Imipenem/cilastatin: a pharmacoeconomic appraisal of its use in intra-abdominal infections.

Imipenem/cilastatin possesses a very broad spectrum of antibacterial activity that encompasses the range of Gram-negative and Gram-positive aerobes and anaerobes usually associated with intra-abdominal and other polymicrobial infections. Its therapeutic efficacy is comparable to that of aminoglycoside/antianaerobe combination regimens, and the most commonly reported adverse effects are similar to those of other beta-lactam antibacterials and are generally of a non-serious nature. The acquisition cost of imipenem/cilastatin is generally greater than that of aminoglycoside/antianaerobe combination regimens, but treatment with the latter incurs the additional costs of multiple intravenous administration, aminoglycoside pharmacokinetic and other monitoring, and possible nephrotoxicity and ototoxicity. The available pharmacoeconomic studies show a trend towards lower total treatment costs with imipenem/cilastatin compared with gentamicin plus clindamycin. Results from other sources suggest that imipenem/cilastatin may achieve further cost savings through reduced duration of hospitalisation. Although further study is required to confirm these trends, it appears that the total treatment cost of imipenem/cilastatin does not exceed that of usual combination therapy and the risk of aminoglycoside-induced toxicity is avoided.