Population pharmacokinetics and renal toxicity of cisplatin in cancer patients with renal dysfunction.

PURPOSE: The pharmacokinetics (PKs) of cisplatin have not been investigated in patients with renal dysfunction, characterized by creatinine clearance (Ccr) < 60 mL/min. In this study, we performed a population pharmacokinetic (PPK) analysis of unchanged cisplatin in patients with renal dysfunction. We investigated the effects of renal dysfunction on the PKs and nephrotoxicity of unchanged cisplatin. METHODS: We enrolled 23 patients with moderate renal dysfunction (Ccr calculated to be 30-60 mL/min using the Cockcroft-Gault formula) treated with cisplatin. PPK analysis was performed by nonlinear mixed effect modeling using NONMEM (Version 7.2). We evaluated gender, age, body surface area (BSA), weight, baseline Ccr, baseline serum creatinine (Scr), and baseline urea nitrogen as potential covariates. The final model was evaluated using bootstrap analysis. Renal toxicity was evaluated using Common Terminology Criteria for Adverse Events ver. 4.0. The frequency of severe renal dysfunction (Grade 3/4 Scr elevation) was measured in the population. RESULTS: A one-compartment model adequately described the unchanged cisplatin data. The population mean values for clearance (CLtot) and volume of distribution (Vd) were 19.1 L/h [coefficient of variation (CV) 19.4%] and 13.8 L (CV 41.0%), respectively. The final model identified BSA as a significant covariate for CLtot. There were no significant covariates for Vd. No patients suffered from severe nephrotoxicity to the point that hemodialysis was required. CONCLUSION: Moderate renal dysfunction does not affect the PKs of unchanged cisplatin. The increased serum concentration of cisplatin may not lead to increased toxicity in patients with renal dysfunction. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: UMIN000007091 (January 17, 2012).