A retrospective evaluation of imipenem use in bone marrow transplant patients

A retrospective, open, 3-year trend analysis of imipenem use in bone marrow transplant (BMT) patients was conducted at a 1000-bed tertiary care hospital. Broad-spectrum antibacterial drugs are routinely used to treat infections in the febrile neutropenic host. The antibacterial activity and acceptable tolerance profile of imipenem makes this agent a potentially useful addition to the traditional armamentarium which includes aminoglycosides, cephalosporins, and glycopeptides. Some authorities recommend imipenem as monotherapy in the treatment of fever of unknown origin in this select patient population. Eighty-three treatment courses (one treatment course per patient) were evaluated. The major indications for initiating therapy were fever of neutropenia (28%), suspected infection in the absence of fever (55%), and documented infection (17%). Imipenem was used as a first-line agent in 42% of patients, although imipenem monotherapy was not common. Concurrent antibacterials were usually vancomycin and tobramycin. Seventeen patients required modification of the initial regimen with vancomycin and/or tobramycin for additional coverage after an average of 8 days of imipenem therapy. Forty-eight bacterial isolates were obtained in cultures from 35 patients during the study, with gram-positive organisms predominating (in particular, staphylococci and streptococci). Pretherapy and superinfecting organisms were primarily gram-positive. Overall clinical success or improvement occurred in 42% of patients. Microbiologic outcome was indeterminate in 89% of patients, microbiologic eradication occurred in 1%, and superinfection occurred in 6%. Imipenem was relatively well tolerated. Rash and nausea/vomiting were reported most often; 29% of those patients who had adverse reactions discontinued therapy.