Agonists and Antagonists

What exactly is the difference between Agonist and Antagonist?

An agonist is a drug that binds to and activates a receptor to mimic the activity of a signal ligand. An antagonist, on the other hand, is a medicine that binds to a receptor without activating it, but reduces the receptor’s ability to be triggered by other agonists.

Agonist

An agonist is a drug that stimulates certain brain receptors. Full agonist opioids completely activate the opioid receptors in the brain, producing the full opioid impact.

Antagonists

Antagonist is the opposite of agonist. An antagonist is a drug that binds to the receptor either at the main location or at another site, preventing the receptor from responding. Antagonist is the polar opposite of agonist. Opioid antagonists prevent opioids from acting in the brain.

Full and partial agonists:

  1. Alfentanil
  2. Buprenorphine
  3. Butorphanol
  4. Codeine
  5. Diphenoxylate
  6. Fentanyl
  7. Heroin
  8. Hydrocodone
  9. Hydromorphone
  10. Levorphanol
  11. Loperamide
  12. Meperidine
  13. Methadone
  14. Morphine
  15. Opium
  16. Oxycodone
  17. Oxymorphone
  18. Pentazocine
  19. Remifentanil
  20. Sufentanil
  21. Tramadol

Opiate antagonists

  1. Naldemedine
  2. Nalmefene
  3. Naloxegol
  4. Naloxone
  5. Naltrexone