Clinical pharmacology of netilmicin

Pharmacological studies of netilmicin were conducted in 30 cancer patients. After intravenous administration of 50 mg of netilmicin or gentamicin per m(2) over a 1-h period in 10 patients, the mean peak serum concentrations occurred at the end of the infusion and were 7.6 and 7.3 mug/ml, respectively. At 6 h, the mean serum concentrations of both drugs was 1.1 mug/ml. After intramuscular injection of 50 mg of netilmicin per m(2) to each of the same 10 patients, the mean peak serum concentration was 5.5 mug/ml and occurred at 1 h, and, at 6 h, the mean serum concentration was 1.4 mug/ml. The mean proportion of netilmicin excreted in urine during 6 h after intramuscular injection was 55%, and after intravenous injection it was 40.9%. Results were similar with gentamicin sulfate. After administering 60 mg of netilmicin per m(2) intravenously over 30 min every 6 h in 9 patients, the mean peak serum concentration (7.9 mug/ml) occurred at the end of the infusion. The concentration gradually decreased to below 2.0 mug/ml after 4 h. Continuous infusion of 60 mg of netilmicin per m(2) every 6 h after a 60-mg/m(2) loading dose in 11 patients produced levels consistently above 2.9 mug/ml, during the initial 6-h infusion, and levels above 2.0 mug/ml for at least 1 week.