Relationship between development of nephrotoxicity and blood concentration of cyclosporine A in bone-marrow transplanted recipients who received the continuous intravenous infusion.

This study was undertaken to investigate the relationship between blood concentration of cyclosporine A (CsA), administered intravenously by a 24-h continuous infusion, and drug-induced nephrotoxicity or hepatotoxicity. It was investigated retrospectively in 8 patients who had received an allogeneic bone marrow transplant (BMT). The correlation between daily doses and blood concentration of CsA was not significant. Then, the data of blood concentration of CsA and renal or liver function test result were divided into 5-d periods from the date of transplantation, and the mean value for each period was calculated. The maximum values of blood urea nitrogen (BUN) and serum creatinine (SCr) were consistently observed only after the period when the 5-d mean CsA concentration reached the peak level: the maximum BUN and SCr values were witnessed at Periods 2 to 10 and at Periods 1 to 9, respectively. On the other hand, no consistent correlation was found between the 5-d mean CsA concentrations and liver function test result. We also investigated the relationship between renal function and the cumulative dose or AUC of CsA. The parameters of renal function tests reached peak levels at the cumulative dose of 4000 to 10000 mg and at the cumulative AUC of 280000 to 660000 ng/ml.h. These results suggest that: 1) a deterioration of renal function occurs usually after the peak blood concentration of CsA is attained, and 2) the monitoring of the blood concentration of CsA is useful in predicting renal dysfunction in post-BMT patients.