Methysergide in the treatment of narcolepsy.

Five patients with narcolepsy (four with the allied symptom of cataplexy) were treated with the serotonin antagonist methysergide. All patients had as good control of their sleep attacks while on methysergide therapy as on a control period of dextroamphetamine therapy. The cataplexy was less well controlled by methysergide than by dextroamphetamine, but improved when compared to a period without medication. Two patients developed severe calf claudication while on methysergide.