Probenecid increases the excretion of uric acid excretion in the urine. The drug was originally developed to competitively inhibit the renal excretion of some drugs, thusly increasing the plasma concentration and so prolonging the effects of the drugs.
Probenecid works by interfering with the kidney’s organic anion transporter, which itself re claims uric acid from the urine and returns it to the plasma. The organic anion transporter binds to probenecid instead of the uric acid (if probenecid is present) and prevents the reabsorption of the uric acid, causing the urine to retain more uric acid.
Primarily used in treatment of gout and hyperuricemia.