Amphetamines are a subgroup of the substituted phenethylamine class of compounds. Substitution of hydrogen atoms results in a large class of compounds. Typical reaction is substitution by methyl and sometimes ethyl groups at the amine and phenyl sites:
History
was used 5000 years ago in China as a medicinal plant; its active ingredients are alkaloids ephedrine, pseudoephedrine, norephedrine and norpseudoephedrine. Natives of Yemen and Ethiopia have a long tradition of chewing khat leaves to achieve a stimulating effect. The active substances of khat are cathinone and, to a lesser extent, cathine. Amphetamine was first synthesized in 1887 by Romanian chemist Lazăr Edeleanu, although its pharmacological effects remained unknown until the 1930s. MDMA was produced in 1912 as an intermediate product. However, this synthesis also went largely unnoticed. In the 1920s, both methamphetamine and the dextrorotatory optical isomer of amphetamine, dextroamphetamine, were synthesized. This synthesis was a by-product of a search for ephedrine, a bronchodilator used to treat asthma extracted exclusively from natural sources. Over-the-counter use of substituted amphetamines was initiated in the early 1930s by the pharmaceutical companySmith, Kline & French, as a medicine for colds and nasal congestion. Subsequently, amphetamine was used in the treatment of narcolepsy, obesity, hay fever, orthostatic hypotension, epilepsy, Parkinson's disease, alcoholism and migraine. The "reinforcing" effects of substituted amphetamines were quickly discovered, and the misuse of substituted amphetamines had been noted as far back as 1936. During World War II, amphetamines were used by the German military to keep their tank crews awake for long periods, and treat depression. It was noticed that extended rest was required after such artificially induced activity. The widespread use of substituted amphetamines began in postwar Japan and quickly spread to other countries. Modified "designer amphetamines" gained popularity since the 1960s, such as MDA and PMA. In 1970, the United States adopted "the Controlled Substances Act" that limited non-medical use of substituted amphetamines. Street use of PMA was noted in 1972. MDMA emerged as a substitute to MDA in the early 1970s. American chemist Alexander Shulgin first synthesized the drug in 1976 and through him the drug was briefly introduced into psychotherapy. Recreational use grew and in 1985 MDMA was banned by the US authorities in an emergency scheduling initiated by the Drug Enforcement Administration. Since the mid-1990s, MDMA has become a popular entactogenic drug among the youth and quite often non-MDMA substances were sold as ecstasy. Ongoing trials are investigating its efficacy as an adjunct to psychotherapy in the management of treatment-resistant post-traumatic stress disorder.
