1.Which vascular changes can be observed before and during migraines?
Strong vasodilators cause vasodilation and oedema, which activate pain nerve endings. 

2.What is the role of serotonin in migraine headaches?
5-HT or serotonin receptors, agonists constrict the arteries which then inhibits trigeminal nerve transmission and vasoactive peptide release.

3.How is ergotamine used during a migraine attack?
Ergotamine is a partial 5-HT1 agonist which causes vasoconstriction in the intracranial arteries and inhibits trigeminal nerve transmission.

4.Which side-effects are experienced with ergotamine use? Which contra‑indications exist for using ergotamine?
Side effects include nausea, vomiting, diarrhoea, hallucinations, gangrene strong vasoconstriction, tachycardia and rebound headache. Contra-indications include cardiovascular disease, hypertension, patients suffering from liver and kidney impairment, pregnancy, and psychosis.

5.Which other drugs can be used for an acute migraine attack?  What is the action of all of these drugs?
Drugs that can be used for acute migraine attacks are Sumatriptan, Zolmitriptan, Almotriptan, Eletriptan, Naratriptan- These drugs are 5-HT1B/1D/1F agonists. They constrict the large arteries, inhibits trigeminal nerve transmission and vasoactive peptide release.

Metoclopramide-Anti-emetic, D2 antagonist at the chemoreceptor trigger zone in CNS

Cyclizine-Anti-emetic, First-generation ant-histamine, competitive antagonist at H1, muscarinic, alpha and 5-Ht receptors.

6.Name the drugs which can be used for migraine prophylaxis, as well as their specific side effects and precautions
Beta-blockers and alpha 2 agonists can be used as migraine prophylaxis. Propranolol(B-blocker) helps to stop a migraine but should not be taken during a migraine. Clonidine (alpha-2 agonist) causes vasodilation before initial vasoconstriction, but caution should be taken as it could induce a migraine attack. Calcium channel blocker-drugs could also be used such as Verapamil, Flunarizine (could prevent often attacks of migraines, Blocks H1) and Diltiazem. These drugs cause vasodilation after initial vasoconstriction. Side effects when taking Flunarizine include weight gain and depression.