SYNOPSISDependence upon a variety of drugs ‐ ergotamine, analgesics, benzodiazepines, corticosteroids ‐is a major reason for patients to enter an intractable phase of their migrainous disorders. Repeated dosing of dihydroergotamine has proven to be remarkably effective in stabilizing the mechanism of migraine, allowing these patients to make the transition to a more reasonable as well as more specific form of ther