This MedLibrary.org supplementary page on Dissociatives 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
A dissociative is a drug which reduces (or blocks) signals to the conscious mind from other parts of the brain, typically, but not necessarily, limited to the senses. Such a state of sensory deprivation and dissociation can facilitate self-exploration, hallucinations, and dreamlike states of mind which may resemble some psychedelic mindstates. Essentially, similar states of mind can be reached via contrasting paths—psychedelic or dissociative. That said, the entire experience's risks and benefits are markedly different.
The primary dissociatives are similar in action to phencyclidine (PCP), and include ketamine and dextromethorphan (DXM). Also included are nitrous oxide (laughing gas), salvia divinorum, and muscimol from the amanita muscaria (fly agaric) mushroom.
Many dissociatives also have central nervous system depressant effects, thereby carrying similar risks with opioids that slow breathing and lower the heart rate to levels which can result in death, when used in very high doses.
Their effects are characterized by intense feelings of depersonalization, derealization, and analgesia.
Contents |
Pharmacological classes of dissociatives, and their general subjective effects
Entries marked with a # are naturally occurring.
NMDA Receptor Antagonists
Uncompetitive channel blockers include:
- Amantadine 1
- AP5 (2-amino-5-phosphonopentanoate), a competitive glutamate antagonist selective for the NMDA-R.
- Dextromethorphan
- Dextrorphan
- Ibogaine # 2
- Phencyclidine
- Ketamine
- Tiletamine
- Rolicyclidine
- Eticyclidine
- Tenocyclidine
- Dizocilpine
- Nitrous oxide #
- Xenon #
- Riluzole
Most members of the noncompetitive channel-blocker group are arylcyclohexylamines. Their molecular structure includes a cyclohexyl ring, a piperidine ring and a phenyl group. 3 The gases nitrous oxide and xenon are obvious exceptions Non-competitive antagonists include:
- Aptiganel (Cerestat, CNS-1102). Binds the Mg2+ binding site within the channel of the NMDAR.
- Memantine (Axura, Akatinol, Namenda, Ebixa, 1-amino-3,5-dimethylada-mantane). Approved in the U.S. by the Food and Drug Administration for the treatment of Alzheimer's disease.4
- Remacimide. Principle metabolite is an uncompetitive antagonist with a low affinity for the binding site.5
Drugs that act at the glycine binding site include 7-chlorokynurenate.
κ-opioid receptor agonists
- Salvinorin-A #, the active constituent of Salvia divinorum (diviner's sage)
- Enadoline
- ibogaine (Weak / Complex mechanism of action)
- Pentazocine
σ-opioid receptor agonists
Amanita muscaria constituents
- Muscimol # GABA-A agonist, primary active constituent
- Ibotenic acid # NMDA agonist, neurotoxin, metabolizes to muscimol or can be converted into muscimol by heating at 170 C
- Muscarine # muscarinic ACh agonist, trace constituent, not active in brain but causes physical side effects
These four groups of dissociatives have slightly different effects but also share similarities separating them from other classes of hallucinogens. They are markedly different from psychedelics such as LSD, where alert and fully conscious users experience cognitive distortion while simultaneously interacting with the "real world". Hallucinations from these dissociatives are generally only experienced in dark rooms or with eyes closed, unless at very high doses above what is normally consumed recreationally. Nitrous oxide has very different effects however, and even at low doses includes auditory distortions. Unlike with many other psychedelic chemicals, salvia users are generally not ambulatory and the experience is frequently dissociative. Often a very brief trance is entered, where the user experiences an intense and very realistic dream state. On the other hand, the effect of salvia on emotion has been reported to be less marked than that of true psychedelics.
Although muscimol does not usually cause normal hallucinations, it has a tendency to put the user to sleep, during which the user is able to have very vivid dreams with good dream recall.
See also
References
- ^ "Effects of N-Methyl-D-Aspartate (NMDA)-Receptor Antagonism on Hyperalgesia, Opioid Use, and Pain After Radical Prostatectomy", University Health Network, Toronto, September 2005
- ^ Popik P, Layer RT, Skolnick P (1994): "The putative anti-addictive drug ibogaine is a competitive inhibitor of [3H]MK-801 binding to the NMDA receptor complex." Psychopharmacology (Berl), 114(4), 672-4. Abstract
- ^ AJ Giannini. Drugs of Abuse--Second Edition. Los Angeles, Practice Management Information Corp, 1997.
- ^ Chawla, PS; Kochar MS (2006). "What's new in clinical pharmacology and therapeutics". WMJ 105 (3): 24–29. PMID 16749321, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16749321&query_hl=23&itool=pubmed_docsum. Retrieved on 17 January 2007.
- ^ Muir, KW (2005). "Glutamate-based therapeutic approaches: clinical trials with NMDA antagonists". Current Opinion in Pharmacology 6 (1): 53–60. doi:. PMID 16359918.
Wikipedia content modification information:
- This page was last modified on 2 October 2008, at 15:17.
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 "Dissociatives".
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.