Also found in: Dictionary, Thesaurus, Encyclopedia.


Neurology A pain-attenuating peptide that occurs naturally in the brain, which induces analgesia by mimicking endogenous opioids at opioid receptors in the brain. See Opioid-mediated analgesia system.
Agonists The most potent opioid agonists are morphine, meperidine, methadone; other opioids include hydromorphine–Dilaudid®, codeine, oxycodone–Percodan®, propoxyphene–Darvon®
Antagonists Naloxone–Narcan®
Mixed agonsts-antagonists Pentazocine–Talwin® 
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
In recent studies (6), no difference was found between GnRH antagonists and GnRH agonists in terms of live birth rates.
"We actually found the protagonists were performing a greater amount of violence per hour than the antagonists. Protagonists were performing 22.7 violent events per hour, while the antagonists, or bad guys, were performing 17.5 events per hour," said John Muller, lead researcher of the project.
PPI and histamine-2 receptor antagonist use were identified from Medicare Part D claims covering three years prior to the index date.
Psychopaths, as portrayed, are convenient antagonists, chameleon-like, intelligent, and utterly devoid of emotion.
M2 PHARMA-March 14, 2018-Sosei Recovers Worldwide Rights to CGRP Antagonists for Migraine and Other Headaches
Studies that did not use animals, did not evaluate CINP, or evaluated noncannabinoid compounds without using cannabinoid receptor antagonists, reviews, commentaries, and in vitro studies were excluded.
In nonpregnant women, angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists are popular first-line therapies for primary hypertension.
Seven known fungal and bacterial bio agents (antagonists) viz., Trichoderma viride Pers, ex.
People who take proton pump inhibitors for stomach acid reflux run a greater risk of chronic kidney disease than those who take H2-receptor antagonists for the same complaint, a new study published in Gastroenterology reports.
Several studies have reported conflicting results regarding the outcome of COS-IUI cycles using GnRH antagonists in terms of clinical pregnancy rate.
Aprepitant belongs to a class of agents known as NK1 receptor antagonists, which are often used in combination with 5-HT3 receptor antagonists for the prevention of CINV.