Allopurinol is used for the prevention of urate urinary stones by reducing the production of uric acid in your body. Allopurinol comes as a tablet to take by mouth. It is usually taken once or twice a day, preferably after a meal. To help you remember to take allopurinol, take it around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take allopurinol exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
The common side effects of this medicine are diarrhea, cramping or nausea. Another side effect is skin rashes, which occurs only when used with Ampicillin and Amoxicillin
By various manufacturers.