Meropenem-Induced Neutropenia in a Neonate

Postmarketing surveillance has associated meropenem with the development of hematologic abnormalities, including agranulocytosis, neutropenia, and leukopenia, but the exact incidence in children is unknown. The case describes a full-term, 26-day-old neonate admitted for a sepsis workup. She was found to have a blood culture positive for Enterobacter cloacae and suspected meningitis and was initiated on meropenem 40 mg/kg/dose intravenously every 8 hours. On day 14 of antibiotic treatment, the patient developed an isolated neutropenia with an absolute neutrophil count of 288 cells/mm³. Meropenem was discontinued on hospital day 20, and a follow-up complete blood cell count 2 months later confirmed resolution of the hematologic abnormality. Clinicians should monitor complete blood cell counts diligently in children who receive large doses and prolonged courses of meropenem.