Meropenem-induced pancytopenia in a preterm neonate: a case report.

Background: A post-marketing surveillance study has reported an association between meropenem use and the incidence of hematologic abnormalities, including leukopenia, thrombocytopenia, hemolysis, and neutropenia, but the precise incidence in neonates is unknown. Here, we report meropenem-induced pancytopenia in a preterm neonate.
Case Presentation: A preterm newborn Pakistani received intravenous meropenem 40 mg/kg every 8 hours to treat Klebsiella pneumoniae in blood cultures and suspected meningitis. The baby developed severe thrombocytopenia, with a platelet count of 22 × 10 3  cells/mm 3 , low hemoglobin level of 9.7 g/dl, and low absolute neutrophil count (ANC) of 816 cells/mm 3 on days 3, 14, and 17 of meropenem therapy, respectively. Based on the blood culture and institutional guidelines, meropenem treatment was continued with monitoring and supportive care for a total of 19 days. After discontinuation of meropenem, the baby was monitored continuously for hematological changes, and low counts persisted for 3 days. ANC improved to > 1500 cells/mm 3 on the fourth day, and the platelet count reached > 150 × 10 3  cells/mm 3 for the first time on the seventh day of meropenem discontinuation. All subsequent complete blood count (CBC) reports showed improving trends. The baby was discharged on the 48th day of life (DOL), with follow-up monitoring of CBC. The baby was kept on iron supplements, and hemoglobin level of 11.2 g/dl was observed on the 59th DOL.
Conclusion: Neonatal pancytopenia may lead to serious health complications; therefore, clinicians and pharmacists need to vigilantly monitor CBC in this vulnerable population, even when administering meropenem in septic doses for the recommended duration.