Adjunct therapy for pain

Question 1

What is chronic orofacial pain?

Answer 1

Pain with confusing mechanisms, multifactorial due to subjective nature of pain

Can be due to teeth, gums, sinuses, TMJ, jaw and neurological problems

E.g. Post-hepatic neuralgia, where after VSV infection get trigeminal nerve pain

Question 2

What are the categories of drugs used as adjunctive therapeutic agents?

Answer 2

Antianxiety/muscle relaxant

Antidepressants

Anticonvulsants

Others

Question 3

What are antianxiety/muscle relaxants?

Answer 3

Benzodiazepines, sedatives and anxiolytics without causing analgesia

Question 4

What is one antidepressant drug?

Answer 4

Amitriptyline, from class of tricyclic antidepressants

Question 5

What does amitriptyline do?

Answer 5

Increase CNS serotonin and norepinephrine levels by blocking serotonin transporters (5HTT) and norepinephrine transporters (NET) at the pre-synaptic membrane

These transporters normally take up NE and serotonin to reduce synaptic presence

Question 6

Adverse effects of amitriptyline?

Answer 6

Tachycardia, postural hypotension, cardiac arrhythmia (can be fatal with overdose)

Dry mouth, blurring of vision, constipation and urinary retention

Sedation

Question 7

What are serotonin and NE used for in pain modulation?

Answer 7

Neurotransmitters for interneurons which moderate pain pathways, reducing pain by releasing inhibitory signals

Together with enkephalin

Question 8

What are anticonvulsants/mood stabilizers?

Answer 8

Phenytoin, carbamazepine

Increases CNS GABA, decreasing neuronal excitability by inhibiting sodium channels