Allopurinol (Zyloprim, Aloprim)
Allopurinol is a medication that lowers your risk of gout attacks by lowering uric acid in your blood. If you keep the uric acid level in your blood 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 allopurinol, and your provider may check a genetic marker (HLA- B5801) before starting this medication.
Side Effects
Allopurinol may cause an allergic reaction. This is usually very mild but can be serious. Serious allergic reactions to allopurinol are rare. If you notice itchy skin, new rash, or hives, you should stop allopurinol and call your provider.
If you have kidney disease or you 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
It may not be safe to take allopurinol if you are taking transplant or cancer medications, such as (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 2025 by Rebecca Manno, MD, MHS, 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.