Migraine

Question 1

Features of a migraine

Answer 1

• duration (4-72 hours)
• Pulsating, more less unilateral
• moderate to severe pain
• impair function
• nausea/vomiting more less photo/photophobia

Question 2

Consistently two major issues

Answer 2

• Vascular

- Neurogenic

Question 3

Vascular theory on migraines

Answer 3

• begins with vasoconstriction of cerebral vessels
• the subsequent reduction in blood flow causes the ‘aura’
• then there is a compensatory dilation of vessels, which leads to pain

Question 4

Neurogenic theory on migraines

Answer 4

• attacks precipitated by excess excitation in neocortex
• followed by ‘cortical spreading depression’ (CSD): rapid and profound depolarization of neurons
• this CSD leads to the aura and this triggers the pain

Question 5

Pharmacology of migraines

Answer 5

• dilation/inflammation of cerebral vessels
• release of pain mediators
• serotonin seems to play a role in both

Question 6

Treatment of migraines

Answer 6

Triptans

Ergots

Question 7

Sumatriptan mechanism

Answer 7

Agonist at 5HT-1B and 5HT-1D
Vasoconstrictor
Reduced release of pain transmitters

Question 8

Sumatriptan pharmacokinetics and ROA

Answer 8

Onset varies depending on route 
Routes of administration
- Oral
- Nasal spray
- Subcutaneous

Question 9

Triptans side effects related to vasoconstriction

Answer 9

Related to vasoconstriction 
- chest/neck discomfort 
Rare, serious:
- myocardial ischemia/infarction
- Avoid in patients with cardio-/cerebrovasscular disease

Question 10

Triptans side effects due to serotonin

Answer 10

Nausea

Caution: serotonin syndrome

Question 11

Ergot alkaloids example

Answer 11

Dihydroergotamine

Question 12

Dihydroergotamine mechanism

Answer 12

Agonist at 5HT-1B, 5HT-1D, and alpha 1

• vasoconstrictor
• reduced release of pain mediators

Question 13

Route of administration of ergot alkaloids

Answer 13

Injectable

Nasal Spray

Question 14

Acute Migraine treatment

Answer 14

Anti-inflammatory: NSAIDs
Acetaminophen 
Opioids
- codeine containing products
- Butorphanol

Question 15

Opioids in migraine

Answer 15

• not addressing main issues, no vasoconstriction effects, no anti-inflammatory effects
• tolerance/withdrawal/dependence

Question 16

Butorphanol mechanism

Answer 16

• partial agonist/mixed agonist-antagonist at opioid receptors
• more likely to see dysphoria
• kappa agonist

Question 17

Butorphanol route of administration

Answer 17

Nasal spray

- definite potential for dependence

Question 18

Medication overuse headache

Answer 18

Frequent headaches (>15/month)
- Can occur with any drugs for migraine: some drugs are higher risk than others

Question 19

MOH mechanism

Answer 19

• unknown
• effects of chronic drug use for headache: changes in neurotransmitter levels, decreases threshold for developing a subsequent headaches

Question 20

MOH management

Answer 20

• discontinue headache medication

- switch to prophylaxis

Question 21

Migraine prophylaxis

Answer 21

Reuptake inhibitors (tricyclic antidepressants)
Na+ channel blockers (Valproic Acid) 
Calcium alpha 2 delta channel blockers (Gabapentin)

Question 22

Pain mechanism

Answer 22

• Increase number of Na+ channels
• Facilitates propagation of action potentials (noxious stimuli no longer necessary
• Calcium channel opens
• prompts release of pain mediators

Question 23

Beta blockers for migraine

Answer 23

Propranolol

Question 24

Beta blockers mechanism

Answer 24

Inhibit SNS activity - may modulate hyperexcitability

Some beta blockers may also modulate 5HT: off target effects

Question 25

Calcium channel blocker for migraines

Answer 25

Verapamil