No Uric Allopurinol 100mg is a prescription medication primarily used to lower high levels of uric acid in the body. Elevated uric acid levels can cause conditions such as gout (a type of arthritis) and kidney stones. Allopurinol works by inhibiting the enzyme xanthine oxidase, which is involved in the production of uric acid. Allopurinol blocks the enzyme xanthine oxidase, which is responsible for converting purines (from certain foods or from cell breakdown) into uric acid. By reducing uric acid production, it helps to maintain a normal balance and reduce the risk of gout and kidney stones.