Analgesia (Physiology and Drugs)

Question 1

NSAIDs

Answer 1

Acting at site of injury - decrease nociceptor sensitisation in inflammation.

Question 2

Local anaesthetics

Answer 2

Block nerve conduction.

Question 3

Opioids

Answer 3

Modify transmission of nociceptive signals in dorsal horn of the spinal cord.
Activating descending inhibitory controls

Question 4

Important brainstem regions in physiology of pain modulation:

Answer 4

Periaqueductal gray (PAG) - excitation by electrical stimulation produces profound analgesia.

Nucleus raphe magnus (NMR) - morphine causes excitation.

Locus coeruleus (LC) - nordadrenergic neurones

Question 5

Opioid receptors

Answer 5

mu
delta
kappa
ORL1

Question 6

mu opioid receptor

Answer 6

Most of the analgesic action

SE: respiratory depression, constipation, euphoria, sedation, dependence

Question 7

delta opioid receptor

Answer 7

Contributes to analgesia

Activation can be preconvulant

Question 8

kappa opioid receptor

Answer 8

Contributes to analgesia at spinal and peripheral level

Associated with sedation, dysphoria and hallucinations

Question 9

ORL1 opioid receptor

Answer 9

Produces anti-opioid effect