Placebo-controlled study of mesulergine in Parkinson's disease.

We used a new D2 dopamine agonist, mesulergine (8-alpha-amino-ergoline, CU 32-085), to treat 20 patients (12 men and 8 women), mean age 62.6 (SEM = 1.7) and mean duration of illness 5.9 (SEM = 1.0) years. Wearing-off effect was the principal indication for new therapy in 15 patients, and the others had inadequate response to levodopa. All continued on levodopa therapy, and 10 patients were studied in a double-blind controlled test. The mean motor disability decreased from 2.8 (SEM = 0.12) to 1.6 (SEM = 0.18) with mesulergine (p less than 0.0001) and increased to 1.9 (SEM = 0.20) with placebo (p less than 0.001). Tremor improved most, followed by rigidity, bradykinesia, gait, and postural instability. Side effects included dyskinesia, light-headedness, hallucinations, nausea, vomiting, drowsiness, and ankle edema, but, in general, mesulergine was tolerated well.