Intramuscular imipenem/cilastatin in the treatment of mild and moderate infections.

Imipenem/cilastatin is the combination of a broad spectrum beta-lactam antibiotic with dehydropeptidase I--an inhibitor of the metabolism of imipenem. Clinical trials have shown that imipenem/cilastatin given intravenously is effective in the treatment of mild, moderate or severe infections. A new milled form of imipenem has been developed for intramuscular use as a suspension with cilastatin, which provides a longer effective half-life of three to four hours with lower peak concentrations of imipenem. A multicenter clinical trial was instituted in the treatment of mild and moderate infections with 500 mg b.i.d. and 500 mg t.i.d. or 750 mg b.i.d., respectively. All 500 mg doses were suspended in saline while the 750 mg doses were in 1% lidocaine. A total of 346 (126 on 500 mg b.i.d., 70 on 500 mg t.i.d. and 128 on 750 mg b.i.d.) were entered. Another 22 patients received a combination of the two regimens. Of the total 346 patients entered, 286 were considered evaluable for efficacy. Skin and soft tissue infections were the most common followed by intra-abdominal, respiratory and urinary tract infections. Overall favorable outcomes were demonstrated in 98.7% with a range of 92 to 100%. All patients were included in the safety analysis. Clinical adverse experiences (AEs) were reported in 3.2% of patients with two AEs considered drug related. Both were pain at the injection site with 500 mg doses. No injection site pain was reported as AEs with the 750 mg doses. Laboratory AEs were reported in 17% and considered drug related in 7% (primarily liver enzymes changes).(ABSTRACT TRUNCATED AT 250 WORDS)