Analgesic Drugs

Question 1

Nociception

Answer 1

Detection of noxious stimuli or stimuli capable of damaging tissue

Question 2

4 Processes of pain

Answer 2

Transduction
Transmission
Perception
Modulation

Question 3

Neuropathic pain

Answer 3

Defined as “pain induced by injury to or disease of the somatosensory system”

Nerve injury or infections of nervous system

Question 4

Analgesic

Answer 4

Selectively blocks the sensation of pain without blocking other symptoms or loss of consciousness

Question 5

Anesthetic

Answer 5

Local anaesthetic blocks nerve conduction and all local sensations (including pain)

General anaesthetics cause loss of sensations and unconsciousness

Question 6

Site of action of opioids

Answer 6

1. higher centres to alter the psychological response to pain
   ●pain can still be felt but produces less suffering
   (Perception)
2. reduce neurotransmitter release from terminals pain fibres in dorsal horn of spinal cord (modulation)

Question 7

Opioids

Answer 7

Acts on opioid receptors

All opioid analgesics are full agonists or partial agonists at µ and k receptors

Properties of different opioid drugs result from variations in
●pharmacokinetics
●affinity and activation for different opioid receptor subtypes

Question 8

Opioid Receptor

Answer 8

µ (mu) receptors
●Analgesia
●Brain (cortex, medulla, thalamus, limbic system, amygdala) and spinal cord

Kappa Receptors
•Analgesia
•Brain and spinal cord
•Dysphoria and hallucinations

Question 9

Morphine

Answer 9

Acute and chronic pain

Acts on mu (m) opioid receptors in brain/spinal cord

Question 10

Analgesics for cancer pain

Answer 10

NSAIDS (most common non-narcotic analgesic)

Adjuvants (antidepressant, anti seizure drugs, glucocorticoids

Question 11

Naloxone

Answer 11

Opioid antagonist

shorter half life (2h) than morphine