Chemists and physicians have always been seeking chemical compounds that are characterized as hypnotics, or sleeping compounds. Toward the end of the 19th century, with the beginning of discoveries in chemistry, doctors were prescribing compounds such as paraldehyde, chloral hydrate and bromides. It is documented that in the s, the wife of Abraham Lincoln, Mary Todd Lincoln was given chloral hydrate for her sleep problems.
By the end of the 19th century, chemistry was advancing to a level where it began extracting and combining compounds to make new drugs that were used experimentally in humans to establish their effects in the hopes of finding cures for various maladies of life.
The history of the development of barbiturates is as bizarre as the effects of the drug itself and its consequences in history. Its founder was a German chemist, Adolph von Baeyer, the person who founded Bayer Chemicals Company, which is still a major manufacturer of analgesics and well-known and criticized for many of its pesticides and fertilizers. In , he was working on the synthesis of a drug using urea and malonic acid, a chemical found in apples.
This synthetic drug became known as barbituric acid, named after St. In this case, there were no signs of any therapeutic significance in his discovery. When given to humans, it induced sleep and was one of the first hypnotic drugs. A term used to generically categorize chemicals that induce sleep. The next important step was the development of barbiturates.
The pioneers were Josef von Mering and Emil Fischer. Using the Grimaux-method they synthesized various barbiturates.
It was von Mering who got the idea of introducing ethyl groups in the inactive barbituric acid to obtain sedatives, but the synthesis was succeeded by the chemist Emil Fischer.
Experiments with dogs clearly showed sedative and hypnotic effect of the barbiturates and the oral administration of barbital Veronal confirmed the effect in humans.
Barbital was commercialized in and in phenobarbital Luminal was introduced in the clinic, and this drug showed hypnotic and antiepileptic effects. The delirium resembles that sometimes seen during alcohol withdrawal delirium tremens and involves anxiety, disorientation and visual hallucinations. During the delirium, agitation and hyperthermia can lead to exhaustion, cardiovascular collapse and death. But this is not inevitable and the symptoms can disappear with time typically after eight days or so.
The synthesis of barbiturates is mostly performed by the pharmaceutical and chemical industry, but descriptions of their synthesis from appropriate malonyl esters and urea appear on the Internet. Barbiturates are usually swallowed as tablets but can be injected for both medical and non-medical purposes.
Numerous synonyms and proprietary names exist for the various barbiturates. User names include barbs, downers, Christmas trees, blue heavens, blues, goof balls, blockbusters, pinks, rainbows, reds, red devils, reds and blues, sekkies, sleepers, yellow jackets, etc.
Barbiturates give violet colours with a mixture of ethanolic cobalt nitrate and pyrrolidine Koppanyi-Zwikker test. The major ions for amobarbital molecular weight Twelve barbiturates are subject to international control through the UN Convention on Psychotropic Substances see Table 1. Secobarbital was transferred from Schedule III to Schedule II in because of diversion from licit manufacture into the illicit trade. Amobarbital, cyclobarbital and pentobarbital were included in Schedule III in , with butalbital added in The remaining compounds are in Schedule IV.
Thiopental CAS is not subject to international control. The International Narcotics Control Board INCB reported that in , total global licit production of barbiturates amounted to at least metric tons, tons of which was phenobarbital.
Just five of the 12 barbiturates under international control accounted for Ultra-short-acting compounds such as thiopental, which is an analogue of pentobarbital where the oxygen at position 2 is replaced by sulphur CAS , and methohexital CAS are used for anaesthesia, while long-acting derivatives such as phenobarbital are used in the treatment of epilepsy and other types of convulsions. Phenobarbital may be used in the treatment of withdrawal symptoms in neonates of mothers suffering from multiple substance dependence during pregnancy.
It is the substance of choice for the treatment of neonatal abstinence syndrome in cases of combined dependence or benzodiazepine dependence. In veterinary medicine, pentobarbital is used as an anaesthetic and in euthanasia. Brunton, L. Buckley, N.
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