Imipenem/cilastatin versus aminoglycoside plus amoxicillin plus clindamycin in the treatment of serious postoperative infections.

In a prospective, controlled and randomized study, the clinical and bacteriological efficacy of imipenem/cilastatin was compared to that of a standard combination of an aminoglycoside (tobramycin or netilmicin), amoxicillin and clindamycin in patients with life-threatening postoperative infections. Doses used were imipenem/cilastatin 1 g q 8 h, amoxicillin 2 g q 8 h and clindamycin 0.6 g q 6 h. Aminoglycoside doses were individual and monitored six times weekly with serum concentration assays. Thirty-eight patients were entered into the study; 19 in each group. Diagnoses were pneumonia (five in the imipenem/cilastatin group and four in the combination group), peritonitis (eight in the imipenem/cilastatin and 13 in the combination group) and septicemia (five in the imipenem/cilastatin and two in the combination group). The two groups were comparable with respect to sex, age, underlying diseases and duration of antibiotic therapy. In the imipenem/cilastatin group, 14 patients were cured and one improved (79%). In the combination group, 11 were cured and 5 improved (74%). Four patients in the imipenem/cilastatin and five in the combination group failed to respond to treatment. In the former group 77% of the bacterial isolates were eradicated and 15% were suppressed. Corresponding frequencies in the combination group were 67% and 22%, respectively. Persistence of isolated pathogens was seen in 8% and 11%, respectively. It is concluded that imipenem/cilastatin seems to be an effective and well tolerated alternative to antibiotic combinations in the treatment of life-threatening postoperative infections. It also offers the advantages of fever antibiotic doses and renunciation of aminoglycoside serum concentration monitoring.