Allopurinol (Zyloprim, Aloprim)


Allopurinol is a medication that lowers your risk of gout attacks. It lowers uric acid in your blood. If you keep the uric acid level low, the uric acid crystals in and around your joints that cause gout attacks begin to go away. When you start allopurinol, the risk of gout attacks may go up before it comes down. You can lower this risk by starting with a low dose of allopurinol or taking anti-inflammatory medications like colchicine or NSAIDs.

How To Take It

Take allopurinol in the morning with food and water. Some patients (those of Southeast Asian or African descent) may have a genetic predisposition to allergic reactions to the allopurinol in this medication, and your provider may check a genetic marker (HLA- B5801) before starting.

Side Effects

The most common side effect from allopurinol is an allergic reaction. This is usually mild but can be serious (or even deadly). A serious allergic reaction is rare. If you notice itchy skin, new rash, or hives, you should stop allopurinol and call your provider.

If you have kidney disease or are Asian or Black, you may have a higher risk of serious reaction. Your doctor can test for risk of allergic reaction by checking a blood test (HLA-B*5801).

Allopurinol is safe to use in chronic kidney disease, but your starting dose should be lower than normal.

Tell Your Rheumatology Provider

Tell your gout provider if you have a history of liver or kidney disease. Tell your gout provider if you had a reaction to allopurinol.

It may not be safe to take allopurinol if you are taking transplant or cancer medication (azathioprine or 6-mercaptopurine).

If you are pregnant or may get pregnant, let your doctor know before starting this medication. Women should discuss birth control with their primary care physicians or gynecologists. Breast-feeding should be avoided while taking allopurinol. The risk in pregnancy and breastfeeding has not been determined.

Updated February 2024 by Howard Yang, MD, John Fitzgerald MD, PhD, Chen Xie, MD, and reviewed by the American College of Rheumatology Communications and Marketing Committee.

This information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis, and treatment of a medical or health condition.

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