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depressant

 
Dictionary: de·pres·sant   (dĭ-prĕs'ənt) pronunciation
adj.
Tending to lower the rate of vital physiological activities.

n.
An agent, especially a drug, that decreases the rate of vital physiological activities.


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Antonyms: depressant
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n

Definition: sedative
Antonyms: stimulant


Dental Dictionary: depressant
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(dēpres′ənt)
n

A medicine that diminishes functional activity.

 
Columbia Encyclopedia: depressant
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depressant, 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. Some are primarily used medically to relieve emotion stress, anxiety, and tension; others induce sleep, and still others are used to relieve pain. Depressants also reduce the rate and force of contraction of the heart and are used in the treatment of some forms of heart disease. Many depressants can induce psychological dependence and addiction (see drug addiction and drug abuse). Typically, overdosage results in confusion, coma, and convulsions. In many cases, the effects of one depressant are intensified if another depressant is taken at the same time, e.g., if barbiturates are taken with alcohol. Because of their potential for abuse, there are now strict regulations regarding the dispensing of many depressant drugs.


Veterinary Dictionary: depressant
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1. diminishing any function or activity.
2. an agent that retards any function, especially a drug that acts on the central nervous system to depress activity at all levels by stabilizing neuronal membranes. CNS depressants, e.g. barbiturates and inhalational anesthetics, are used as sedatives, hypnotics and anesthetics.

Word Tutor: depressant
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pronunciation

IN BRIEF: Something that lowers the rate of activities in the body.

pronunciation Alcohol acts as a stimulant for some people, a depressant for others.

Wikipedia: Depressant
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Depressants are psychoactive drugs which temporarily diminish the function or activity of a specific part of the body or mind.[1] Examples of these kinds of effects may include anxiolysis, sedation, and hypotension. Due to their effects typically having a "down" quality to them, depressants are also occasionally referred to as "downers". Stimulants or "uppers", which increase mental and/or physical function, are in stark contrast to depressants and are considered to be their functional opposites. Depressants are widely used throughout the world as prescription medicines and as illicit substances. When these are used, effects may include anxiolysis, analgesia, sedation, somnolence, cognitive/memory impairment, dissociation, muscle relaxation, lowered blood pressure/heart rate, respiratory depression, anesthesia, and anticonvulsant effects. Some are also capable of inducing feelings of euphoria. Depressants exert their effects through a number of different pharmacological mechanisms, the most prominent of which include facilitation of GBA and/or opioid activity, and inhibition of adrenergic, histamine and/or acetylcholine activity.

Contents

Indications

Depressants are used both individually and clinically for therapeutic purposes in the treatment of a number of indications, including the following :

  • To reduce feelings of anxiety, panic, and stress.
  • To induce sleepiness and relieve insomnia.
  • To induce analgesia and relieve aches and pains.
  • To reduce convulsions/seizures in the treatment of epilepsy.
  • To cause muscle relaxation for those with muscle pain or spasms.
  • To lower blood pressure and/or heart rate.
  • To boost the mood and/or enhance sociability.

Types

Alcohol

Some typical alcoholic beverages.

Barbiturates

Barbiturates are effective in relieving the conditions they are designed to address; they are also readily abused, physically addictive, and have serious potential for overdose. When, in the late 1960s, it became clear that the social cost of barbiturates were beginning to outweigh the medical benefits, a serious search began for a replacement drug. (See Methaqualone) Most people still using barbiturates today do so in the prevention of seizures or in mild form for relief from the symptoms of migraines.

Benzodiazepines

Benzodiazepines mediate many of the same symptoms as barbiturates, and in addition, they are generally less toxic and have a strongly reduced risk of overdose.Temazepam and some other benzodiazepine sleeping medications have a high index of toxicity, as measured by the number of deaths and coma incidents per million prescriptions, compared to other benzodiazepines and even some tricyclic antidepressants, because they are frequently used in suicide attempts. So it is advised to be careful with prescriptions of those sleeping medications to patients at a risk of suicide.[2] However, most other benzodiazepines are generally far less toxic and have a strongly reduced risk of overdose. This is not to say they are not without their own risks; where barbiturates pose a greater "front-end" danger in that overdose or drug/alcohol interactions may result in fatality, benzodiazepines pose a greater "back-end" risk in the possibility of addiction, dependence, and serious physical and psychological withdrawal symptoms. Immediate cessation of long-term benzodiazepine use instead of tapering can be dangerous and have serious effects. Besides temazepam, other strong hypnotic benzodiazepines such as nitrazepam, flunitrazepam, triazolam, flutoprazepam and nimetazepam have been shown to cause marked sedation along with hypotension, respiratory depression, and death (with or without the use of ethanol or other CNS depressants, though the chances of overdose and death are greatly increased when consuming a benzodiazepine along with another CNS depressant).[3]

Others

Combinations

Combining multiple depressants is generally recognized as very dangerous because the CNS depressive properties has been proposed to increase exponentially instead of linearly. This characteristic makes depressants a common choice for deliberate overdoses in the case of suicide. The use of alcohol or benzodiazepines along with the usual dose of heroin is often the cause of overdose deaths in opiate addicts.

See also

Diagram of categories of psychoactive drugs

References

  1. ^ "MSDS Glossary". http://www.utexas.edu/safety/ehs/msds/glossary/?page=d. Retrieved 2009-01-01. 
  2. ^ Buckley NA, Dawson AH, Whyte IM, O'Connell DL. (1995). "[Relative toxicity of benzodiazepines in overdose.]". BMJ 310 (6974): 219–21. PMID 7866122. PMC 2548618. http://www.bmj.com/cgi/content/full/310/6974/219. 
  3. ^ Serfaty M, Masterton G (1993). "Fatal poisonings attributed to benzodiazepines in Britain during the 1980s". Br J Psychiatry 163: 386–93. doi:10.1192/bjp.163.3.386. PMID 8104653. 

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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
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Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.  Read more
Columbia Encyclopedia. The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2003, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/ Read more
Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.  Read more
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