An alternative meropenem dosing strategy (500mg q6h) has been postulated to provide similar pharmacodynamics based on %T>MIC as traditional dosing with 1gm q8h while decreasing total daily dose. However, this dosing strategy has not been formally evaluated for empiric treatment of febrile neutropenic patients. The aim of this study was to compare clinical outcomes in patients treated with alternatively-dosed meropenem at 500mg q6h (Mero500q6), traditionally-dosed meropenem at 1gm q8h (Mero1q8), and imipenem-cilastatin at 500mg q6h (Imi500q6) following failure or intolerance of cefepime for febrile neutropenia.
A retrospective, single-center, observational cohort study was performed.
Barnes-Jewish Hospital, a 1,250 bed urban academic medical center in St. Louis, MO.
Adult neutropenic fever patients admitted to either the Hematologic Malignancy or Hematopoietic Stem Cell Transplant service.
A total of 127 patients were included: 40 patients treated with Imi500q6 from September 1, 2005, to August 31, 2006, and 87 patients treated with meropenem (Mero1q8=29, Mero500q6=58) from September 1, 2006, to August 31, 2007.
Measurements and main results
Primary outcomes including time to defervescence (median 3 vs. 2 vs. 3 days), need for additional antibiotics (20% vs. 17.2% vs. 13.8%), and time to additional antibiotics (median 5 vs. 2 vs. 1 days) were not statistically different between the Imi500q6, Mero1q8 and Mero500q6 groups, respectively. Differences in secondary outcomes including treatment duration (median 10 vs. 8 vs. 8 days), seizure incidence (0% vs. 0% vs. 0%), in-hospital mortality (5% vs. 6% vs. 7%), and 30-day mortality (12.5% vs. 6% vs. 14%) were not identified.
Mero500q6h yielded similar patient outcomes, including time to defervescence, need for additional antibiotics, duration of therapy, and mortality as compared to traditional dosing of meropenem and imipenem-cilastatin in adult patients with febrile neutropenia and had no observed adverse impact on clinical outcomes.