•MOA: a weak organic acid that promotes renal clearance of uric acid by INHIBITING THE URATE-ANION EXCHANGER in the proximal tubule that mediates urate reabsorption • Blocks tubular secretion of: • Penicillin (used to increase levels of beta-lactam antibiotics) • Methotrexate • Naproxen • Ketoprofen • Indomethacin