- What is allopurinol, and how does it work (mechanism of action)?
- What brand names are available for allopurinol?
- Is allopurinol available as a generic drug?
- Do I need a prescription for allopurinol?
- What are the uses for allopurinol?
- What are the side effects of allopurinol?
- What is the dosage for allopurinol?
- Which drugs or supplements interact with allopurinol?
- Is allopurinol safe to take if I'm pregnant or breastfeeding?
- What else should I know about allopurinol?
What is allopurinol, and how does it work (mechanism of action)?
Allopurinol is used for treating gout caused by excessive levels of uric acid in the blood (hyperuricemia). It is a xanthine oxidase inhibitor and is similar to febuxostat (Uloric). Uric acid is a by product from the breakdown of certain proteins (purines) in the body by enzymes called xanthine oxidases. Hyperuricemia occurs when the body produces more uric acid than it can eliminate. The uric acid forms crystals in joints (gouty arthritis) and tissues, causing inflammation and pain. Elevated blood uric acid levels also can cause kidney disease and kidney stones. Allopurinol prevents the production of uric acid by blocking the activity of the enzymes that converts purines to uric acid. Uric acid levels usually begin to fall within 2-3 days of starting treatment and return to their original levels within 7-10 days after allopurinol is stopped. It may take several months of therapy before attacks of gout are controlled. The FDA approved allopurinol in August 1966.
What are the uses for allopurinol?
Allopurinol is used for preventing and/or treating acute attacks of gout, erosive destructive gouty joint disease, uric acid deposits in tissues (tophi), gouty kidney disease, and uric acid stones. Allopurinol also is used to prevent elevation of blood uric acid in patients undergoing chemotherapy for the treatment of certain cancers and in patients with recurrent calcium kidney stones and elevated uric acid levels.
What is the dosage for allopurinol?
The dose of allopurinol for treating gout is 200-600 mg daily depending on severity. The dose for treating high uric acid blood levels due to chemotherapy is 100-800 mg daily starting 1 or 2 days before chemotherapy. It should be taken with food to avoid irritation of the stomach. In order to avoid formation of kidney stones, patients should drink plenty of fluids while taking allopurinol.
Which drugs or supplements interact with allopurinol?
: Allopurinol increases blood levels of oral mercaptopurine (Purinethol) and azathioprine (Imuran) by reducing their breakdown in the body. Therefore, the dose of mercaptopurine and azathioprine should be reduced in order to avoid toxicity. There is an increased risk of skin rash in patients taking allopurinol in combination with penicillins. Allopurinol may increase the effect of warfarin by reducing its breakdown.
Is allopurinol safe to take if I'm pregnant or breastfeeding?
There are no adequate studies of allopurinol in pregnant women.
What else should I know about allopurinol?
What preparations of allopurinol are available?
Tablets: 100, 300 mg; Powder for injection: 500 mg
How should I keep allopurinol stored?
Tablets should be stored at room temperature between 15 C to 25 C (59 F to 77 F) and in a moisture proof, light- resistant container. Powder should be stored from 20 C to 25 C (68 F to 77 F) and not refrigerated.
Quick GuideGout Attack Symptoms, Causes, Treatment, and Diet
Multimedia: Slideshows, Images & Quizzes
Gout Quiz: What is Gout? Is There a Gout Diet?
Learn what causes those painful crystals to form during a gout flare. Take the Gout Quiz to learn all about this painful...
Picture of Gout
Condition characterized by abnormally elevated levels of uric acid in the blood, recurring attacks of joint inflammation...
Picture of Fixed Drug Eruption
A large red-violet plaque on the arm of a child. See a picture of Fixed Drug Eruption and learn more about the health topic....
Gout Attack Symptoms, Causes, Treatment, and Diet
Gout attacks (gouty arthritis) are caused by crystals of uric acid deposits. Learn about symptoms, causes, treatments and...
Related Disease Conditions
Kidney Stones (nephrolithiasis)
Kidney stones are solid masses of crystalline material that form in the kidneys. Symptoms of kidney stones can include pain,...
Gout (Gouty Arthritis)
Buildup of uric acid crystals in a joint causes gouty arthritis. Symptoms and signs include joint pain, swelling, heat, and...
Treatment & Diagnosis
- Gout FAQs
- Medication Disposal
- Dangers of Mixing Medications
- Prescriptions: Complying with the Doctor's Orders
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
Prevention & Wellness
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.