[Study on the serum concentrations of gentamicin after intravenous drip infusion].

Serum concentrations of gentamicin (GM) were monitored after intravenous drip infusion of 60 mg over 30 minutes, 1 hour and 2 hours. These concentrations were compared with those after intramuscular injection. The mean peak serum concentration obtained at 30 minutes after intramuscular injection (5.09 micrograms/ml) and those obtained at the end of intravenous drip infusion (5.17--6.66 micrograms/ml) were comparable. Serum concentrations decreased to less than 2.0 micrograms/ml at 6 to 8 hours after injection or infusion in all cases except 1 with less body weight than others. Pharmacokinetic analysis showed that the T1/2 of GM ranged from 2.49 to 4.33 hours and that the AUC ranged from 19.66 to 27.09 hr X micrograms/ml. Results obtained in this study suggested that the usefulness of intravenous drip infusion over the time from 30 minutes to 2 hours is equal to that of intramuscular injection in the GM therapy.