Aa
A
A
Close
466909 tn?1207571832
Still learning. I found this of use and wanted to share
Q:      What's the difference between an opiate agonist and an opiate antagonist?

A: An agonist is an agent that binds to a receptor and activates that receptor in order to elicit an effect (typically transmitting a signal to the inside of the cell, either by opening a channel to allow ions to flow in/out, or changing the receptor's shape to cause a cascade of intracellular events to occur). Drugs that are agonists essentially mimic the action of the endogenous (naturally occuring) neurotransmitters, typically with the same or a stronger affinity than the neurotransmitter itself.

An antagonist is an agent that binds to a receptor but does not elicit the response that the neurotransmitter or an agonist would cause. The antagonist blocks the receptor and prevents activation by neurotransmitters or other drugs.

So in the case of opiates, lets look at the opiate agonist Morphine. When Morphine enters the brain, it binds to opioid receptors and activates them. This binding is what produces the effects of Morphine.

In the case of a Morphine overdose, where a hospital is concerned that the high dose of Morphine may be dangerous (depressing breathing and heartrate), they may administer Naloxone (an opiate antagonist). The Naloxone finds its way to your opiate receptors and "competes" with Morphine for binding of the receptors. Because Naloxone has a higher affinity for the receptors than Morphine, the Naloxone will generally win out, replacing much of the Morphine at the receptor sites.

Within 1-3 minutes of a sufficient Naloxone injection (2-4 mg), a patient who has OD'd on Morphine will generally wake up, usually quite agitated. If given to an otherwise "normal" person (not in the midst of an overdose) who happens to be addicted to an opioid or opiate, Naloxone can immediately precipitate withdrawl symptoms (nausea, vomiting, disorientation, halluncinations, excretion, tremors, convulsions, agitation, anxiety, etc).
Cancel
2 Answers
Page 1 of 1
Avatar universal
That is exactly why addicts should avoid Talwin (pentazocaine) - after it started being abused on the streets the Company added narcane to the formulary. An addict taking Talwin will be tossed immediately (almost) into nasty precipitated withdrawal. Trust me, I've been there. And if you are od'd on methadone the first thing the EMT's do is suspect a narcotic overdose and inject narcane (the antagonist) - this can lead to strong enough shock to induce respiratory arrest....again, trust me - this is from personal experience.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
I read where Narcan will induce w/d severe within minutes.. I worked EMS years ago and we pushed it on a Vietnam Vet that had OD on SINEQUAN (doxepin HCl).. that was one medication it would not reverse  but we had nothing to lose. Dr orders fron ER.. . We were 15min out from ER.. He died later that morn.. We ran the call right at shift change at 7am.. That was tough to take..
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Submit Comment
Your Answer
Avatar universal
Answer
Know how to answer? Tap here to leave your answer...
Answer
Submit Answer
A
A
Blank
Weight Tracker
Weight Tracker
Start Tracking Now
Addiction: Substance Abuse Community Resources
RSS Expert Activity
233488 tn?1310696703
Blank
Marathon Running Done Over Many Yea...
05/15 by John C Hagan III, MD, FACS, FAAOBlank
233488 tn?1310696703
Blank
New Article on Multifocal IOL vs &q...
05/15 by John C Hagan III, MD, FACS, FAAOBlank
748543 tn?1463449675
Blank
TMJ/TMJ The Connection Between Teet...
01/15 by Hamidreza Nassery , DMD, FICOI, FAGD, FICCMOBlank
Top Addiction Answerers
Avatar universal
Blank
phoenix, AZ
406584 tn?1399591666
Blank
495284 tn?1333897642
Blank
City of Dominatrix, MN
4522800 tn?1459192030
Blank
7163794 tn?1457370413
Blank
New Orleans, LA
Avatar universal
Blank
los angeles, CA