Imipenem/cilastatin therapy for serious bacterial infections

Imipenem was administered intravenously with cilastatin to patients with suspected or documented significant infections. The mean peak serum level of imipenem 30 min after infusion of a 500 mg dose was 18.4 micrograms/ml, and the mean trough level (30 min before infusion) was 2.4 micrograms/ml. The organisms isolated before therapy included Enterobacteriaceae, Staphylococcus aureus, streptococci, Pseudomonas aeruginosa, and anaerobes. The response rate in 25 assessable patients was 96%, with 40% experiencing a complete cure and 56% improvement. Therapy failed in only one instance because an isolate of P. aeruginosa was mistakenly reported to be susceptible on disk testing. Toxicity in the 33 patients treated was generally minimal and included phlebitis, mild liver function abnormalities, eosinophilia, and thrombocytosis. The emergence of resistant organisms during therapy was very uncommon. Imipenem/cilastatin is a promising agent for the treatment of complicated infections.