Pain Management 3

  1. What is mechanism of action for opioids?
    • Act at pre and post synaptic receptors
    • present in the peripheral and central nervous systems
  2. What are the different types of opioid receptors?
    • OP1 - delta
    • OP2 - kappa
    • OP3 - mu
    • sigma
  3. Where is the delta receptor located?  What does stimulstion of this receptor result in?
    • Located in the limbic system of the brain
    • stimulation results in analgesia and modulation of mu receptors
  4. Where is te kappa receptor located and what does stimulation of this receptor result in?
    • Located in cerebral cortex and spinal cord
    • stimulation results in spinal analgesia, mild sedation, diuresis, and miosis
  5. Where is the mu receptor located and what does stimulation of this receptor result in?
    • Located throughout the brain and in the dorsal horn of the spinal cord
    • stimulation results in profound analgesia, euphoria, sedation, miosis, respiratory depression, chemical dependence, inhibition of GI motility, ADH release, can cause panting in dogs
  6. What does stimulation if the sigma receptor result in?
    • Dysphoria
    • hallucinations
  7. What do sigma receptors do?
    Sigma receptors bind to opioid and several non-opioid drugs and have no affinity for the opioid reverser agent naloxone
  8. What are the side effects and contraindications for opioids?
    • Decreased heart rate 
    • vomiting
    • dysphoria in cats (reduce dose, give tranquilizer)
    • contraindicated in patients with suspected intracranial hypertension
  9. Synergistic analgesic effects with...
    • phenothiazines
    • alpha 2 agonists
    • NSAIDs
    • benzodiazepines
    • local analgesics
  10. What are the two categories for deciding which opioids to use?
    • mild to moderate pain
    • moderate to severe pain
  11. Which opioids can we use for mild to moderate pain?
    • fentanyl patch (Duragesic)
    • codeine
    • butorphanol (Torbugesic)
    • buprenorphine (Buprenex)
  12. Which opioids can we use for moderate to severe pain?
    • morphine
    • tramadol
    • oxymorphone (Numorphan)
    • hydromorphone (Dilaudid)
  13. What are some opioid antagonists?
    • naloxone hydrochloride (Narcan)
    • levallorphan tartrate (Lorfan)
    • nalorphine hydrochloride (Nalline)
  14. What receptors does butorphanol affect?
    • mu antagonist
    • kappa agonist
  15. Which receptors does buprenorphine affect?
    partial mu agonist
  16. Which receptors does morphine affect?
    mu agonist
  17. Which receptors does tramadol affect?
    partial mu agonist
  18. Which receptors does naloxone affect?
    pure antagonist
  19. Which receptors does levallorphan tartrate affect?
    mixed agonist - antagonist
  20. Which receptors does nalorphine hydrochloride affect?
    mixed agonist - antagonist
  21. What is the mechanism of action for local analgesics?
    prevent conduction of nerve impulses by inhibiting passage of Na through nerve cell axon membranes
  22. What are the side effects and contraindications for local analgesics?
    excessive overdoses or accidental IV injection can cause CNS toxicity (seizures) and cardiovascular toxicity
  23. What happens when we give local analgesics with general anesthetics?
    reduces the dose of general anesthetics needed
  24. What are some local analgesics?
    • lidocaine (Xylocaine)
    • bupivacaine (Marcaine)
    • mepivacaine (Carbocaine)
  25. What is the mechanism of action for alpha 2 agonists?
    • activation of alpha 2 receptors
    • cause the neurons to become unresponsive to excitatory input
    • inhibits release of norepinephrine
  26. What are the side effects and contraindications of alpha 2 agonists?
    • can cause severe bradycardia
    • avoid in patients with cardiac problems
    • vomiting may occur, especially in cats
  27. What are alpha 2 agonists synergistic with?
    • opioids
    • and many general anesthetic drugs
  28. What are some alpha 2 agonists?
    • xylazine (Rompun)
    • medetomidien (Domitor)
    • detomidine (Dormosedan)
  29. What are some alpha 2 antagonists?  And what do they reverse?
    • yohimbine (Yobine) - reverses xylazine
    • atipamezole (Antisedan) - reverses medetomidine
  30. What is the mechanism of action for NSAIDs?
    • inhibit COX (cyclooxygenase)
    • older NSAIDs are general COX blockers and also block protective GI and renal prostaglandins
    • newer NSAIDs more specifically block COX-2 and inflammatory prostaglandins that sensitize peripheral nociceptors
  31. What are the side effects, contraindications, and toxicities of using NSAIDs?
    • use cautiously in cats
    • monitor long term use with lab work and use lowest effective dose
    • use cautiously in bleeding disorders or close to surgery time (reduces platelet function)
    • use cautiously in patients with GI bleeding or renal disease (may suppress good prostaglandins)
  32. When are renal prostaglandins released?
    under low renal blood flow conditions to cause renal vasodilation
  33. What can NSAIDs enhance in the GI and renal?
    toxicity of corticosteroids
  34. What are some examples of NSAIDs?
    • carprofen (Rimadyl)
    • aspirin
    • etodolac (Etogesic)
    • meloxicam (Metacam)
    • phenylbutazone
    • ketoprofen (Ketofen, Orudis, Anafen)
    • robenacoxib (Onsior)
    • flunixin meglumine (Banamine)
    • meclofenamic acid (Arquel)
    • tolfenamic acid
    • acetaminophen (Tylenol)
  35. Which NSAIDs are approved in cats?
    • robenacoxib
    • meloxicam
  36. Which NSAIDs are hard on dog and cat GI systems?
    flunixin meglumine
  37. Which NSAIDs are toxic to cats?
  38. What is the mechanism of action for analgesic adjuvant agents?
    • have primary medical indications other than pain
    • enhance analgesia by interacting with a variety of receptors or interfering with nerve conduction
  39. Which drugs should we avoid using with analgesic adjuvant agents?
    avoid combining NSAIDs and corticosteroids in the patient - increased risk of GI ulcers and nephrotoxicity
  40. What are some analgesic adjuvant agents?
    • ketamine
    • phenothiazine (acepromazine)
    • benzodiazepine (diazepam)
    • corticosteroid (prednisolone)
    • tricyclic antidepressant (amitriptlyine)
    • anticonvulsant (phenytoin)
    • antiarrhythmic (mexilitine)
    • beta-adrenergic blocker (propranolol)
  41. What is a transdermal analgesic?
    fentanyl patch
  42. How do we administer a transdermal analgesic?
    • place firmly on a clipped region
    • cover with a bandage
    • apply 12 - 24 hours before surgery
    • use other opioids as needed to supplement
  43. What are some non-pharmacologic methods of pain control?
    • nutraceuticals (Cosequin)
    • physical rehab techniques - massage, therapeutic ultrasound, hydrotherapy, exercise, homeopathy, chiropractics, acupuncture, laser therapy
Card Set
Pain Management 3
Clinical Practice ll