EVALUATION OF 6 COMMERCIAL AMPHETAMINE AND METHAMPHETAMINE IMMUNOASSAYS FOR CROSS-REACTIVITY TO PHENYLPROPANOLAMINE AND EPHEDRINE IN URINE

We evaluated six commercially available amphetamine (A) and methamphetamine (MA) immunoassays for their relative cross reactivities to isomers of phenylpropanolamine (PPA) and ephedrine (E) in urine: Syva EMIT, Abbott fluorescence polarization (FPIA), Roche, and Diagnostic Products Corporation (OPC) radioimmunoassays for A and MA. Two stereoisomers of PPA and four stereoisomers of E were tested using (1) drug-free urine spiked at 1000 mg/L or 100 mg/L of each compound and (2) 60 clinical urine specimens not containing A or MA but having varying amounts of PPA and/or E. Specimens responding greater than the 1-mg/L A or MA cutoff were defined as positive. All specimens spiked at 100 mg/L were negative by all immunoassays. All specimens spiked at 1000 mg/L were positive by EMIT and negative by FPIA, Roche A, and DPC A; 1000 mg/L /E and d-pseudo- ephedrine were also positive by Roche MA and DPC MA. Three of the 60 clinical specimens tested positive by EMIT and one specimen tested positive by DPC A and DPC MA. © 1992, Oxford University Press. All rights reserved.