uricosuric

Uricosuric describes substances or effects that increase the excretion of uric acid in the urine. In pharmacology, uricosuric agents are used to treat hyperuricemia and gout by enhancing renal clearance of urate, thereby lowering serum urate levels.

Most uricosurics work by inhibiting proximal tubule reabsorption of urate, often through blockade of urate transporters such as URAT1. This raises urate excretion and reduces uric acid buildup. The approach is typically used for patients who primarily underexcrete uric acid rather than produce excess amounts.

Common historical uricosuric drugs include probenecid and sulfinpyrazone. Benzbromarone was used in some regions but has largely been withdrawn due to hepatotoxicity. Newer agents that inhibit urate reabsorption, including URAT1 inhibitors, have been developed to provide alternatives or adjuncts to xanthine oxidase inhibitors.

Indications for uricosurics include management of chronic gout in patients with renal function capable of supporting urate excretion and in whom uric acid production is not excessive. They are sometimes used in combination with urate-lowering therapies such as xanthine oxidase inhibitors to achieve stronger urate control. They are not suitable for all patients, particularly those with significant renal impairment or a history of uric acid stones.

Adverse effects may include hypersensitivity, gastrointestinal upset, and an increased risk of renal stone formation due to higher urinary uric acid. Drug interactions can occur with medications excreted renally, such as certain antibiotics or methotrexate, and with NSAIDs or aspirin.

See also: gout, uric acid, URAT1, xanthine oxidase inhibitors.