The isolation and naming of ergotamine by Stoll occurred in 1925 but the complete elucidation of structure was not achieved until 1951, with synthesis following some 10 years later. Current sources of ergotamine include the isolation from field ergot and fermentation broth, as well as synthesis via coupling of (+)-lysergic acid with the appropriate synthetic peptidic moiety. Ergotamine was introduced into world commerce in 1921, and is currently marketed as its water soluble tartrate salt. Ergotamine is a partial agonist at various tryptaminergic receptors (including the serotonin receptor [5-HT2]) and at various α-adrenergic receptors in blood vessels and various smooth muscles. It is likely that the major activity of ergotamine and related alkaloids is one of agonism at the 5-HT1B/1D receptors, just as with the “triptan” antimigraine compounds. FDA-labeled indications for ergotamine tartrate are in the abortion or prevention of vascular headaches, such as migraine, migraine variant, cluster headache, and histaminic cephalalgia.

Dihydroergotamine (DHE) is a semisynthetic, hydrogenated ergot alkaloid, synthesized by reducing an unsaturated bond in ergotamine. Dihydroergotamine was originally envisaged as an antihypertensive agent, but it was later shown to be highly effective in treating migraine. Dihydroergotamine was first used to treat migraine in 1945 by Horton, Peters, and Blumenthal at the Mayo Clinic. In 1986, Raskin and Callaham reconfirmed the effectiveness of DHE for both intermittent and intractable migraine. The use of DHE was reviewed by Scott in 1992. In 1997, a nasal spray version was approved for use in migraine. Dihydroergotamine is indicated for the acute treatment of migraine headaches with or without aura and the acute treatment of cluster headache episodes. Dihydroergotamine binds with high affinity to 5-HT1Dα and 5-HT1Dβ receptors. It also binds with high affinity to serotonin 5-HT1A, 5-HT2A, and 5-HT2C receptors, noradrenaline α2A, α2B and α, receptors, and dopamine D2L and D3 receptors. The therapeutic activity of dihydroergotamine in migraine is generally attributed to the agonist effect at 5-HT1D receptors. Two current theories have been proposed to explain the efficacy of 5-HT1D receptor agonists in migraine. One theory suggests that activation of 5-HT1D receptors located on intracranial blood vessels, including those on arterio-venous anastomoses, leads to vasoconstriction, which correlates with the relief of migraine headache. The alternative hypothesis suggests that activation of 5-HT1D receptors on sensory nerve endings of the trigeminal system results in the inhibition of proinflammatory neuropeptide release.

Ergoloid mesylates (USAN), co-dergocrine mesilate (BAN) or dihydroergotoxine mesylate, trade name Hydergine, is a mixture of the methanesulfonate salts of three dihydrogenated ergot alkaloids (dihydroergocristine, dihydroergocornine, and alpha- and beta-dihydroergocryptine). It was developed by Albert Hofmann (the inventor of LSD) for Sandoz (now part of Novartis). Ergoloid mesylates act centrally, decreasing vascular tone and slowing the heart rate, and acts peripherally to block alpha-receptors. One other possible mechanism is the effect of ergoloid mesylates on neuronal cell metabolism, resulting in improved oxygen uptake and cerebral metabolism, thereby normalizing depressed neurotransmitter levels. Ergoloid Mesylate may increase cerebral metabolism and blood flow. The role of this medication in the therapy of dementia is controversial. A recent controlled study in patients with Alzheimer's disease found that there was no advantage to the use of ergoloid mesylates compared to placebo, suggesting that ergoloid mesylates may lower scores on some cognitive and behavioral rating scales. Further study is needed to determine the risk-benefit profile of ergoloid mesylates in the treatment of dementia.

Ergoloid mesylates (USAN), co-dergocrine mesilate (BAN) or dihydroergotoxine mesylate, trade name Hydergine, is a mixture of the methanesulfonate salts of three dihydrogenated ergot alkaloids (dihydroergocristine, dihydroergocornine, and alpha- and beta-dihydroergocryptine). It was developed by Albert Hofmann (the inventor of LSD) for Sandoz (now part of Novartis). Ergoloid mesylates act centrally, decreasing vascular tone and slowing the heart rate, and acts peripherally to block alpha-receptors. One other possible mechanism is the effect of ergoloid mesylates on neuronal cell metabolism, resulting in improved oxygen uptake and cerebral metabolism, thereby normalizing depressed neurotransmitter levels. Ergoloid Mesylate may increase cerebral metabolism and blood flow. The role of this medication in the therapy of dementia is controversial. A recent controlled study in patients with Alzheimer's disease found that there was no advantage to the use of ergoloid mesylates compared to placebo, suggesting that ergoloid mesylates may lower scores on some cognitive and behavioral rating scales. Further study is needed to determine the risk-benefit profile of ergoloid mesylates in the treatment of dementia.