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Allopurinol 100mg

Active Ingredient:
ATC code: 
M04AA01
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About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
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Last updated on emc: 17 Jun 2025

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 28278/0035.

Allopurinol

Package Leaflet: Information for the user

Allopurinol 100 mg tablets

Allopurinol 300 mg tablets

Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.
  • Keep this leaflet. You may need to read it again.
  • If you have any further questions, ask your doctor or pharmacist
  • This medicine has been prescribed for you only. Do not pass it onto others. It may harm them, even if their symptoms are the same as yours.
  • If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See Section 4.

What is in this leaflet:

1. What Allopurinol is and what it is used for
2. What you need to know before you take Allopurinol
3. How to take Allopurinol
4. Possible side effects
5. How to store Allopurinol
6. Contents of the pack and other information

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
  • if 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.
  • if you have heart problems or high blood pressure and you take diuretics and/or a medicine called ACE-inhibitors.
  • if you are currently having an attack of gout.
  • if 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.

Allopurinol 300mg tablets contain Sunset Yellow FCF (azo colouring agent) and should not be given to children.

Other medicines and Allopurinol

Tell your doctor or pharmacist if you are taking any of the following medicines:

  • 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 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.
  • 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.

If aluminium hydroxide is taken concomitantly,allopurinol may have an attenuated 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 disorders (dyscrasias) occur more frequently than when these medicines are administered alone.

Blood count monitoring should therefore be performed at regular intervals.

Please tell your doctor or pharmacist if you are taking or have recently taken 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. This medicine during breast-feeding is not recommended.

Driving and using machines

You may feel drowsy, giddy or have problems with your coordination. 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 medicine.

Allopurinol 300 mg tablets contain Sunset yellow FCF (E110). Sunset yellow FCF (E110) may cause allergic reactions.

Allopurinol contains sodium

This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium free’

3. How to take Allopurinol

Always take this medicine exactly as your doctor has told you. You should check with your doctor or pharmacist if you are not sure.

Take the tablet after food and swallow it with a glass of water.

The score line is only there to help you break the tablet if you have difficulty swallowing it whole.

The recommended dose ranges from 100 to 900 mg each day. You will usually start on a low dose, which will be increased if necessary.

If you are an older person or if you have reduced liver or kidney function, your doctor may prescribe a lower dose or to take it at longer intervals. 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.

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.

Use in children (under 15 years)

The usual dose ranges from 100 to 400 mg each day.

If you take more Allopurinol than you should

If you take more Allopurinol than you should, contact 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 this medicine 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.

The following side effects may happen with this medicine:

Hypersensitivity

Uncommon (may affect less than 1 in 100 people)

If you have a hypersensitivity (allergic) reaction, stop taking this medicine and see a doctor straightaway. 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 less than 1 in 1,000 people)

  • fever and chills, headache, aching muscles (flu-like symptoms) and generally feeling unwell
  • serious hypersensitivity reactions involving 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.
  • effect on 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(can not be estimated from available data):

  • Lichenoid skin rash (itchy reddish-purple skin rash and/or threadlike white-grey lines on mucous membranes)
  • 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.

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 at: 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 after 'EXP'. The expiry date refers to the last day of that month.

Keep your tablets in the original packaging.

This medicine does not require any special storage conditions.

Do not throw away any medicines via wastewater or household waste.

Return any unused or unwanted tablets to your pharmacist for disposal. Only keep them if your doctor tells you to. These measures will help protect the environment.

6. Contents of the pack and other information
What Allopurinol contains
  • Allopurinol 100 mg tablets contains:
    • The active substance is allopurinol.
    • The other ingredients are lactose monohydrate , maize starch, povidone, sodium starch glycolate (Type A), maize starch (dried), stearic acid.
  • Allopurinol 300 mg tablets contains:
    • The active substance is allopurinol.
    • The other ingredients are lactose monohydrate, maize starch, color sunset yellow FCF Al. lake (E110) , povidone, sodium starch glycolate (Type A), maize starch (dried), stearic acid

What Allopurinol looks like and contents of the pack

Allopurinol 100 mg tablets: white to off-white, approx 7.5 mm round, biconvex, uncoated tablets with 'AL' & '100' separated by breakline on one side & plain on other side.

Allopurinol 300 mg tablets: peach colored, approx 11mm round, biconvex, uncoated tablets with 'AL' & '300' separated by breakline on one side & plain on other side.

Allopurinol 100 mg and 300 mg are supplied in PVDC coated PVC/Aluminium Blister with pack sizes of 10’s , 28’s, 30’s , 50’s ,70’s , 90’s.

Marketing Authorisation Holder and Manufacturer
Ipca Laboratories UK Ltd.
Unit 97-98
Silverbriar
Sunderland Enterprise Park East
Sunderland
SR5 2TQ
United Kingdom
Telephone: +44 (0) 1915166517
Fax: +44 (0) 1915166526

Manufacturer
Elara Pharmaservices Limited
Iron Farm
7 Grimes Gates
Diseworth
DE74 2QD,
United Kingdom

This leaflet was last revised in 05/2025.

Ipca Laboratories UK Ltd
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Address
Silverbriar, Enterprise Park East, Sunderland,, Tyne and Wear, SR5 2TQ, UK
Telephone
+44 (0)7546 801 411
Fax
+44 (0) 191 516 6 526
Medical Information Direct Line
08003685328
Medical Information e-mail
[email protected]
Customer Care direct line
08003685328
Stock Availability
+44(0)7546 801 411