Mechanisms of renal excretion of cisdichlorodiamine platinum

Eighteen diuretic rabbits were given cisdichlorodiamine platinum (CDDP) and the clearance of plasma water platinum was determined with a simultaneous inulin clearance. The rabbits were then given probenecid (50 mg/kg) or choline (50 mg/kg) and the clearance of free platinum was calculated. CDDP has a high clearance, exceeding glomerular filtration rate. The drug appears to be secreted by the anionic transport system in the proximal tubule, as the clearance of free platinum is markedly decreased by the administration of probenecid.