Reduction of cis-dichlorodiammineplatinum(II) caused nephrotoxicity by indazolone carboxylic acid.

To reduce the nephrotoxicity of cis-dichlorodiammineplatinum (cis-DDP) we have used tetrahydroindazolonedicarboxylic acid (HIDA) in doses of 200, 100 or 50 mg/kg 4, 2 and 1 h before or 1, 2 and 4 h after cis-DDP treatment (10 mg/kg). At any dose, given 2 or 1 h before or 1 h after cis-DDP, HIDA reduced the kidney damage as judged by the blood urea nitrogen (BUN) levels in blood. No protective effect was seen when HIDA was given 4 h before cis-DDP injection. Studies in vitro on L1210 cells have revealed that HIDA does not directly interact with cis-DDP.