Adjunct Analgesics and Pain

Question 1

3 advantages and disadvantages of smoked cannabis

Answer 1

Advantages:
1. Pain relief
2. Improved sleep
3. Reduced anxiety
Disadvantages:
1. Not appropriate for all patients
2. Psychotropic side-effects
3. Smoking not safest mode of administration

Question 2

3 classes of cannabinoids

Answer 2

1. Phytocannabinoids (derived from cannabis plant
2. Synthetocannabinoids (man made)
3. Endocannabinoids (present naturally in the body)

Question 3

2 Cannabinoid receptors

Answer 3

1. CB1 (located on central and peripheral nerves - most common GPCR in brain)
2. CB2 (associated with immunocytes - expressed on various inflammatory cells)

Question 4

What does TRP stand for?

Answer 4

Transient Receptor Potential Channels

Question 5

TRPV1

Answer 5

The Chili Receptor
Senses capsaicin (acts on sensory nerves)
Initial sensitization and then prolonged desensitization
Expressed on C fibers and Adelta fibers
Also found in laminae I and II of spinal chord
Non-selective cation channel
Prolonged exposure/high concentration = destruction of C and Ad fibers

Question 6

Endogenous and exogenous ligands of TRPV1

Answer 6

Endogenous: Anandamide, endovanilloids
Exogenous: Capsaicin, resiniferatoxin

Question 7

TRPV1 antagonist

Answer 7

AMG517
Treats inflammatory pain
Highly potent
Selective
Oral bioavailability
Had to be removed from market due to hyperthermia

Question 8

TRPM8

Answer 8

The cool TRP
Member of the Melastatin TRP family
Non-selective cation channel
Expressed on sensory neurons
Expression increases in models of neuropathic pain
Exogenous ligands: mentol, icilin, spearmint

Question 9

Enzyme that breaks down endocannabinoids

Answer 9

FAAH

Fatty Acid Amide Hydrolase