Assessment of an alternative meropenem dosing strategy compared with imipenem-cilastatin or traditional meropenem dosing after cefepime failure or intolerance in adults with neutropenic fever.

STUDY
OBJECTIVE: To compare clinical outcomes of patients receiving an alternative dosage of meropenem with those of patients receiving imipenem-cilastatin or the traditional dosage of meropenem after failure of or intolerance to cefepime for treatment of febrile neutropenia.
DESIGN: Retrospective, single-center cohort study.
SETTING: 1250-bed urban academic medical center. PATIENTS: One hundred twenty-seven adults with neutropenic fever who received either imipenem-cilastatin or meropenem; imipenem-cilastatin was the preferred carbapenem until September 1, 2006, after which meropenem became the formulary carbapenem.
MEASUREMENTS AND MAIN RESULTS: Of the 127 patients, 40 received imipenem-cilastatin 500 mg every 6 hours between September 1, 2005, and August 31, 2006; 87 patients received meropenem between September 1, 2006, and August 31, 2007: 29 received a traditional dosage of meropenem 1 g every 8 hours, and 58 received an alternative dosage of meropenem 500 mg every 6 hours. Primary outcomes of time to defervescence (median 3 vs 2 vs 3 days), need for additional antibiotics (20% vs 17% vs 14%), and time to receipt of additional antibiotics (median 5 vs 2 vs 1 days) were not significantly different among the imipenem-cilastatin, traditionally dosed meropenem, and alternatively dosed meropenem groups, respectively. In addition, significant differences in secondary outcomes, which were treatment duration (median 10 vs 8 vs 8 days), seizure rate (0% vs 0% vs 0%), in-hospital mortality (5% vs 7% vs 7%), and 30-day mortality (13% vs 7% vs 14%), were not identified among the three groups, respectively.
CONCLUSION: The alternative meropenem dosage of 500 mg every 6 hours yielded similar patient outcomes, including time to defervescence, need for additional antibiotics, duration of therapy, and mortality, when compared with the traditional meropenem dosage and imipenem-cilastatin in adults with febrile neutropenia. In addition, no adverse effects on clinical outcomes were observed with the alternative dosage of meropenem.