<prompt> Mechanism of action of allopurinol isXanthine oxidase inhibitionRecombinant uricaseIncrease uric acid excretionDecrease chemotaxis  <response>: Allopurinol hypoxanthine analog and recently approved drug, decrease the production of uric acid by inhibiting the enzyme xanthine oxidase. Dose- 100-600 mg day Allopurinol is metabolized by the same enzyme to allo xanthine which is a long acting inhibitor of xanthine oxidase. Allopurinol purine analogue and Febuxostat non-purine analogue are indicated as drug of choice for chronic gout in the inter-critical period between two acute attacks and also with anticancer drugs to decrease secondary hyperuricemia. DRUGS USED IN CHRONIC GOUT Group Mechanism Drugs Uric acid synthesis inhibitors Xanthine oxidase inhibitors Allopurinol, Febuxostat Uricosuric agents URAT-1 transpoer inhibitors Probenecid, Sulfinpyrazone, Benzbromarone, Lesinurad Recombinant uricase Cause oxidation of urate to allantoin Rasburicase, Pegloticase 