Anti-migraine drugs Flashcards
What is a migraine
- debilitating headache
- decreases in incidence with age
- lasts 4 - 72 hours
- two categories: 80% common migraine (without aura) and 20% classic migraine (with aura)
migraine aura
- bright dots
- flashes of light
- zigzag lines
- temp loss of vision
- blind spots
Stages of headache
- pre headache: premonitory/prodrome and AURA
2/3. headache - swelling and inflammation
- post headache: postdrome
Prodrome
before headache
- feelings of elation and intense energy
- feelings of depression
- cravings for sweets
- thirst
- irritability
- drowsiness
physiological changes with Aura
- vasoconstriction of arteries
- some of brain may experience ischemia
- cortical spreading depression: brain tissue not getting enough blood is more electrically active (wave of excitability travelling through cortex
These can occur with any headache
Physiological changes with actual headache
(pain after aura)
- vasoconstriction becomes vasodilation
- stimulation of trigeminal nerve endings in vessel walls that release neuropeptides which produce swelling and send pain signals to pain centres
- pain then becomes more diffuse
- inflammatory chemicals are released and stimulate the meninges (braincovering)
what causes vascular inflammation and edema in the brain during headache
inflammatory chemicals stimulate the meninges
FMH
familial hemiplegic migraine (FMH)
- autosomal dom subtype of migraine with distinct aura associated
point is - migraines can be genetic
vasodilatory or neurogenic theory of migraine
pain of migraine arises between skull and brain tissue in BVs of the meninges
- swollen blood vessels send pain signals to brainstem
peptides producing neurogenic inflammation
- substance P
- calcitonin gene-related peptide (CGRP)
- neurokinin A
Pathophysiology of migraine
(5 steps)
- trigeminal nerve activated
- release of peptides at BVs
- vasodilation of BVs and sterile inflammation
- signal transferred back up trigeminal
- signal goes to pain centres in brainstem and to sensory cortex
Roles of serotonin in migrianes/headaches
serotonin receptors reduce release of CGRP and substance P from trigeminal and induce vasoconstriction
migraine triggers
- coffee
- cheese
- foods containing nitrates and nitrites
- chocolate
- alcohol
- disturbed sleep pattern
- hormonal changes
- some meds: H2 blockers, nitroglycerin, estrogen contraceptives
- physical exertion
- sensory stimuli
metoclopramide
Migraine med
- blocks D2 Rs
- doesn’t affect migraine itself, relieves nausea and vomiting associated
- acts at chemoreceptor trigger zone
- improves absorption of other migraine meds (bc you’re not vomiting)
- best taken during aura
Non-specific drugs for migraines
NSAIDs (non-steroidal anti-inflamm drugs)
- ibu or aspirin
Antihistamines
- benadryl
