Dihydroergotamine mesylate is a partial agonist for both dopaminergic and α-adrenergic receptors. Dihydroergotamine mesylate also acts as a full agonist for the 5-HT receptor, with IC50 values being 2 nM and 2.2 nM for human 5-HT1B and 5-HT1D receptors stably expressed in HEK 293 cells and C6 glioma cells, respectively. Like other potent 5-HT receptor agonists such as sumatriptan, dihydroergotamine mesylate has been approved for acute migraine therapy.
References:
1. Lesage AS, Wouters R, Van Gompel P, et al. Agonistic properties of alniditan, sumatriptan and dihydroergotamine on human 5-HT1B and 5-HT1D receptors expressed in various mammalian cell lines. British Journal of Pharmacology, 1998, 123(8): 1655-1665.
2. Schaerlinger B, Hickel P, Etienne N, et al. Agonist actions of dihydroergotamine at 5-HT2B and 5-HT2C receptors and their possible relevance to antimigraine efficacy. British Journal of Pharmacology, 2003, 140(2): 277-284.
3. Villalón CM, Bom AH, Den Boer MO, et al. Effects of S9977 and dihydroergotamine in an animal experimental model for migraine. Pharmacological Research, 1992, 25(2): 125-137.