Evaluation of Roche Abuscreen ONLINE amphetamine immunoassay for screening of new amphetamine analogues

Some structural analogues of amphetamine are now important drugs of abuse in Thailand. The utility of the Roche Abuscreen ONLINE reagent amphetamine immunoassay test kit to detect these analogues was studied. The test showed high cross-reactivity to 3,4-methylenedioxyamphetamine (MDA), but low cross-reactivity to its parent drugs, 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA), as well as to methamphetamine and ethylamphetamine. Also observed in this study was a methamphetamine detection sensitivity enhancement effect of amphetamine, which is the active metabolite of methamphetamine. Correlation between the measured concentration values and the actual amount of these two drugs in the sample was, however, low. Thus, the test can be used to detect methamphetamine only when amphetamine is also present in the sample resulting from either co-administration or metabolism of methamphetamine.