A COMPARISON OF AZTREONAM PLUS VANCOMYCIN AND IMIPENEM PLUS VANCOMYCIN AS INITIAL THERAPY FOR FEBRILE NEUTROPENIC CANCER-PATIENTS

BACKGROUND. The improved efficacy of imipenem over other beta-lactam a ntibiotics in the treatment of febrile neutropenic patients has been a ttributed to its broad spectrum of activity. METHODS. A prospective, r andomized, clinical trial was performed comparing vancomycin 1 g every 12 hours plus imipenem/cilastatin 500 mg every 6 hours and the same d ose of vancomycin plus aztreonam 2 g every 6 hours for empiric treatme nt of febrile episodes in neutropenic patients with cancer. RESULTS. T he imipenem regimen cured 76% of the 148 evaluable episodes compared w ith a 67% cure rate for the 152 episodes treated with the aztreonam re gimen (P = 0.1). Most of the polymicrobial infections (77% or 10/13) t reated with the imipenem responded, whereas only 38% (5/13) of these i nfections responded to the aztreonam regimen. Although the cost of the imipenem regimen was less than the cost of the aztreonam regimen, it was associated significantly more with skin rashes (12/194 vs. 3/189, P = 0.02). In a multivariate analysis, a poor outcome was independentl y associated in both instances with the persistence of neutropenia and the presence of pneumonia (P < 0.001). CONCLUSIONS. Overall, in a mul tifactorial analysis that included efficacy, toxicity, and cost, the i mipenem and aztreonam regimens were comparable. (C) 1996 American Canc er Sociery.