barbiturate


barbiturate
/bahr bich"euhr it, -euh rayt'; bahr'bi toor"it, -ayt, -tyoor"-/, n. Pharm.
any of a group of barbituric acid derivatives, used in medicine as sedatives and hypnotics.
[1925-30; BARBITUR(IC) + -ATE2]

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Any of a class of heterocyclic compounds based on the parent structure, uric acid, and used in medicine.

They depress the central nervous system, acting particularly on certain parts of the brain, though they tend to depress the functioning of all the body's tissues. Long-acting barbiturates (e.g., barbital and phenobarbital) are used to treat epilepsy. Intermediate ones (e.g., amobarbital) are used to treat insomnia, short-acting ones (e.g., pentobarbital) to overcome difficulty in falling asleep (one aspect of insomnia), and ultra-short-acting ones (e.g., thiopental sodium) to induce unconsciousness in surgical patients before administration of other anesthetics. Prolonged use of barbiturates may lead to addiction. Sudden withdrawal can be fatal; addicts must be weaned from the drug under medical supervision. Overdoses can result in coma and even death; barbiturates are particularly dangerous, even at normal doses, when combined with alcoholic beverages.

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      any of a class of organic compounds used in medicine as sedatives (sedative-hypnotic drug) (to produce a calming effect), as hypnotics (to produce sleep), or as an adjunct in anesthesia. Barbiturates are derivatives of barbituric acid (malonyl urea), which is formed from malonic acid and urea. Barbital was first synthesized in 1903, and phenobarbital became available in 1912. Barbiturates act by depressing the central nervous system, particularly on certain portions of the brain, though they tend to depress the functioning of all the body's tissues. Most of them exert a sedative effect in small doses and a hypnotic effect in larger doses.

      Barbiturates are classified according to their duration of action. The effects of long-acting barbiturates, such as barbital and phenobarbital, may last for as long as 24 hours; these drugs are used in conjunction with other drugs for the treatment of epilepsy, in which their prolonged depressant action helps prevent convulsions. Barbiturates of intermediate duration of action, such as amobarbital and butabarbital sodium, act for 6 to 12 hours and are used to relieve insomnia. Short-acting barbiturates, such as pentobarbital and secobarbital, are used to overcome difficulty in falling asleep. Ultrashort-acting barbiturates, such as thiopental sodium and thiamylal, are used intravenously to induce unconsciousness smoothly and rapidly in patients about to undergo surgery, after which gaseous anesthetics are used to maintain the unconscious state. The barbiturates have largely been replaced as sedatives by the benzodiazepines and other minor tranquilizers.

      The prolonged use of barbiturates—especially secobarbital and pentobarbital—may cause the development of a tolerance to them and require amounts much larger than the original therapeutic dose. Denial of a barbiturate to the habitual user may precipitate a withdrawal syndrome that is indicative of physiological dependence on the drug. An overdose of barbiturates can result in coma and even death due to severe depression of the central nervous and respiratory systems.

      The abuse (drug abuse) of barbiturate drugs became highly prevalent in Western societies between the 1940s and '70s. In North America barbiturates were widely used by youth gangs (gang) and deviant subcultures as depressants and attracted notoriety because they were often taken in combination with other substances (e.g., stimulants such as amphetamines). Alcohol greatly intensifies the depressant effect of barbiturates, and in the 1950s and '60s, barbiturates taken with alcohol became a common agent in suicide cases. Collectively, barbiturates became known as “thrill-pills” or “goofballs,” and they became a frequent target of anti-drug campaigns. The use and availability of barbiturates in the United States declined steeply following the federal Comprehensive Drug Abuse Prevention and Control Act of 1970. As a street drug, barbiturates were largely replaced by other substances during the 1970s, especially by PCP.

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Universalium. 2010.

Look at other dictionaries:

  • Barbiturate — sind Derivate der Barbitursäure, allerdings keine Salze oder Ester, wie der Name suggeriert. Die meist aliphatischen Substituenten sind gewöhnlich am C5 der Barbitursäure zu finden. Barbitursäure wurde erstmals 1864 von Adolf von Baeyer… …   Deutsch Wikipedia

  • barbiturate — index narcotic Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • barbiturate — [baʀbityʀat] n. m. ÉTYM. 1898, Larousse; de barbitur(ique), et ate. ❖ ♦ Chim., pharm. Sel ou ester de l acide barbiturique. || Usage thérapeutique des barbiturates. ⇒ Barbiturique. || Intoxication par les barbiturates …   Encyclopédie Universelle

  • Barbiturate — Barbiturate,   Singular Barbiturat das, s, die (therapeutisch verwendeten) Abwandlungsprodukte der Barbitursäure …   Universal-Lexikon

  • barbiturate — 1928, from German, coined 1863 by chemist Adolf von Baeyer (1835 1917) from Barbitursäure barbituric acid, coined by Baeyer, perhaps from woman s name BARBARA (Cf. Barbara), or perhaps from L. barbata, in M.L. usnea barbata, lit. bearded moss.… …   Etymology dictionary

  • barbiturate — ► NOUN ▪ any of a class of sedative drugs related to a synthetic compound (barbituric acid) derived from uric acid. ORIGIN from barbituric acid, from German Barbitursäure, from the name Barbara + Ursäure uric acid …   English terms dictionary

  • barbiturate — [bär bich′ər it, bär bich′ə rāt΄; bär΄bə tyoor′it, bär΄bətoor′it, bär΄bə tyo͞or′āt΄ bär΄bə toor′āt΄; ] often [, bär΄bich′ə wit] n. [ BARBITURIC ACID + ATE2] any depressant drug, as phenobarbital, derived from barbituric acid and used as a… …   English World dictionary

  • Barbiturate — Barbiturates are drugs that act as central nervous system depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia. They are also effective as anxiolytics, hypnotics and as anticonvulsants. They …   Wikipedia

  • barbiturate — UK [bɑː(r)ˈbɪtʃʊrət] / US [bɑrˈbɪtʃərət] noun [countable] Word forms barbiturate : singular barbiturate plural barbiturates medical a strong drug that doctors give to people to make them calm or help them sleep …   English dictionary

  • barbiturate — A derivative of barbituric acid, including phenobarbital and others, that act as CNS depressants and are used for their tranquilizing, hypnotic, and anti seizure effects; most barbiturates have the potential for abuse. * * * bar·bi·tu·rate bär… …   Medical dictionary


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