Fluorescence Polarization Immunoassay Detection of Amphetamine, Methamphetamine, and Illicit Amphetamine Analogues*

Two commercial immunoassay reagents, Abbott's Amphetamine/Methamphetamine II and Amphetamine Class, were tested for their ability to detect a wide range of amphetamine-related compounds, including stereoisomers, metabolites, and illicit analogues such as MDMA, MDA, and mescaline, at concentrations from 100 to 100,000 ng/mL. The Amphetamine/Methamphetamine II reagent showed better overall performance, especially for detecting over-the-counter medications, while the Amphetamine Class reagent did not improve detection of amphetamine, methamphetamine, or illicit analogues. Some illicit analogues were reliably detected, but many others were not. The Amphetamine Class reagents are a poor choice unless detecting over-the-counter compounds is specifically needed.

Study at a glance

Abstract

The Abbott Diagnostics Amphetamine/Methamphetamine II and Amphetamine Class reagents were evaluated on the Abbott TDx for cross-reactivity to amphetamine and methamphetamine stereoisomers, several of their metabolites, and various illicit analogues, including 2-methoxyamphetamine, 4-hydroxymethamphetamine, 2,5-dimethoxy-amphetamine (DMA), 4-bromo-2,5-dimethoxyamphetamine (DOB), 4-bromo-2,5-dimethoxy-beta-phenethylamine (BDMPEA), 3,4,5-trimethoxyamphetamine (TMA), 3,4-methylenedioxy-amphetamine (MDA) N,N-dimethyl-3,4-methylenedioxy-amphetamine, N-hydroxy-3,4-methylenedioxyamphetamine (N-OH MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), 2,5-dimethoxy-4-ethylamphetamine (DOE), 2,5-dimethoxy-4-methylamphetamine (DOM), and mescaline in concentrations ranging from 100 to 100,000 ng/mL. Results demonstrate the utility of this assay for detection of several of the above compounds; unfortunately many are still not detectable. Significant differences were observed between the Amphetamine/Methamphetamine II and Amphetamine Class reagents, particularly regarding their cross-reactivity to over-the-counter medications. Detection of the drugs amphetamine, methamphetamine, and the illicit analogues is not enhanced with the Amphetamine Class reagents, and unless detection of the over-the-counter compounds is of interest, these reagents are a poor choice compared to the Amphetamine/Methamphetamine II reagents. Cross-reactivity of some of the illicit analogues is such that the assay can reliably be used for the routine screening of these compounds.