Allopurinol controls Uric acid. Normal uric acid is dissolved in blood, and it is filtered in the kidneys and expelled out of the body through urine. Uric acid would increase when there is excess production of the same or when your kidneys are unable to clear it. This disease is hyperuricemia. Uric acid can be painful especially when it is increased. Allopurinol is normally prescribed to prevent but not treat these disorders.