ZYLOPRIMZyloprim (Allopurinol) is used to treat chronic gout (gouty arthritis). This condition is caused by too much uric acid in the blood. This medicine works by causing less uric acid to be produced by the body. Allopurinol will not relieve a gout attack that has already started. Also, it does not cure gout, but it will help prevent gout attacks. However, it works only after you have been taking it regularly for a few months. Allopurinol will help prevent gout attacks only as long as you continue to take it. Allopurinol is also used to prevent or treat other medical problems that may occur if too much uric acid is present in the body. These include certain kinds of kidney stones or other kidney problems.