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(pârăl`dəhīd'), nervous system depressantdepressant,
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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 similar to alcohol in its effects and used as a sedativesedative,
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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. A colorless flammable liquid with a disagreeable odor, paraldehyde produces sleep for up to 12 hr. with little or no muscle, heart, or respiratory depression. It is often given to alcoholics having delirium tremens, to induce sleep, and is also used to calm psychiatric patients. Like alcohol and other depressants it is 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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). Paraldehyde is also used in the manufacture of synthetic resins, as a preservative, and in preparing leather. It is produced by treating acetaldehyde with a small amount of sulfuric acid.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a trimer of acetaldehyde. Colorless liquid, boiling point 1240C. The structure of paraldehyde is

The compound readily depolymerizes upon heating with a small quantity of sulfuric acid, and is thus a convenient storage form of acetaldehyde. Paraldehyde exhibits a weak narcotic effect.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(organic chemistry)
C6H12O3 Acetaldehyde polymer; colorless, flammable, toxic liquid, miscible with most organic solvents, soluble in water; melts at 12.6°C, boils at 124.5°C; used as a chemical intermediate, in medicine, and as a solvent.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
We used barbiturates and paraldehyde for the particularly uncooperative.
Endothermic agents include oxidized and unoxidized polymers; carbon monoxide-bonded copolymers; polyethylene waxes; stearamides; tars; high-molecular-weight oils; polyvinyl alcohol; carnauba wax; metallic hydroxides; boric acid; dodecaborane; paraldehyde; paraformaldehyde; trioxane; acetates; carbonates; salts; and hydrates.
prescribed Hoffman's anodyne and paraldehyde to treat her nervous
Intravenous diazepam achieved quicker sedation of patients compared with rectal paraldehyde in one study, and there was no difference in sedation times between intramuscular diazepam and oral barbital in another, said Dr.
Intravenous diazepam achieved quicker sedation of patients, compared with rectal paraldehyde in one study, and there was no difference in sedation times between intramuscular diazepam and oral barbital in another, said Dr.
domesricus is suggested by earlier work showing that ovariectomy results in a decrease in the amount of paraldehyde fuchsin (PAF) positive material in the PIC and decreased levels of several PAF positive polypeptides in the brain and corpora cardiaca (Bradley and Simpson, 1981).
Pharmacokinetics and clinical use of parenteral phenytoin, phenobarbital, and paraldehyde. Epilepsia 1989; 30(Suppl 2):S1-3.
At the inquest, the Coroner's Jury ruled the cause of death was 'cardiac arrest.' For some reason, the Queen Street psychiatrists prescribed a lot of paraldehyde to Davis, as well as Nozinan and Valium.