This MedLibrary.org supplementary page on Anticholinergic is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
 |
This article does not cite any references or sources. (January 2008) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
An anticholinergic agent is a substance which blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicyclomine. Generally speaking, it reduces the effects mediated by acetylcholine on acetylcholine receptors in neurons through competitive inhibition. The effect is therefore reversible.
Anticholinergics are classified according to the receptors that are affected:
- Antimuscarinic agents operate on the muscarinic acetylcholine receptors. The majority of anticholinergic drugs are antimuscarinics.
- Antinicotinic agents operate on the nicotinic acetylcholine receptors.
|
|
This article does not cite any references or sources. (June 2008) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
Contents |
Effects
|
|
This section does not cite any references or sources. (June 2008) Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
When a significant amount of an anticholinergic is taken into the body, a toxic reaction known as acute anticholinergic syndrome may result. This may happen accidentally or intentionally as a consequence of recreational drug use. Anticholinergic drugs are usually considered the least "fun" by experienced recreational drug users, possibly due to the lack of euphoria caused by them. (For some of the "recreational" effects, see the article on deliriants.) Because most users do not enjoy the experience, they do not use it again, or do so very rarely. The risk of addiction is low in the anticholinergic class. The effects are usually more pronounced in the elderly, due to the decrease of acetylcholine production associated with age.
Possible effects of anticholinergics include:
- Ataxia; loss of coordination
- Decreased mucus production in the nose and throat; consequent dry, sore throat
- Xerostomia or dry mouth with possibly acceleration of caries
- Cessation of perspiration; consequent decreased thermal dissipation through the skin leading to hot, red skin
- Increased body temperature
- Pupil dilation (mydriasis); consequent sensitivity to bright light (photophobia)
- Loss of accommodation (loss of focusing ability, blurred vision — cycloplegia)
- Double vision (diplopia)
- Increased heart rate (tachycardia)
- Urinary retention
- Diminished bowel movement, sometimes ileus
- Increased intraocular pressure, dangerous for people with narrow-angle glaucoma
- Shaking
Possible effects in the central nervous system resemble those associated with delirium, and may include:
- Confusion
- Disorientation
- Agitation
- Respiratory depression
- Short-term memory loss
- Inability to concentrate
- Wandering thoughts; inability to sustain a train of thought
- Incoherent speech
- Wakeful myoclonic jerking
- Unusual sensitivity to sudden sounds
- Illogical thinking
- Photophobia
- Visual disturbances
- Periodic flashes of light
- Periodic changes in visual field
- Visual snow
- Restricted or "tunnel vision"
- Visual, auditory, or other sensory hallucinations
- Warping or waving of surfaces and edges
- Textured surfaces
- "Dancing" lines; "spiders", insects
- Lifelike objects indistinguishable from reality
- Hallucinated presence of people not actually there
- Rarely: seizures, coma and death
Acute anticholinergic syndrome is completely reversible and subsides once all of the toxin has been excreted. Ordinarily, no specific treatment is indicated. However, in extreme cases, especially those that involves severe distortions of mental state, a reversible cholinergic agent such as physostigmine may be used.
Plant sources
The most common plants containing anticholinergic alkaloids are:
- Atropa belladonna (Deadly Nightshade)
- Brugmansia species (Brugmansia)
- Datura species (Datura)
- Hyoscamus niger (Henbane)
- Mandragora officinarum (Mandrake)
Use as a deterrent
Certain preparations of some drugs, such as Hydrocodone, are mixed with an anticholinergic agent to deter intentional overdose. [1]
External links
- National Library of Medicine - Medical Subject Headings: MeSH Anticholinergics
|
|||||||||||
|
|||||||||||||||||
|
|||||||||||||||||||||||||||||||||
|
|||||||||||
|
||||||||||||||||||||||||||
|
||||||||
|
|||||||||||||||||||||||||||||
Wikipedia content modification information:
- This page was last modified on 1 July 2008, at 22:06.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Anticholinergic".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.