title: Thrombocytopenia associated with PF3 antiplatelet activity against the sulfa component of trimethoprim-sulfamethoxazole.
abstract: A 3-year-old white boy had symptomatic thrombocytopenia after receiving trimethoprim-sulfamethoxazole in recommended doses for one week. The platelet count returned to normal soon after the medication was discontinued. In vitro admixing of donor platelets with a sample of the patient's serum demonstrated antiplatelet activity with the sulfamethoxazole component, but not with the trimethoprim component of the drug.
mesh_terms: D001779:Blood Coagulation Factors / Q000276:immunology*; D002675:Child, Preschool; D006801:Humans; D008297:Male; D010977:Platelet Factor 3 / Q000276:immunology*; D013420:Sulfamethoxazole / Q000009:adverse effects*; D013921:Thrombocytopenia / Q000139:chemically induced*; D014295:Trimethoprim / Q000009:adverse effects*
chemical_list: D001779:Blood Coagulation Factors; D010977:Platelet Factor 3; D014295:Trimethoprim; D013420:Sulfamethoxazole