CPTP 3.21 Opioids

Question 1

Describe mu receptors

• where it mediates analgesic effects
• effect on respiration
• dependence/aversion

Answer 1

• mediates analgesia in brain
• respi depression
• dependence

Question 2

Describe kappa receptors

• where it mediates analgesic effects
• effect on respiration
• dependence/aversion

Answer 2

• mediates analgesia in spinal cord
• respi stimulation
• dependence

Question 3

Describe delta receptors

• where it mediates analgesic effects
• effect on respiration
• dependence/aversion

Answer 3

• mediates analgesia in CNS & elsewhere
• no effect on respi rate
• aversion (due to nausea, feeling ill)

Note: delta receptors interact with enkephalins

Question 4

Effect of opioid agonists on neurotransmission

Answer 4

• inhibition of GABA release (disinhibition)
• increased VTA neurone activity
• increased release in nucleus acuumbens

Question 5

Which of the opioid agonists has the longest half life? Clinical use?

Answer 5

Methadone

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