[A case of eosinophilic pneumonia possibly due to ifenprodil]

A 69-year-old woman with a history of subarachnoid hemorrhage was started on ifenprodil for dizziness. Three weeks later, fever, cough, chills, dyspnea and skin eruption developed. A chest radiograph showed bilateral ground-glass shadows. Blood tests showed a white cell count of 14,400/mm3 with 32% eosinophils and a C reactive protein (CRP) level of 20 mg/dl. The arterial blood gases on room air were as follows: pH 7.45, PaCO2 33 torr, and PaO2 56 torr (Table 1). Ifenprodil was withdrawn and intravenous meropenem and minocycline administration was started on admission. Her fever improved rapidly and the CRP decreased, but hypoxemia and hypereosinophilia persisted. On the third hospital day, she underwent bronchoscopy with bronchoalveolar lavage (BAL). The differential count of BAL cells was 63% eosinophils, 15% lymphocytes, 21% macrophages, and 1% neutrophils. Intravenous methylprednisolone 250 mg/day for 3 days was commenced, leading to a clinical improvement. She received oral prednisolone (30 mg/day) for the next 4 days, and was then discharged without any symptoms. She has had no recurrence since. Both the drug lymphocyte stimulation test and the skin test for ifenprodil were negative.