Dihydroergotamine (DHE)

Dihydroergotamine is an ergot alkaloid used to treat migraines. It is a derivative of ergotamine. It is administered as a nasal spray or injection and has an efficacy similar to that of sumatriptan. Nausea is a common side effect. It has similar actions to the triptans, acting as an agonist to the serotonin 5-HT(1D) receptors and causing vasoconstriction of the intracranial blood vessels, but also interacts centrally with dopamine and adrenergic receptors. It can be used to treat acute intractable headache or withdrawal from analgesics. DHE is available as Migranal nasal spray and in ampules for subcutaneous, intramuscular and intravenous injection. Efficacy is variable in the nasal spray form with bioavailability 32% of injectable administration. Subcutaneous and intramuscular injections are generally more effective than the nasal spray and can be self-administered by patients.