kingdom
Manufacturer
Tillomed Laboratories Limited
220 Butterfield, Great Marlings
Luton, LU2 8DL, United Kingdom
Tillomed Malta Limited
Malta Life Sciences Park
LS2.01.06 Industrial Estate
San Gwann, SGN 3000, Malta
Other formats
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This leaflet was last revised in September 2026
2015446