Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding. It also lowers the serum uric acid level by increasing urinary excretion of uric acid. Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding. It also lowers the serum uric acid level by increasing urinary excretion of uric acid. read more