A PLACEBO-CONTROLLED EVALUATION OF ROPINIROLE, A NOVEL D-2 AGONIST, AS SOLE DOPAMINERGIC THERAPY IN PARKINSONS-DISEASE

The efficacy and safety of ropinirole, a novel nonergot dopamine D-2-l ike receptor agonist, was assessed as monotherapy for the treatment of patients with early-stage Parkinson's disease. In this double-blind, multicenter trial, patients were randomly allocated in a ratio of 2:1 to receive, over a 12-week period, either ropinirole or placebo. Clini cal status was assessed using the Unified Parkinson's Disease Rating S cale (UPDRS), Clinician's Global Evaluation (CGE), and a finger-tappin g score. In all, 41 patients received ropinirole and 22 received place bo. The end-point analysis, on an intention-to-treat basis, revealed a significant difference (p = 0.018) in improvement in UPDRS motor scor e from baseline between treatment groups (ropinirole, 43.4%; and place bo, 21.0%). Other parameters, including the number of responders and i mprovement in CGE, showed similar results. Three patients in the ropin irole group and one patient in the placebo group discontinued the stud y because of adverse events. There was no significant difference betwe en the treatment groups in the overall incidence of adverse events. Al though the dopaminergic side effects were reported significantly more frequently in the ropinirole group than in the placebo group (dizzines s, p = 0.0326; nausea, p = 0.001; and somnolence, p = 0.005), none nec essitated study withdrawal. There was no evidence of any chronic effec t of the study medication on vital signs. In conclusion, ropinirole is a safe and well-tolerated drug and, as monotherapy, provided signific ant therapeutic benefit compared with placebo to patients in the early stages of Parkinson's disease.