PHARM Pain, Opioids & Other Analgesics

Question 1

What receptors do opioids act and are they antagonists/agonists?

Answer 1

m-, d-, k-
Agonists.

Question 2

What opioid acts as an antagonist?

Answer 2

Naloxone.

Question 3

What does m- receptor activation cause?

Answer 3

u receptor activation – causes activation of K+ current via K+ channels resulting in hyperpolarisation & reduction of Ca2+ in current by inhibition of Ca2+ channels.
Prevents release of ACh from cholinergic nerves.

Question 4

What NTs may be activated by descending pathways which are involved in the production of an analgesic effect?

Answer 4

NA & 5HT.

Question 5

Loperamide function

Answer 5

Anti-diarrhoeal due to poor absorption in GIT.

Question 6

Tramadol function

Answer 6

Causes release of NA & 5HT.

Question 7

Classify tramadol as a weak/strong opioid.

Answer 7

Weak.

Question 8

Classify codeine as a weak/strong opioid.

Answer 8

Weak.

Question 9

Classify fentanyl as a weak/strong opioid.

Answer 9

Strong.

Question 10

Classify morphine as a weak/strong opioid.

Answer 10

Strong.

Question 11

Classify pethidine as a weak/strong opioid.

Answer 11

Strong.

Question 12

Classify oxycodone as a weak/strong opioid.

Answer 12

Strong.