title: Drug-induced thrombocytopenia:  a less known interaction.
abstract: A 57-year-old woman with a left frontal lobe tumor was started on seizure prophylaxis with phenytoin and dexamethasone while awaiting elective surgery for tumor excision. Within a week, she developed a rash all over her body secondary to phenytoin hypersensitivity and her platelet counts decreased progressively to as low as 20,000/μl. Phenytoin was discontinued and she was given intravenous immunoglobulin for 2 days. She had progressive recovery of the platelet count to her baseline over the next 6 days. This case of phenytoin-induced thrombocytopenia emphasizes the importance of recognizing thrombocytopenia secondary to drug use and also highlights a lesser known but important interaction between phenytoin and dexamethasone to enhance this effect. We also provide a brief review of the literature and comment on the pathophysiology of this rare condition.
authors.affiliation: Johns Hopkins University/Sinai Hospital of Baltimore, Baltimore, Maryland 21215, USA. pandey.manjari@gmail.com
authors.forename: Manjari
authors.initials: M
authors.lastname: Pandey
authors.forename: Lavanya
authors.initials: L
authors.lastname: Yarlagadda
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects*; D003907:Dexamethasone / Q000009:adverse effects*; D004347:Drug Interactions; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008875:Middle Aged; D010672:Phenytoin / Q000009:adverse effects*; D010976:Platelet Count; D012640:Seizures / Q000188:drug therapy; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000188:drug therapy
chemical_list: D000927:Anticonvulsants; D005938:Glucocorticoids; D016756:Immunoglobulins, Intravenous; D010672:Phenytoin; D003907:Dexamethasone