opioid antagonist


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Related to opioid antagonist: naloxone, Opioid Agonist

opioid antagonist

a drug that blocks mu, kappa, or delta opioid receptors, used primarily in the treatment of opioid-induced mu receptor-mediated respiratory depression. The opioid antagonist naloxone is administered parenterally, whereas naltrexone is administered orally.

o·pi·oid an·tag·o·nist

(ō'pē-oyd an-tag'ŏ-nist)
Examples include naloxone and naltrexone that have high affinity for opiate receptors but do not activate these receptors. These drugs block the effects of exogenously administered opioids (e.g., morphine, heroin, meperidine, and methadone), or of endogenously released endorphins and enkephalins.
References in periodicals archive ?
Access to opioid antagonists empowers community members to effectively respond during an overdose emergency and increases the likelihood that individuals struggling with addiction can be directed to treatment resources.
And therefore, it is not surprising that we found that naloxone, an opioid antagonist induced hypophagia in food deprived rats.
Although a common mechanism linking these events to AAROD is not evident, the events are consistent with previously proposed mechanisms of AAROD-associated adverse events, including electrolyte disturbance, catecholamine release, altered cardiopulmonary functioning, acute lung injury, and other physiologic effects associated with administration of high doses of opioid antagonists under general anesthesia (10).
Our results indicate that morphine exerts a dose dependent effect directly at the level of testis besides its indirect effect and this effect may be reversed by an opioid antagonist.
In previous work, it was reported that the administration of low doses of the hypothalamic opioid antagonist naloxone, facilitates the expression of oestrus in the ewe (Ovis aries), goat (Capra hircus) and sow [11-15].
The results showed a significant reduction in pruritus and "itching" during the infusion, supporting the hypothesis of an increased cerebral opioid tone in patients with liver disorders, and supporting the use of an opioid antagonist (naloxone) in infusion as a therapeutic option (2,8).
Maintenance treatment with depot opioid antagonists in subcutaneous implants: an alternative in the treatment of opioid dependence.
For these reasons, clinicians should be aware that the commonly used opioid antagonist naloxone can produce false-positive opiate immunoassay results.
So, in summary, food deprivation can induce opiate-like withdrawal; or, an opiate-like withdrawal can be obtained through the administration of the opioid antagonist naloxone.
Thus, the opioid antagonist naltrexone, but not a CRF receptor antagonist, blocked cue-induced reinstatement.
To test the possible involvement of opioid mechanism in the antinociception produced by [alpha],[beta]-amyrin or morphine, animals were simultaneously pretreated with the opioid antagonist, naloxone (2mg/kg, i.