Eosinophilia associated with bupropion

To describe the first incidence of eosinophilia following administration of bupropion.

The patient was a 72-year-old woman admitted for evaluation of chest pain. During hospitalization, the eosinophil count reached 0.60 fraction of 1.00, with absolute eosinophil count of 6693 x 10(6)/L and a white blood cell count of 18.5 x 10(9)/L. She had been receiving bupropion therapy for 5 days prior to this admission.

Potential causes of the eosinophilia, including disease states and medications, were reviewed comprehensively and ruled out. A review of the literature (MEDLINE 1966-1994) did not identify previous cases of eosinophilia associated with bupropion therapy. Causes of eosinophilia include parasitic infections, allergic diseases, and medication use. A proposed mechanism for the occurrence of eosinophilia in this patient is unknown.

Considering the temporal sequence of events, drugs administered prior to the development of eosinophilia, and the rapid decline of the eosinophil count following discontinuation of the medication, bupropion appears to be the precipitating agent.