[Clinical studies of intravenous drip infusion of micronomicin. 1. Pharmacokinetics (Part 2). Intravenous Micronomicin Research Group].

Following the previous report on pharmacokinetics of micronomicin (MCR) in healthy volunteers, pharmacokinetic studies were made again in patients with different degree of renal impairment, and a nomogram was obtained. MCR at a dose of 60 mg/time was given by 1-hour drip infusion to 14 inpatients who consented to receive MCR (age: 35 to 84 years, Ccr: 17.96 to 104.35 ml/min). The blood collection was performed in accordance with the schedule made upon the degree of renal impairment, and the serum concentration was determined by HPLC method. The results were analyzed by MULT program using two- or one-compartment open model. The serum concentration (Cmax) just after administration of MCR was 5.8 +/- 0.9 microgram/ml (mean +/- S.D.). The biological half-life was 1.81 to 12.35 hours. Taking the above results into consideration together with the previous ones of healthy males, the following correlation was obtained between the elimination constant (Kel or beta) and Ccr calculated from S-Cr.: Kel or beta = 0.0038 X Ccr - 0.0097. Further, no side effect was observed in these studies. Elimination of MCR from blood was dependent on renal function like other aminoglycosides, and so it was possible to estimate the elimination constant from Ccr. From these results, a nomogram for the optimum dosage regimen of MCR was obtained.