Migraines Flashcards
What are the three divisions of the trigeminal nerve?
Ophthalamic, maxillary, mandibular.
What are the 3 purposes of the trigeminal system?
- Senses pain and temperature in head.
- Innervates dura mater.
- Controls cerebral blood vessels.
What is the mechanism of a migraine?
Not completely known, but pain in head is detected by the ophthalamic branch innervating the dura mater, associated with the vessels. Vessels dilate during attack causing inflammatory ‘painful’ response.
How does serotonin alleviate migraines?
5-HT leads to vasoconstriction.
What is CGRP?
Calcitonin gene-related peptide located in trigeminal nerve afferents. Released in response to pain to cause vasodilation. Gi-coupled.
What are the two treatment strategies for migraines?
- Prophylactic.
2. Abortive.
What are pharmacological prophylactics?
Drugs that decrease blood pressure, excitability of brain, and SSRIs. All preventative drugs taken daily.
What are abortive pharmacological drugs?
Non-specific analgesics.
How does caffeine alleviate migraines?
Adenosine receptor antagonist, leads to vasoconstriction and increases absorption of NSAIDs.
What are ergotamines?
Ergot alkaloids that are agonists for 5HT-1b/d receptors that inhibit neurogenic inflammation. Have a low degree of receptor selectivity.
What is the coronary effect of ergotamines?
May produce coronary vasoconstriction due to lack of selectivity of 5HT receptors.
What is the bioavailability of ergotamines? Why is it this number?
<1% due to karge first pass metabolism.
How are ergotamines excreted?
In bile.
What are triptans?
First line migraine abortant drugs, selective 5-HT1b/d agonist.
What are the two mechanisms of triptans?
Vasoconstriction and inhibition of the trigeminal nerve.
