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Depressant

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Not to be confused with depression (mood).

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 used recreationally.

Effects

Depressants produce a wide variety of different kinds of effects by inhibiting the activity of the central and peripheral nervous systems. Common effects, which vary depending on the substance in question, may include anxiolysis, analgesia, sedation, somnolence, cognitive/memory impairment, dissociation, muscle relaxation, lowered blood pressure/heart rate, respiratory depression, anesthesia, 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 GABA and/or opioid activity, and inhibition of adrenergic, histamine and/or acetylcholine activity.

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.
Main article: Alcoholic Beverage
Main article: Ethanol

Barbiturates

Main article: 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 was 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

Main article: 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]

Opiates / Opioids

Main article: Opiates
Main article: Opioids

Cannabis

Main article: Cannabis (drug)

One of the most commonly used depressants in the world, cannabis has psychoactive and physiological effects when consumed. The minimum amount of tetrahydrocannabinol (THC) required to have a perceptible psychoactive effect is about 10 mg/kg of body weight. Aside from a subjective change in perception, the most common short-term physical and neurological effects include increased heart rate, lowered blood pressure, impairment of psychomotor coordination, concentration, and short-term episodic and working memory. Long-term effects are less clear.

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

References

  1. ^ "MSDS Glossary". Retrieved 2009-01-01.
  2. ^ Buckley NA, Dawson AH, Whyte IM, O'Connell DL. (1995). "[Relative toxicity of benzodiazepines in overdose.]". BMJ. 310: 219–21. PMID 7866122.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  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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