The difference between allopurinol and benzbromarone is that the mechanism of lowering uric acid is different. Allopurinol belongs to the inhibition of uric acid synthesis of drugs, benzbromarone is to increase uric acid excretion of drugs, both through different ways to reduce blood uric acid. 1. Allopurinol: the mechanism of action of allopurinol is to inhibit the important oxidase enzyme in the process of uric acid generation, namely xanthine oxidase, to prevent the metabolism of xanthine and hypoxanthine into uric acid, inhibit the generation of uric acid, especially for excessive uric acid generation of hyperuricemia. Adverse reactions mainly include skin rash, gastrointestinal reactions. Contraindicated in drug allergy, severe hepatic and renal insufficiency, pregnant and lactating women. Note that the drug can only be used after the disappearance of gout inflammation, and the liver and kidney function and blood picture are checked regularly during the use of the drug. 2. Benzbromarone: mainly through the inhibition of renal tubular reabsorption of uric acid to reduce blood uric acid, applicable to primary hyperuricemia, gouty arthritis intermittent period. Adverse reactions include gastrointestinal discomfort, skin itching, etc., and liver injury in serious cases. It is contraindicated for those who are allergic to the components of the drug, and for pregnant women who are at risk of pregnancy and nursing mothers. Note that it can not be taken during an acute attack of gout, large amounts of water are needed during treatment, and when using the drug for a long time, pay attention to checking the liver and kidney functions. It is recommended that patients use the appropriate medication under the guidance of a doctor and avoid self-medication.