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 ?
One or more Rapid Drug Screen test cards are inserted into the urine through a safety-sealed slit in the cup lid and, in minutes, indicate the presence or absence of the drugs covered by the cards: cocaine, opiates, marijuana, PCP, barbituates, benzodiazepines, tricyclic antidepressants, methamphetamine, amphetamines and methadone individually or in various combinations.
He had become addicted to barbituates and alcohol during his time in combat, drugs that numbed his conscience, that gave him just enough "crazy" to climb into a chopper and kill Vietnamese people every day, firing into trees as the helicopter zoomed past at 100 mph.
On April 17, 2001, Gifford-Meyers was found dead from an overdose of barbituates in a Pasco County park.
He popped barbituates by the handful from five different bottles.