Dihydroergotamine (DHE), sold under the brand names D.H.E. 45 and Migranal among others, 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 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. Medical uses
Subcutaneous and intramuscular injections are generally more effective than the nasal spray and can be self-administered by patients. Intravenous injection is considered very effective for severe migraine or status migrainosus. DHE is also used in the treatment of medication overuse headache. Side effects
Nausea is a common side effect of IV administration and less common in other modes. Antiemetics can be given prior to DHE to counteract the nausea. Risks and contraindications are similar to the triptans. DHE and triptans should never be taken within 24 hours of each other due to the potential for coronary artery vasospasm. DHE produces no dependence. Contraindications
DHE is contraindicated with potent CYP3A4 inhibitors, like macrolide antibiotics. Pharmacology
Mechanism of action
DHEs antimigraine activity is due to its action as an agonist at the serotonin 5-HT1B, 5-HT1D, and 5-HT1F receptors. It also interacts with other serotonin, adrenergic, and dopamine receptors.DHE is an agonist of the serotonin 5-HT2B receptor and has been associated with cardiac valvulopathy.
Stage 4: Progressive loss of consciousness into a persistent vegetative state, which may be preceded by or concomitant with paralysis, occurs in the final stage, during which breathing, heart rate, and blood pressure are affected. Death usually occurs as a result of fever, heart failure, or the brain’s inability to control the autonomic nervous system. Pathogenesis
A large number of nucleocapsids are produced in the neurons and the glial cells. In these cells the viral genes that encode envelope proteins have restricted expression. As a result, infectious particles like the M protein are not produced, and the virus is able to survive persistently without evoking an immune response. Eventually the infection will lead to SSPE. Diagnosis
According to the Merck Manual: "SSPE is suspected in young patients with dementia and neuromuscular irritability. EEG, CT or MRI, CSF examination, and measles serologic testing are done. EEG shows periodic complexes with high-voltage diphasic waves occurring synchronously throughout the recording. CT or MRI may show cortical atrophy or white matter lesions. CSF examination usually reveals normal pressure, cell count, and total protein content; however, CSF globulin is almost always elevated, constituting up to 20 to 60% of CSF protein. Serum and CSF contain elevated levels of measles virus antibodies. Anti-measles IgG appears to increase as the disease progresses. If test results are inconclusive, brain biopsy may be needed."