Meta-analysis of the clinical outcome of carbapenem monotherapy in the adjunctive treatment of intra-abdominal infections

v Background The carbapenems, a class of β-lactam antimicrobials with efficacy against both aerobic and anaerobic organisms, have demonstrated potential as monotherapeutic regimens in the treatment of serious intra-abdominal infections. Clinical trials have been conducted in the past decade to compare carbapenem monotherapy versus combinations of antibiotic therapy. We report here a meta-analysis of 10 such trials. Data sources An 11-year Medline search (from 1985 through 1996) of the English-language literature identified clinical trials that compared the outcomes of carbapenem monotherapy, either imipenem/cilastatin or meropenem, versus another antibiotic regimen in intra-abdominal infections in human subjects. Ten randomized, prospective trials were found, with a total of 1,227 clinically evaluable patients. A meta-analysis of these clinical trials was performed to determine the difference in clinical outcomes between carbapenem monotherapy versus other antibiotic regimens. We found a difference in response rates of −1.6% (95% confidence interval [CIJ −5.7% to 2.5%) and a response ratio of 0.99 (95% CI, 0.90 to 1.09), indicating no statistical significant difference. Conclusions A meta-analysis of 10 clinical trials from 1985 through 1996 has revealed no statistical significant difference in clinical response between carbapenem monotherapy and combinations of antibiotic therapy in intra-abdominal infections. We noted, however, that the earlier studies reported more favorable response ratios for carbapenems than later publications. This may have been due to the selection of less effective comparators in earlier studies. We conclude that carbapenem monotherapy is as effective as combinations of antimicrobials for the treatment of intra-abdominal infections.