Allopurinol (Zyloprim) reduces the amount of uric acid the body makes. Too much uric acid in the blood can cause damage and produce kidney stones and gout. Allopurinol will help to prevent gout, but will not ease an acute attack. It is also used to help prevent to decrease uric acid levels that occur as a result of some sorts of chemotherapy for certain types of leukemia, lymphoma or solid tumors.