Allopurinol belongs to a group of medicines called enzyme inhibitors. These medicines inhibit the amount of uric acid production in your body. Allopurinol works by slowing down the speed of certain chemical reactions in your body to lower the level of uric acid in the blood and urine. Allopurinol Tablets are used to treat the following conditions: Gout(increased uric acid quantity in the body). The uric acid builds up in your joints and tendons as crystals causing an inflammatory reaction. The inflammation causes the skin around certain joints to become swollen tender and sore when only slightly touched. You may also get severe pain when the joint is moved. Kidney stones formation and certain other types of kidney diseases due to increase in the amount of uric acid in the body. Some types of Cancer due to increase in the amount of uric acid in the body. Enzyme disorders due to increase in the amount of uric acid in the body.