Blog#2.1

Pathology:

Migraine is a primary brain disorder most likely involving an ion channel in the aminergic brain stem nuclei (←), a form of neurovascular headache in which neural events result in dilation of blood vessels aggravating the pain and resulting in further nerve activation.

Treatment:

Ergot derivatives are highly specific for migraine pain. Ergotamine tartrate is available for oral, sublingual, rectal suppository and inhaler use. It is often combined with caffeine (100 mg caffeine for each 1 mg ergotamine tartrate) to facilitate absorption of the ergot alkaloid.

Ergot alkaloids: Here we can look at Ergotamine and Ergonovine as good examples. These drugs block alpha agonist vasoconstriction and cause a marked smooth muscle contraction. The ergot derivates have mixed partial agonist effects at 5-HT2 receptors and at alpha adrenoceptors.. The effects mentioned above helps to reduce the vasodilation which causes the migraine.

Triptans: Sumatriptan is a good example to look at here. Triptans are the first line drug therapy for acute severe migraines. Triptans should not be used in patients with coronary artery disease because they have the ability to cause coronary vasospasms. These drugs are selective agonists for 5-HT, 1D and 5-HT, 1B receptors. On the presynaptic trigeminal nerve ends they activate these receptors to inhibit the release of the vasodilating peptides. 

Beta-blockers: Not for acute attacks, but only for prophylaxis.

Anti-inflammatory analgesics: These drugs only control the pain of the migraine and don’t resolve the migraine. Aspirin is a good example.

Lasmiditan: Highly selective 5-HT 1F receptor agonist which is effective in treating migraines. This agent is much more cardiovascular safe than the triptans. This drug reduces the trigeminal nerve stimulation-induced plasma and plasma protein extravasation in dura vessels. This drug is used in acute migraines.

Calcium channel blockers: For prophylaxis only.