Fatal poisoning with a new phenylethylamine: 4-methylthioamphetamine (4-MTA)

There has been much publicity in the United Kingdom 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 non-neurotoxic potent serotonin- releasing agent and reversible inhibitor of rat monoamine oxidase-A. Analysis of postmortem blood and urine specimens in a case implicating 3,4- methylenedioxymethamphetamine revealed the presence of 4-MTA at a concentration of 4.6 mg/L in femoral blood and 87.2 mg/L in the urine. The concentration of 4-MTA in perimortem blood was measured at 4.2 mg/L. This is the first reported case of death involving 4-MTA in the United Kingdom and the first case known to involve 4-MTA only.