Cefotaxime kinetics after multiple-dose intramuscular study in healthy volunteers

The pharmacokinetics of cefotaxime after repeated doses of intramuscular injections were studied in 8 healthy volunteers receiving 1 g cefotaxime every 8 h for 6 days. Mean peak serum level after the first 1 g intramuscular dose was 26.8 +/- 6.4 micrograms/ml and the peak serum concentration was reached within 75 min. The half-life of cefotaxime was 1.35 +/- 0.33 h and the total apparent clearance 263 +/- 63 ml/min. After the last injection (day 6), the mean peak serum level reached 19.1 +/- 3.2 micrograms/ml and the areas under the curve were significantly lower than on day 1. No body accumulation of the drug could be detected. Serum levels of cefotaxime monitored throughout the study 5 min prior to and 30 min after the intramuscular injection were found above the minimum inhibitory concentration for most aerobic gram-positive and gram-negative sensitive organisms.