How does allopurinol work?
Allopurinol blocks an enzyme called xanthine oxidase, which helps produce uric acid. By lowering uric acid levels, it prevents the formation of urate crystals that cause gout attacks and kidney stones.
What is allopurinol used to treat?
Allopurinol is commonly prescribed for:
- Gout (to prevent flare-ups)
- Kidney stones (caused by high uric acid levels)
- Preventing uric acid buildup in people undergoing chemotherapy
Who can take allopurinol?
Allopurinol is suitable for most adults and some children, particularly those with recurrent gout or kidney stones.
Who might not be able to take allopurinol?
Allopurinol may not be suitable if you:
- Have liver or kidney disease
- Have had a severe allergic reaction to allopurinol before
- Are currently experiencing a gout attack (as starting allopurinol can sometimes worsen a flare-up)
Can I take allopurinol if I’m pregnant or breastfeeding?
Allopurinol isn’t usually recommended during pregnancy or while breastfeeding unless advised by a doctor.
What if I miss a dose?
If you forget a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed one—do not take two doses at once.
How effective is allopurinol?
Allopurinol is highly effective at lowering uric acid levels and preventing gout attacks when taken consistently. However, it may take several weeks to reach full effectiveness.
What should I do if I take too much?
Taking too much allopurinol can cause nausea, vomiting, dizziness, or liver problems. If you think you’ve taken too much, seek medical help immediately.
What dose of allopurinol is usually taken?
- For gout prevention: 100mg to 300mg once daily, adjusted as needed
- For kidney stones or chemotherapy-related uric acid buildup: Dose varies depending on condition
Your doctor will determine the best dose based on your uric acid levels.
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What are the side effects of allopurinol?
Common side effects include:
- Nausea or diarrhoea
- Skin rash (if severe, seek medical attention immediately)
- Drowsiness
- Changes in liver function (usually detected in blood tests)
Serious side effects, such as severe allergic reactions (Stevens-Johnson syndrome), require urgent medical attention.
How should I take allopurinol?
Allopurinol is taken as a tablet, once daily, usually with food to reduce stomach upset.
When should allopurinol be taken?
Allopurinol is best taken after a meal, at the same time each day.
What are the brand names for allopurinol?
Allopurinol is available as a generic medicine, but some branded versions include:
- Zyloric
Final thoughts
Allopurinol is an effective treatment for preventing gout and kidney stones, but it should be taken consistently to work properly. If you experience side effects or are unsure about your dose, speak to your doctor or pharmacist.
