title: Ranitidine interference with the monoclonal EMIT d.a.u. amphetamine/methamphetamine immunoassay.
abstract: The interference of ranitidine with the monoclonal EMIT d.a.u. amphetamine/methamphetamine immunoassay (ME) was investigated. Urine specimens collected from 23 patients receiving 150-300 mg of ranitidine daily were found to contain 7-271 mg/L of the drug when analyzed by Remedi automated high pressure liquid chromatography. Only patient specimens and urine samples with ranitidine added at concentrations greater than 91 mg/L gave false positive ME results. Of the 63 patient urine samples analyzed by ME, 12 gave false positive results. All false positive results occurred in the first or second void after ingestion. No false positive results occurred with the polyclonal EMIT d.a.u. amphetamine or TDx amphetamine/methamphetamine II assays.
authors.affiliation: Medical College of Virginia Hospital, Department of Pathology, Virginia Commonwealth University, Richmond 23298-0597.
authors.forename: A
authors.initials: A
authors.lastname: Poklis
authors.forename: K V
authors.initials: KV
authors.lastname: Hall
authors.forename: J
authors.initials: J
authors.lastname: Still
authors.forename: S R
authors.initials: SR
authors.lastname: Binder
mesh_terms: D000661:Amphetamine / Q000032:analysis* / Q000652:urine; D000911:Antibodies, Monoclonal / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007124:Immunoenzyme Techniques; D007202:Indicators and Reagents; D008694:Methamphetamine / Q000032:analysis* / Q000652:urine; D011899:Ranitidine / Q000032:analysis* / Q000652:urine
chemical_list: D000911:Antibodies, Monoclonal; D007202:Indicators and Reagents; D008694:Methamphetamine; D011899:Ranitidine; D000661:Amphetamine