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Related to Opioid receptors: Opioid Analgesics


Any of various compounds that bind to specific receptors in the central nervous system and have analgesic and narcotic effects, including naturally occurring substances such as morphine; synthetic and semisynthetic drugs such as methadone and oxycodone; and certain peptides produced by the body, such as endorphins. Also called opiate.

o′pi·oid′ adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


a. any of a group of substances that resemble morphine in their physiological or pharmacological effects, esp in their pain-relieving properties
b. (modifier) of or relating to such substances: opioid receptor; opioid analgesic.
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈoʊ piˌɔɪd)

1. any opiumlike substance, as the endorphins produced by the body or the synthetic compound methadone.
2. pertaining to such a substance.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


adj & n opioide m
English-Spanish/Spanish-English Medical Dictionary Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
References in periodicals archive ?
Naltrexone competitively antagonizes opioid receptors with the highest affinity for the jj-opioid receptor.
The term "opioid" refers to all drugs that act primarily on opioid receptors in the body, including synthetic drugs--those containing no natural opium derivatives.
Abstract: To further knowledge of the physiology of opioid receptors in birds, the structure and expression of the [mu]-, [delta]-, and [kappa]-opioid receptor genes were studied in a peregrine falcon (Falco peregrinus), a snowy owl (Bubo scandiacus), and a blue-fronted Amazon parrot (Amazona aestiva).
The scientists are working with chemists to develop new drugs that may be able to target both the human Mrg receptor and opioid receptors at the same time.
After evaluating the effects of morphine and meperidine on the amplitude and frequency of proximal and distal colon, the same experiments were repeated in the presence of [10.sup.-5] [M] (mol [L.sup.-1], molar) naloxone to see the role of opioid receptors in the observed effect.
However, in low doses, naltrexone acts to temporarily block opioid receptors. The body responds by producing increased amounts of endorphins and enkephalins.
These compounds attach to and stimulate the mu-opioid receptor in the brain, creating positive reinforcement, while blocking the pain-relieving effect on two other opioid receptors.
More commonly known as Imodium, loperamide is an anti-diarrhea medication that acts on opioid receptors in the intestines to decrease the number of bowel movements.
Despite the indisputable evidence regarding the contribution of the opioid system to pain modulation, some studies have also suggested that the activity of opioid receptors is more associated with the learning prediction over time rather than the painful outcome [54].
Opioid receptors even an extrahepatic opioid receptor-associated mechanism may participate in this protection [9, 10].
* Systemic pain as the opioid receptors in their brain are no longer occupied by the opioid drug.
Selective opioid receptor agonists: These agents target kappa- and/or mu-opioid receptors on peripheral pain-sensing neurons in order to inhibit itch without activating other opioid receptors linked to classic opioid side effects such as respiratory depression, constipation, and addiction.