Nephrotoxicity of cis-diamminedichloroplatinum with or without ifosfamide in cancer treatment.

cis-Diamminedichloroplatinum (DDP) and ifosfamide (IPP) are effective cytostatic agents with a considerable nephrotoxicity. Because of the known synergism of both drugs in animals the combination has been studied in man with disseminated testicular cancer. Nature and extent of nephrotoxicity of DDP in combination with vinblastine, bleomycin and with or without IPP was investigated. The renal involvement was studied during volume expansion and mannitol diuresis. In addition to total kidney function (creatinine clearance and renal electrolyte handling), tubular function has been determined by quantitative assessment of urinary albumin, beta 2-microglobulin, maltase and leucine aminopeptidase excretion. The urinary protein pattern was also analyzed by microgradient electrophoresis to determine low and high molecular weight proteins. The total protein excretion was raised in the groups of patients with DDP and IPP to a 5-fold of the normal (976 +/- 96 mg/24 h) versus a 4-fold increase (756 +/- 102 mg/24 h) without IPP. This was mainly due to renal tubular involvement. For example, IPP raised the tubular toxicity induced by DDP considerably with a 200-fold increase of the beta 2-microglobulin excretion versus only a 10-fold increase without IPP (p less than 0.02). All lesions were reversible and caused no lasting impairment of kidney function. It is concluded that combination regimens including DDP and IPP can be used without a major risk of acute or chronic renal insufficiency. However, urinary protein excretion should be monitored to make certain that the tubular function improves between or after the treatment courses.