Pharmacokinetics and prophylactic efficacy of imipenem in abdominal surgery

Abstract

In a multicenter study of prophylaxis and pharmacokinetics, two different doses (500 mg and 1 gm) of imipenem/cilastatin administered by the intramuscular route were given to 212 patients undergoing elective abdominal surgery. The first dose was given 1 hour before the induction of anesthesia, and a dose was given every 6 hours for the following 48 hours to patients undergoing colorectal surgery and for the following 24 hours to those undergoing other abdominal operations. Bacteriologic cultures at the surgical site were obtained in 82% of patients; positive findings occurred in six (3.4%) patients, and postoperative infections occurred in two of these six patients. Infectious complications developed in 13 patients, and no significant differences in infection rate were observed between the two prophylactic regimens. Imipenem reached peak serum concentrations 2 hours after intramuscular administration. The concentrations in colonic mucosa and epiploic fat evaluated 1 to 1.5 hours after the dose was given exceeded minimal inhibitory concentration values for all common aerobic and anaerobic bacteria involved in postoperative infections. Based on our results, imipenem/cilastatin given intramuscularly should be considered for the antimicrobial prophylaxis of infections in abdominal surgery.