[Contribution of imipenem/cilastatin in the treatment of peritonitis: a comparative economic analysis in the case of France].

Imipeneme, a molecule chemically related to the carbapenems (beta-lactam), is a potent wide spectrum antibiotic reserved for hospital use. Effective as therapy for major infections, and for use in severely debilitated patients (immunodepressed, etc ...) its efficacy in the treatment of peritonitis has been demonstrated in numerous studies abroad, confirmed by results of a French multicenter trial in 1989. Its cost-effectiveness ratio was assessed as excellent in a comparative case-controlled study of totally matched patients treated with other antibiotics. As expected, the cost of the treatment itself (imipeneme/cilastatine plus associated products and costs of their administration) was higher by about 1000 F per patient when compared with other antibiotic regimens, but its markedly superior efficacy allowed overall economies of about four and a half times this sum (4300 F). This cost reduction was related to different factors, some of which could not be individualized because of missing data (personnel) or protocol bias (laboratory examinations). Nevertheless, the global result was a shortening of hospital stay by more than two days due to a very pronounced decrease in failure rate of the first treatment. This result is even more remarkable in that the peritonitis treated by Tienam was significantly more severe than that treated by the other antibiotics.