1 / 20

Drug presentation 1 agonist/antagonist

Drug presentation 1 agonist/antagonist. Barry Barkinsky EMS-I, Paramedic. Receptor sites. Drugs either stimulate or inhibit the cells normal biochemical actions. Receptor sites. Point of attachment for hormones, viruses, chemicals. Agonist / antagonist. Lock and key analogy.

leona
Download Presentation

Drug presentation 1 agonist/antagonist

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Drug presentation 1agonist/antagonist Barry Barkinsky EMS-I, Paramedic

  2. Receptor sites.. • Drugs either stimulate or inhibit the cells normal biochemical actions

  3. Receptor sites • Point of attachment for hormones, viruses, chemicals

  4. Agonist / antagonist

  5. Lock and key analogy • Agonist works like a lock and key that works

  6. Agonists • Bind to the receptor site and initiate the expected response • If you put the key in the lock and turn it the lock will open • Side effect

  7. Morphine sulfateclass: opioid agonist • Prototype drug: • Causes analgesia, euphoria, sedation and miosis. • Decreases preload and afterload. • May cause respiratory depression and hypotension.

  8. Morphine…mechanism • Opiate agonist • Cause the desired effect of pain relief • Also opens doors to respiratory depression and hypotension • Has successfully opened doors to: • Pain relief / High • Respiratory depression • Hypotension via vasodilation

  9. Morphine sulfate • Indications • Moderate to severe pain • Cardiac pain indicative of MI • Acute pulmonary edema • Precautions: • Hypersensitivity, undiagnosed head or abdomen injury, bronchial asthma, COPD, severe respiratory depression, pulmonary edema due to chemical agent

  10. Fentanyl (sublimaze) • potency many times that of morphine. • Schedule II drug • Also seen as duragesic or actiq • High potential for respiratory depression • Anesthetic and analgesic – dose dependant

  11. Fentanyl (sublimaze)synthetic narcotic analgesic • Indications: Induce sedation for endotracheal intubation. • Contraindications: MAO inhibitors within 14 days, myasthenia gravis. • Precautions: Increased intracranial pressure, elderly, debilitated, COPD, respiratory problems, hepatic and • renal insufficiency. • Dosage/Route: 25 to 100 mcg slowly IV (2 to 3 min). Ped: 2 mcg/kg slow IV/IM.

  12. Stadol • Name/Class: BUTORPHANOL (Stadol)/Synthetic Narcotic Analgesic • Description: Butorphanol is a centrally acting synthetic narcotic analgesic about 5 times more potent than morphine. A schedule IV narcotic. • Indications: Moderate to severe pain. • Contraindications: Hypersensitivity, head injury, or undiagnosed abdominal pain. • Precautions: May cause withdrawal in narcotic-dependent patients • Dosage/Route: 1 mg IV or 3 to 4 mg IM/3 to 4 hours.

  13. Noncompetitive antagonism • The antagonism is insurmountable • Example:You can’t effectively push CO off of hemoglobin once its got the site

  14. Competitive antagonism • Considered surmountable • Enough of an agonist can overcome the antagonism

  15. Competitive Antagonists • Bind to the site but do not cause the receptor to initiate the expected response • The key fits in the lock but will not turn and cannot open the lock – however the lock is now blocked

  16. Opioid antagonists • Reverse some of the effects of opioid drugs • Typically desired for respiratory depression effect • Shorter half life than most opioid drugs

  17. Reversal • Naloxone: opiate antagonist • Binds to opiate receptor – fits in lock but doesn’t turn it – blocks it • Doesn’t elicit the desired response: • No pain relief / No high– door blocked • No respiratory depression – door blocked • Can’t bind to the receptor causing vasodilation morphine has bound to – so hypotension is not reversed – door NOT blocked • Morphine----->>>> • Pain relief / High • Respiratory depression • Hypotension

  18. Naloxone (narcan) • Prototype opioid antagonist drug • Repeat doses may be needed to combat shorter half life • Competitively binds with opioid receptors without causing the effects of opioid binding. • Primary binding is at respiratory centers – it will not reverse hypotension

  19. narcan • Indication: • Natural of synthetic narcotic overdose • Coma of unknown origin • Precaution: shorter half life than most of the drugs it antagonizes • Dosage/Route: 0.4 to 2.0 mg IV/IM, 2 to 2.5X ET up to 10 mg, 2 mg MAD

More Related