Illegal or legitimate use? Precursor compounds to amphetamine and methamphetamine

The interpretation of methamphetamine and amphetamine positive test results in biological samples is a challenge to clinical and forensic toxicology f or several reasons. The effects of pH and dilution of urine samples and the knowledge about legitimate and illicit sources have to be taken into accou nt. Besides a potentially legal prescription of amphetamines, many substanc es metabolize to methamphetamine or amphetamine in the body: amphetaminil, benzphetamine, clobenzorex, deprenyl, dimethylamphetamine, ethylamphetamine , famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex , mesocarb, and prenylamine. Especially the knowledge of potential origins of methamphetamine and amphetamine turns out to be very important to preven t a misinterpretation of the surrounding circumstances and to prove illegal drug abuse. In this review, potential precursor compounds are described, i ncluding their medical use and major clinical effects and their metabolic p rofiles, as well as some clues which help to identify the sources.