barbiturate

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barbiturate

(bärbĭch`ərāt'), any one of a group of drugs that act as depressantsdepressant,
any one of various substances that diminish functional activity, usually by depressing the nervous system. Barbiturates, sedatives, alcohol, and meprobamate are all depressants. Depressants have various modes of action and effects.
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 on the central nervous systemnervous system,
network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of the animal kingdom have at least a rudimentary nervous system.
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. High doses depress both nerve and muscle activity and inhibit oxygen consumption in the tissues. In low doses barbiturates act as sedativessedative,
any of a variety of drugs that relieve anxiety. Most sedatives act as mild depressants of the nervous system, lessening general nervous activity or reducing the irritability or activity of a specific organ.
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, i.e., they have a tranquilizing effect; increased doses have a hypnotic or sleep-inducing effect; still larger doses have anticonvulsant and anesthetic activity. The mechanism of action on the central nervous system is not known. The barbiturates are all derivatives of barbituric acid, which was first prepared in 1864 by the German organic chemist Adolf von Baeyer.

The drugs differ widely in the duration of their action, which depends on the rapidity with which they are distributed in body tissues, degraded, and excreted. Ultrashort-acting barbiturates such as thiopental sodium (Pentothal) are often used as general anesthetics. Secobarbital (Seconal) and pentobarbital sodium (Nembutal) are short-acting barbiturates, amobarbital (Amytal) is intermediate in duration of action, and phenobarbital (Luminal) is a long-acting derivative.

Barbiturates are used to relax patients before surgery, as anticonvulsants, and as sleeping pills. They also are commonly abused. Taken regularly, barbiturates can be psychologically and physically addictive (see drug addiction and drug abusedrug addiction and drug abuse,
chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Traditional definitions of addiction, with their criteria of physical dependence and withdrawal (and often an underlying
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). Barbiturate addicts must be withdrawn from the drug gradually to avoid severe withdrawal symptoms such as convulsions. Overdose can cause coma or death. In the United States the manufacture and distribution of barbiturates were brought under federal control by the 1965 Drug Abuse and Control Act, and they are legally available only by prescription.

Bibliography

See publications of the Drugs & Crime Data Center and Clearinghouse, the Bureau of Justice Statistics Clearinghouse, and the National Clearinghouse for Alcohol and Drug Information.

barbiturate

[bär′bich·ə·rət]
(pharmacology)
Any of a group of ureides, such as phenobarbital, Amytal, or Seconal, that act as central nervous system depressants.

barbiturate

a derivative of barbituric acid, such as phenobarbital, used in medicine as a sedative, hypnotic, or auticonvulsant
References in periodicals archive ?
Providing the condemned with barbiturate pills to cause a quick painless death obviously does not require any trained (much less medical) personnel, and could avoid the many medical problems with injections, as well as restrictions and expiration dates on injectable drugs," suggests Banzhaf.
Despite being able to cope with LSD, the hippies encounter with methamphetamine and barbiturates proved disastrous.
They also state that mitigating measures, like the barbiturates Harrison took to control his epilepsy, cannot be used in determining whether a disability qualifies under the law.
Mt Cutkelvin Rees said of his partner's death: "He was handed the barbiturate by carers in a shot glass.
His pounds 35 "suicide kit" is designed to test the strength of barbiturates like the so-called euthansia drug Nembutal.
Primary care practitioners and patients should try to avoid the use of narcotic or barbiturate medications that may exacerbate migraine; if these drugs are necessary, patients should be advised of the risks of medication overuse and dose limits should be applied," he added.
In the sentencing hearing yesterday, Justice Roderick Howie said while Justins believed she was doing what Wylie wanted, she had misled people and was part of a "criminal enterprise" with a family friend who bought the barbiturate in Mexico.
The survey of 502 patients and 201 primary care physicians and neurologists conducted earlier this year found that 53 percent of migraine patients take triptans as the primary prescription medication for their condition, but 20 percent take barbiturates or opioids.
But critically, the report exposes an alleged conspiracy for the actress to unwittingly commit suicide with the drug Seconal, a barbiturate used to treat insomnia and relieve anxiety.
So why do headache patients still receive barbiturates, opioids, and narcotics instead of triptans?
This reorganized edition has more emphasis on the applications of organic chemistry in medicine and agriculture and other fields, new problems, has new information on catalysis, tetrahedral intermediates and their impact on drug design, carbon alkylations and their role in the preparation of barbiturates, and other additions.
Although the trip-tans are now by far the most widely recommended medications for acute migraine treatment, barbiturates, opioids, and nonspecific sedative drugs are still widely used and are causing problems for some headache patients.