title: Doxylamine: a cause for false-positive gas chromatographic assay for phencyclidine.
abstract: A 25-year-old white woman ingested an unknown quantity of doxylamine succinate and flurazepam. Urine immunoassay screen (EMIT-dau) was positive for benzodiazopine and negative for phencyclidine. Subsequent gas chromatographic assay of the urine revealed a markedly positive assay for phencyclidine. Doxylamine was ultimately found to be the cause for the false-positive gas chromatographic assay for phencyclidine.
mesh_terms: D000328:Adult; D002849:Chromatography, Gas; D004319:Doxylamine / Q000652:urine*; D005189:False Positive Reactions; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D010622:Phencyclidine / Q000652:urine*; D011725:Pyridines / Q000652:urine*
chemical_list: D011725:Pyridines; D004319:Doxylamine; D010622:Phencyclidine