Allopurinol 100 mg tablets – patient leaflet, side effects, dosage

1. What Allopurinol is and what it is used for

Allopurinol contains allopurinol.

tablets a medicine called 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 to allopurinol or any of the other ingredients of this medicine

  (listed in Section 6).

  Allopurinol If you are not sure, talk to your doctor or pharmacist before taking .

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

• In case you have kidney stones, the kidney stones will become smaller and may

  enter your urinary tract.

• 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.

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
• 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.

• 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.

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 dyscrasias occur more frequently than when these active substances 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 Allopurinol is excreted in the human breast milk.

breast-feeding.

Allopurinol during breastfeeding is not recommended.

Driving and using machines

You may feel If this

drowsy, giddy or have problems with your coordination. 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

You should your doctor or pharmacist if you are not sure.

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

The 100 to 900 mg each day.

recommended dose ranges from 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.

UK (Unit-V) Allopurinol 100 mg/ 300 mg tablets Leaflet

Supersede: 2090667

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 , ask your doctor or

product 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 Allopurinol and see a doctor straight way. 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 1000 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 1000 people)

• liver problems such as liver inflammation.

Very rare (may affect up to 1 in 10,000 people)

• 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

• abnormal glucose metabolism (diabetes). Your doctor may wish to measure the

  level of sugar in your blood to check if this is happening.

• 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
• 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

Not known (cannot 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, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via 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 blister and the carton. The expiry date refers to the last day of that month.

Store below 25°C.

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 protect the environment.

6. Contents of the pack and other information

What Allopurinol contains

The active substance is allopurinol

Each tablet contains 100 mg allopurinol.

Each tablet contains 300 mg allopurinol.

The other ingredients are:

Lactose monohydrate, maize starch, crospovidone, povidone and magnesium stearate.

What Allopurinol looks like and contents of the pack

Allopurinol 100 mg tablets

White to off-white colored, 7.80 mm round tablets debossed with "U" and "5" on one side and scoreline with "H" on the other side.

The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.

Allopurinol 300 mg tablets

White to off-white colored, 11.10 mm round tablets debossed with "U" and "6" on one side and scoreline with "H" on the other side.

The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.

Blister containing 28 and 100 tablets.

Not all pack sizes may be marketed.

Marketing Authorisation Holder and Manufacturer

Amarox Limited

Congress House, 14 Lyon Road

Harrow, HA1 2EN

United Kingdom

This leaflet was last revised in 08/2026.

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