How does allopurinol work?
Allopurinol works by reducing the amount of uric acid made by body cells.
If you have gout, it helps prevent uric acid crystals building up in the joints, which makes them swollen and painful.
It is also used to support some cancer treatments. Such treatments kill cancer cells but uric acid is then released from these cells. The build-up of uric acid into crystals can damage the kidneys.
Allopurinol can also help to treat kidney stones, when the waste products in the blood (including uric acid) make crystals that collect inside the kidneys.
Allopurinol reduces the symptoms caused by the build-up of uric acid in these conditions.
When will I feel better?
Allopurinol does not work straight away. It may take several weeks to reduce the level of uric acid. You may have more gout attacks for some time after starting allopurinol.
Are there any long-term side effects?
Allopurinol is considered very safe to take for a long period of time. There are unlikely to be any long-term effects.
What will happen if I stop taking it?
If you stop allopurinol treatment suddenly, there's a high risk that your gout may get worse or you'll get serious side effects.
Only stop taking allopurinol if a doctor tells you to. A doctor will help you to reduce your dose slowly so you do not get serious side effects.
Are there any other medicines for gout?
There are 2 types of medicines used for gout treatment – some stop the gout attack and some prevent further gout attacks.
Medicines that treat an attack of gout include:
- diclofenac
- etoricoxib
- indomethacin
- ketoprofen
- naproxen
- sulindac
- colchicine
- steroids
- canakinuma
Medicines that treat gout long-term in a similar way to allopurinol include:
- febuxostat
- sulfinpyrazone
- benzbromarone
What happens if I take allopurinol when I'm having cancer treatment?
Some cancer treatments can cause an increase in uric acid levels in the blood which can then trigger gout attacks. Allopurinol should be started before these particular cancer treatments to prevent the build-up of uric acid.
However, some cancer treatments can cause changes in the blood which can be made worse if you take allopurinol. Your doctor will monitor you carefully and take blood tests if you are at risk.
What effect does allopurinol have on the kidneys and liver?
It's rare for allopurinol to affect the liver or kidneys.
However, if you have serious problems with your kidneys then you may be at greater risk of an allergic reaction to allopurinol. A doctor may prescribe a lower dose of allopurinol.
Allopurinol can also inflame the liver.
Will it affect my sex life?
Allopurinol is not commonly known to affect sex.
However, rarely it can cause breasts to get larger (in both men and women) or erection problems (erectile dysfunction).
Talk to a doctor if you get any of these symptoms.
Will it affect my contraception?
Allopurinol does not affect any type of contraception including the combined pill or emergency contraception.
But if allopurinol makes you vomit, your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.
Find out more:
Can I drive or ride a bike?
Some people may feel sleepy when taking allopurinol.
Do not drive a car, ride a bike, or operate machinery if allopurinol makes you feel sleepy or unable to concentrate or make decisions. This may be more likely when you first start taking allopurinol, but could happen at any time – for example, when starting another medicine.
It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
Talk to a doctor or pharmacist if you're unsure whether it's safe for you to drive while taking allopurinol. GOV.UK has more information on the law on drugs and driving.
Is there any food and drink I need to avoid?
There are no foods or drink you need to avoid while taking allopurinol. However, drinking alcohol can trigger an attack of gout.
Reducing certain types of food and drink may help to stop gout coming back. It's a good idea not to have too much:
- red meat, kidneys, liver, or seafood
- sugary drinks and snacks
- fatty foods
- alcohol
Can I drink alcohol while taking allopurinol?
Yes, you can drink alcohol while taking allopurinol. Alcohol does not affect how this medicine works.
However, drinking alcohol increases the level of uric acid in your blood. This can trigger an attack of gout or make it worse.
It's best to stick to the national guidelines of no more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units. A pint of lager or beer is usually 2 to 3 units of alcohol.
Can lifestyle changes help gout?
There are lifestyle changes you can make to help stop getting further attacks of gout or reduce the chance of it returning:
- make sure you're a healthy weight
- eat well – cut saturated fat and increase fibre, fruits, vegetables, wholegrains and fish
- quit smoking
- cut down on alcohol
- try to exercise every day