Abstract
There has been much publicity, particularly in Europe, regarding a new phenylethylamine-based compound called 4-methylthioamphetamine (4-MTA), also known as para-methylthioamphetamine (p-MTA), MTA or 'Flatliner'. Chemically, 4-MTA is an amphetamine derivative and is a potent, non-neurotoxic serotoninreleasing agent and reversible inhibitor of rat monoamine oxidase-A. Its effects, therefore, appear different from those of amphetamine.
Analysis of various plasma and urine specimens in three clinical cases implicating 'Ecstasy' ingestion revealed the presence of 4-MTA. Presumed metabolites were also detected, with one compound identified as being 4-MTA sulphoxide. The concentrations of 4-MTA measured in the plasma ranged from 0·131mg/L to 0·760mg/L. In one patient the 4-MTA concentration was determined in a series of plasma samples and this allowed a presumptive half-life of approximately 7h to be estimated. This paper describes the first reported data regarding possible pharmacokinetics of 4-MTA in humans and presents the first reported non-fatal instances of 4-MTA intoxication in the UK.