opioids

Question 1

General disadvantages of opioids:

Answer 1

Disadvantages
•catabolic state
•loss of appetite
•respiratory depression , circulation anesthesia
•delayed wound healing

Question 2

Pharmacological effects of opioids in general:

Answer 2

Pharmacological effects: 
- Analgesia
•nociception , nerve fiber Ø
- Sedation
- Euphoria/dysphoria
- Cough relief
- Antidiarrheal

Question 3

Mechanism of effect of opioids:

- which receptors do they bind to?

Answer 3

Binding to endorphine receptors:
- µ opioid receptor (MOR)
- κ opioid receptor (KOR)
-

Question 4

µ opioid receptor (MOR):

• effect
• side effects

Answer 4

µ opioid receptor (MOR)
• specific , strong analgesic effect (brain , sc , periphery)
• slight sedation
• brainstem: inhibiting impulses of the respiratory centers —> respiratory depression
• antitussive
• brainstem vasomotor center —> bradycardia
• plexus myentericus —> obstipation
•medulla oblongata CTZ —> emesis

Question 5

κ opioid receptor (KOR)

Answer 5

κ opioid receptor (KOR)
•slight analgesic effect spinal cord
•slight sedation
•dysphoria

Question 6

δ opioid receptor (DOR)

Answer 6

δ opioid receptor (DOR)
• analgesia
•most important in the eye (only if damaged (1% morphine)

Question 7

Full agonists:

Answer 7

Full agonist eg:

- morphine , fentanyl , methadone on µ receptors

Question 8

Full antagonists:

Answer 8

Full antagonist : eg

-naloxone on both major receptors

Question 9

Partial agonist:

Answer 9

Partial agonist eg .

- buprenophine on µ receptors

Question 10

Agonist antagonist eg:

Answer 10

Agonist antagonist eg .

• butorphanol
• –> agonist on κ receptors
• –> antagonist on µ receptors

Question 11

General side effects opioids:

Answer 11

Side effects: 
- respiratory depression
- emesis
- bradycardia
- obstipation
- Histamine release
morphine>> fentanyl : iv:carefully !
- Hyperthermia!
- Excitation, dysphoria cats

Question 12

Drugs belonging to the opioids:

Answer 12

• Morphine:
  
  • Sedation , respiratory depression , bradycardia , emesis
  • I.V
• Fentanyl:
  
  • Short duraton of action (15 30 min)
  • Sedation, respiratory depression , bradycardia
  • IV bolus or infusion pump, transdermal patch
• Sufentanyl
• remifentanyl
• Tramadol (Rare side effects)
• Buprenorphine (very safe)
• Butorphanol

Question 13

Other sedatives:

NMDA receptor antagonist

Answer 13

• Ketamine =NMDA receptor antagonist
• Amantadine (neuropathic pain) =NMDA receptor antagonist
• Gabapentin: Tumors, neuropathic pain
  Postoperative: together with opioids