Opioid

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.

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o·pi·oid (p-oid)

n.

See opiate.

adj.

Opiate.

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opi·oid adj.

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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

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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.

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endogenous opioid

see endorphin, enkephalin.

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.