title: Cefotaxime kinetics after intravenous and intramuscular injection of single and multiple doses.
abstract: The kinetics of cefotaxime, a cephalosporin with an unusually broad antibacterial spectrum, were examined in humans after intravenous bolus injection, intravenous infusion every 6 hr for 14 days, and intramuscular injection every 8 hr for 10 days. Mean peak serum level after bolus injection of 500 mg was 37.9 microgram/ml; after 1 gm, 102.4 microgram/ml; and after 2 gm, 214.1 microgram/ml. The half-life (t1/2) was 1 hr for the 3 doses. Total serum clearance was the same for all doses. Overall excretion was 50% to 60%; part of the drug was excreted as the desacetyl derivative. After multiple intravenous infusion the elimination rate constants and t1/2 were the same on days 1 and 15. Assayable levels were present on all days 5 min before injection of a dose. Multiple intramuscular injections of 500 mg produced serum levels of 9.2 to 11.9 microgram/ml. The t1/2 was 0.93 hr. Mean serum levels at 8 hr ranged from 0.08 to 0.55 microgram/ml. Serum levels produced by intravenous infusion or intramuscular injection were inhibitory for most (90%) aerobic gram-positive and gram-negative organisms susceptible to cefotaxime.
mesh_terms: D000328:Adult; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002437:Cefazolin / Q000494:pharmacology; D002439:Cefotaxime; D002511:Cephalosporins / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D004361:Drug Tolerance; D006207:Half-Life; D006801:Humans; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male
chemical_list: D002511:Cephalosporins; D002437:Cefazolin; D002439:Cefotaxime