Answer and Explanation:
Ergotamine has been used for over 50 years and was the first specific drug to treat migraine attacks. Its therapeutic effect is due in part to its ability to contract the vessels. It is a vasoconstricting alkaloid used in migraine attacks, when treatment with non-steroidal anti-inflammatory drugs has no effect.
The mechanism of action of ergotamine is complex. The molecule has structural similarities to neurotransmitters such as seratonin, dopamine and adrenaline, and can therefore bind to various receptors and function as an inhibitor. Its use in the treatment of migraines is due to its vasoconstrictor effect of extracerebral intracranial blood vessels through their binding to the 5-HT1B receptor and inhibition of neurotransmitter binding.
Overuse of ergotamine may cause nausea, vomiting (to direct effects on the Central Nervous System in the vomiting centers) , malaise, headache, constriction of peripheral vessels and more severe effects such as ischemia of the extremities.
Ergotamine poisoning is called ergotism.
Ergotamine should not be used in patients with peripheral arterial or venous vascular insufficiency, ischemic heart disease, cerebrovascular disease, systemic infection and hypertension without effective control.