Anti-Migrain Drugs

Question 1

common migraine

Answer 1

• no aura
• most common
• no visual or auditory warning signs

Question 2

classic migraine

Answer 2

with aura

Question 3

stages of a migraine attack

Answer 3

Prodome - before the migraine
- elation or intense energy
- depression
- craving sweets
- thirst
- irritability
- drowsiness

AURA - Stage 1
- trigger causes vasoconstriction
- some of the brain may not be getting enough oxygen due to the vasoconstriction
- this is an ischemia
- these areas are more electrically active and have cause visions or distortions
- this is called cortical spreading depression

PAIN - Stage 2
- aura disappears if there was one
- vasoconstriction becomes vasodialtion
- vasodilation associated with trigeminal N endings in walls of vessels release neuropeptides –> substance P, CGRP, neurokinin A
- these cause swelling and inflammation that send pain signals

INFLAMMATION-MUSCLE CONTRACTION - Stage 3
- pain becomes diffuse
- inflammatory signals are send to the meninges (covering the brain) - pain is between skull and brain tissue in blood vessels of the meninges
- this causes vascular inflammation and edema
- photophobia - exogenous stimuli become painful because of sensitization due to pain signal
- pain continues

POST HEADACHE - Stage 4
- relief
- fatigue

Question 4

familial hemiplegic migraine

Answer 4

• autosomal dominant subtype of migraine with aura
• point mutations in PQ type calcium channel (FMH1), Na/K ATPase pump (FMH2), Na+ channel (FMH3)
• potential increased synaptic glutamate
• aura associated with FMH1 is distinct from normal migraines

Question 5

metoclopramide

Answer 5

• agent used to prevent vomiting and nausea in migraines
• dopamine D2 antagonist
• improves gastric emptying which leads to better absorption and more rapid action of other oral drugs
• most effective when taken early in migraine

Question 6

opiates

Answer 6

• pain associated with migraine
• symptomatic relief as pain killer
• no effect on mechanism of migraine

Question 7

lidocaine

Answer 7

• targets pain associated with migraine
• local anesthetic
• nasal drops provide relief within 15 minutes
  -but hard to administer, patients have to be lying down and headaches relapse within an hour

Question 8

triptans

Answer 8

• migraine specific
• sumatriptan was first one developed to treat migrain
• agonist that binds to 5HT receptor to produce vasoconstriction and inhibit release of neurogenic peptides form trigeminal nerves
• oral, nasal, and injection
• zolmitriptan
• naratriptan
• rizatriptan

side effects
- dizziness
- nausea
- fatigue
- CV effects –> vasoconstriction

Question 9

gepants

Answer 9

• migraine specific
• newest class of treatment for migraine
• antagonist of GCRP receptor to block vasodilation
• used for acute treatment (ubrogepant)
• can be for preventative use (rimegepant)

side effects
- nausea, somnolescence, dry mouth, dizziness
- no CV effects (unlike triptans that induce vasoconstriction)