Randomized trial comparing netilmicin plus imipenem-cilastatin versus netilmicin plus ceftazidime as empiric therapy for febrile neutropenic bone marrow transplant recipients

Empirical antimicrobial treatment for chemotherapy-induced febrile neutropenia

Febrile neutropenia in immunocompromised hosts is associated with a high mortality. Empirical treatment in such cases is instituted to cover the common pathogens. Generally, combination antibiotic treatment is used early in the febrile neutropenia phase. Recent studies demonstrate that monotherapy with certain beta-lactam antibiotics can be equally effective. Glycopeptide antibiotics are used in the absence of an adequate response to the initial antibiotics. Empirical antifungal therapy may be given if fever does not settle in 72-96 h despite antibiotics. Newer antifungal agents have increased the available options for initial antifungal agents though more data are needed before any conclusive recommendation can be made. Recent changes in the epidemiology of multiresistant organisms necessitate local microbiological input into empiric policies with increasing need to consider cover for methicillin-resistant Staphylococcus aureus, glycopeptide intermediate S. aureus, vancomycin-resistant S. aureus, vancomycin-resistant enterococci, Gram-negative bacilli that produce extended-spectrum beta-lactamases, Stenotrophomonas maltophilia, and multi-resistant Acinetobacter baumanii.

An open, randomized, multicentre study comparing the use of low-dose ceftazidime or cefotaxime, both in combination with netilmicin, in febrile neutropenic patients. German Multicentre Study Group

To reduce drug acquisition costs, the clinical and bacteriological efficacy of low-dose ceftazidime i.v. (1 g tid) was compared with cefotaxime i.v. (2 g tid). Both regimens were combined with netilmicin i.v. (2 mg/kg bodyweight tid), in an open, randomized, multicentre trial in febrile neutropenic patients. The addition of antibiotics for gram-positive coverage was part of the protocol; alteration in the antibiotics for gram-negative cover or premature discontinuation of the study antibiotics were judged as failure. One hundred and eighty six patients were randomized by nine German centres, the patients matched for age, underlying diseases and duration of neutropenia (median duration 14 days) in both treatment arms. Infections were documented microbiologically in 29% of the patients, clinically in 16% and suspected (fever of unknown origin) in 102/186 patients (55%). The 82 pathogens isolated were predominantly gram-positive bacteria. In an intent-to-treat analysis, the overall response rate without modification at the final evaluation was 58% in the ceftazidime group and 34% in the cefotaxime group (P < 0.01). The success rates with modification were 84% and 64%, respectively. The failure rate in a highly immunosuppressed subgroup of the patients (bone marrow transplant recipients) was higher for cefotaxime (53%) than for the ceftazidime arm (14%) (P < 0.001). Response rates were significantly higher in the ceftazidime group for patients with microbiologically documented and possible infections. No major bacterial superinfections occurred in the low-dose treatment arm. The tolerability was good for both regimens. Low-dose ceftazidime combined with netilmicin proved to be superior to recommended doses of cefotaxime/netilmicin in febrile neutropenic patients.