Allopurinol
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Taken as tablets, usually once a day after a meal (a larger daily dose is split into smaller doses). Drink plenty of fluid. When you first start, you are often given a short course of another medicine (such as colchicine) to prevent gout flares, because lowering uric acid can trigger a flare at first. It works gradually over weeks.
- Gout (urate lowering): Started at a low dose and slowly increased until your uric acid reaches the target range.
Uric acid usually reaches a normal level within 1 to 3 weeks, and the dose is adjusted from blood tests.
Tests while you take it
Blood tests to check your uric acid guide the dose. Stop the tablets and get medical help urgently if you develop any skin rash, because rare but serious skin and allergic reactions can occur, especially in the first weeks.
What to know
How it is used in gout
Allopurinol is the first medicine most people are given to lower uric acid, because it works well, is taken once a day, and is low cost. It is suitable even for people with kidney problems. It is a long-term medicine.
Before starting
Some people are offered a blood test before starting, to check for a gene that raises the risk of a serious skin reaction. Your team will tell you if this applies to you based on your background.
Monitoring
Your uric acid is checked with blood tests, more often while the dose is being increased and then to make sure it stays below target. Your kidneys are also kept in view.
Common effects
Most people tolerate allopurinol well. Some notice a rash or stomach upset. When you first start, attacks can happen more often for a while, which is why a second medicine is given alongside it for a few months.
Important cautions
Stop and seek medical advice urgently if you develop a rash, especially with fever, mouth sores, or peeling skin, as this can be a serious reaction. Tell every prescriber you take allopurinol, particularly if you also take azathioprine or mercaptopurine, because the combination needs special care.
What to watch for
- A rash, especially with fever, mouth sores, or peeling skin, after starting allopurinol. This can be a serious reaction and needs urgent medical attention.
- More frequent gout attacks in the first weeks. This is expected and is why a preventive medicine is given alongside; tell your team if attacks are severe.
- If you also take azathioprine or mercaptopurine, make sure every prescriber knows you are on allopurinol.