DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.This drug should not be used with the following medication because very serious interactions may occur: didanosine.If you are currently using this medication, tell your doctor or pharmacist before starting allopurinol.Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: certain asthma drugs (aminophylline, theophylline), azathioprine, "blood thinners" (e.g., warfarin), chlorpropamide, cyclosporine, mercaptopurine, "water pills" (e.g., thiazide diuretics such as hydrochlorothiazide).This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center.

NOTES: Do not share this medication with others.Laboratory and/or medical tests (e.g., uric acid blood levels, liver/kidney function tests, complete blood count) may be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.If you are taking allopurinol to treat kidney stones, you may benefit from a special diet. Consult your doctor for more details.

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. Need help identifying pills and medications? Use the pill identifier tool on RxList.