Opioids Difference between opioid analgesic and opioid agonist?

[King J]

What is the difference between opioid analgesic and opioid agonist?

Can you combine the two?? What's the difference? Don't they both bind to their respected opioid receptors?

 

[paranoid android]

They are one and the same but with different binding properties. Morphine is a full mu receptor agonist while buprenorphine is a partial agonist as a example. You can mix full mu agonists such as morphine, hydromorphone, heroin, fentanyl, etc but you can't mix them with partial agonists like bupe or with mixed agonists/antagonists such as pentazocine.

 

[Druggist]

An analgesic is a chemical that relieves pain. An agonist is a chemical that binds to a receptor. All opiates are agonists of some kind, not all are full opiate-agonists and therefore do not necessarily cause analgesia.

 

[caseface99]

An opioid analgesic has pain killing properties, and and opioid agonist stimulates opioid receptors. But does an agonist necessarily have to cause analgesia?

 

[paranoid android]

An analgesic is a chemical that relieves pain. An agonist is a chemical that binds to a receptor. All opiates are agonists of some kind, not all are full opiate-agonists and therefore do not necessarily cause analgesia.

Well yes salvia is a good example since it's a very potent kappa receptor agonist but it is not a analgesic.

 

[Cane2theLeft]

An opioid analgesic has pain killing properties, and and opioid agonist stimulates opioid receptors. But does an agonist necessarily have to cause analgesia?

A MU agonist (whether partial or full) does necessarily produce at least some analgesia. Around here, when most people refer to full agonists they mean full MU agonists, but as PA pointed out there are other opioid receptors such as kappa that drugs like salvia agonize that don't produce analgesia.

 

[caseface99]

Thanks for the clarification.