Pathology of migraine 

Migraine is known to be a throbbing unilateral headache that can last for a few hours or even 1-2 days. It is characterised by an aura which can involve nausea, vomiting, visual scotomas or even hemianopsia and speech abnormalities. The headache follows. 

The trigeminal nerve distribution to intracranial arteries is involved in migraine. Peptide neurotransmitters, especially calcitonin gene-related peptide, are released by these nerves. CGRP is a powerful vasodilator. Leakage of plasma and plasma proteins into the perivascular space causes mechanical stretching which may immediately activate the pain nerve endings in the dura. 

Treatments:

5-HT1D/1B agonists, aka triptans such as sumatriptan are almost exclusively used for the treatment of migraine. These drugs activate the 5-HT1D/1B receptors which are found on the presynaptic trigeminal nerve endings in order to inhibit vasodilating peptides. This will cause vasoconstriction which may prevent the stretching of pain endings. (Used in acute severe attacks) 

Ergot alkaloids: Ergotamine and Ergonovine can be used in the treatment of migraine. These drugs act as mixed partial agonists at 5-HT₂ and alpha adrenergic receptors. When used in treatment for migraine it has a similar mechanism of action as triptans.

Beta-adrenoceptor blockers: are effective only for prophylaxis and not for the acute attack

Calcium channel blockers: Prophylaxis

Nonsteroidal anti-inflammatory analgesic agents can be used to treat the pain.