Pharmacokinetics of single intravenous and intramuscular doses of cefotetan in normal human volunteers.

The pharmacokinetic parameters of cefotetan were determined in six healthy adults after intramuscular (im) and intravenous (iv) administration of a single dose. After an iv bolus injection of 1 g cefotetan the mean peak serum level was 179.6 mg/l (S.E.M. +/- 14.2 mg/l) at 2 min. The apparent volume of distribution was 10.29 l (S.E.M. +/- 0.66 l). After im injections of 500 mg and 1 g of cefotetan the mean peak levels were 35 mg/l (S.E.M. +/- 1.6 mg/l) and 74 mg/l (S.E.M. +/- 3.6 mg/l) at 82 and 97 min respectively; the level at 12 h was 4.5 mg/l after 500 mg and 10.4 mg/l after 1 g. Cefotetan was slowly eliminated. The serum half-life was about 3.1 h after 1 g iv injection and varied from 3.4 to 3.7 h after the 500 mg and 1 g im injections. About 75% of the dose was excreted in the urine during the first 24 h after 1 g iv bolus injection; after 500 mg and 1 g im injection 60 to 65% of the dose was recovered in the urine during the same time period.