opioid

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opioid

 [o´pe-oid]
1. any synthetic narcotic that has opiate-like activities but is not derived from opium.
2. denoting naturally occurring peptides, such as enkephalins, that exert opiate-like effects by interacting with opiate receptors of cell membranes. See also opioid analgesic.

o·pi·oid

(ō'pē-oyd),
Originally, a term denoting synthetic narcotics resembling opiates but increasingly used to refer to both opiates and synthetic narcotics.

opioid

/opi·oid/ (o´pe-oid)
1. any synthetic narcotic that has opiate-like activities but is not derived from opium.
2. any of a group of naturally occurring peptides, e.g., enkephalins, that bind at or otherwise influence opiate receptors, either with opiate-like or opiate antagonist effects.

opioid

(ō′pē-oid′)
n.
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.

opioid

[ō′pē·oid]
Etymology: Gk, opionm, poppy juice, eidos, form
strictly speaking, pertaining to natural and synthetic chemicals that have opium-like effects similar to morphine, though they are not derived from opium. Examples include endorphins or enkephalins produced by body tissues or synthetic methadone. Morphine and related drugs are often included in this category because the term narcotic has lost its original meaning.

opioid

adjective Referring to opium-like activity, especially on receptors.
 
noun
(1) A drug that has narcotic effects similar to opium (Papaver somniferum) but is not derived from it.
(2) An endogenous peptide (e.g., endorphin) that acts on opioid receptors.

opioid

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.
Opioids
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® 

o·pi·oid

(ō'pē-oyd)
A narcotic substance, either natural or synthetic.

Opioid

Any morphine-like synthetic narcotic that produces the same effects as drugs derived from the opium poppy (opiates), such as pain relief, sedation, constipation and respiratory depression.
Mentioned in: Anesthesia, General

opioid

any non-morphine-derived narcotic drug, or naturally occurring substance with an opiate-like therapeutic action

o·pi·oid

(ō'pē-oyd)
Originally, synthetic narcotics resembling opiates but increasingly used to refer to both opiates and synthetic narcotics.

opioid

1. any synthetic narcotic that has opiate-like activities but is not derived from opium.
2. denoting naturally occurring peptides, e.g. enkephalins, that exert opiate-like effects by interacting with opiate receptors of cell membranes.

endogenous opioid
opioid receptors
specific receptor sites for opioids, named for the drugs which have a high binding affinity for them. The main ones are mu (morphine), kappa (opioid agonist-antagonists such as pentazocine) and delta (enkephalin endogenous opioids). Subtypes exist and others, such as sigma and epsilon, have been identified.