Eosinophilia Possibly Associated with Intravenous Levofloxacin

Abstract

Objective: To report the first published case of eosinophilia following the administration of intravenous levofloxacin. Case Summary: An 84-year-old white man was admitted for community-acquired pneumonia, for which he received intravenous levofloxacin therapy. The absolute eosinophil count on admission was 120 cells/mm3 (differential 3.5%). On day 6 of admission and therapy, the absolute eosinophil count peaked at 957 cells/mm3 (differential 16.8%) and then returned to a normal value of 1.2% on day 7, one day after discontinuation of levofloxacin. Discussion: Fluoroquinolones are broad-spectrum antimicrobials used frequently to treat a variety of infections. A review of MEDLINE (1996-May 1999) did not yield any previous reports of eosinophilia associated with intravenous levofloxacin therapy. However, many quinolones have been associated with eosinophilia, occasionally with significant associated morbidity. This patient's eosinophilia developed within one day of initiating levofloxacin and resolved within one day of discontinuation of the drug. To our knowledge, this is the first reported case of eosinophilia related to intravenous levofloxacin therapy. Conclusions: The temporal relationship of events in this case suggests that levofloxacin was the cause of this patient's eosinophilia. We report this case to alert clinicians to the possibility of eosinophilia associated with levofloxacin.