The Characteristics of Eosinophilia in a Series of Intravenous Methylphenidate Abusers

Seven cases of intravenous methylphenidate abuse are reviewed. A dramatic increase in absolute eosinophil count is noted, which decreases after discontinuation of the drug. Frequent associated complaints are pulmonary symptoms and fevers. The etiology of the eosinophilia is unknown. Mechanisms may include a hypersensitivity reaction to methylphenidate or an allergic reaction to the tablet fillers or diluents. The eosinophilia appears to resolve without complications.