Allopurinol treats gout or kidney stones by reducing uric acid in the body. It may also be used to decrease uric acid levels in people undergoing cancer treatment.

Take medicine with full glass of water. Take with food if medicine upsets stomach. You may need to follow a special diet. You may experience more gout attacks when starting allopurinol.

Avoid driving and activities that require alertness until you know how this drug affects you. Avoid alcohol.

Get emergency help and inform doctor if you experience serious effects. This includes: allergic reaction, serious skin reaction, rash (even mild), painful urination or bloody urine, joint pain, easy bruising, flu-like symptoms, little/no urination, numbness, worsening gout symptoms, liver issues (jaundice, weight loss, etc.) Other common side effects include: drowsiness, rash, abnormal liver test results, nausea and vomiting, headache, change in taste perception. Allopurinol may iteract with: azathioprine/mercaptopurine, chlorpropamide, cyclosporine, antibiotics, blood thinners, diuretics, OTC drugs, herbs/vitamins/supplements