Long-term efficacy and safety of pramipexole in advanced Parkinson's disease: results from a European multicenter trial.

A double-blind, placebo-controlled study with a subsequent open-label phase was conducted in 354 patients with Parkinson's disease (PD) and motor fluctuations under individually adjusted therapy with levodopa. During the double-blind phase 174 patients received pramipexole and 180 placebo. In agreement with previous studies, pramipexole treatment improved UPDRS sum scores of parts II and III by 30% and off times by approximately 2.5 hours per day. Differences between the treatment groups became significant at a daily dose of 0.75 mg of pramipexole dihydrochloride. We, furthermore, performed post hoc analyses with respect to resting tremor and depression. Patients with pronounced resting tremor derived a clear benefit from pramipexole treatment compared with placebo. In addition, pramipexole significantly improved the subitems motivation/initiative and depression in a subpopulation with increased Unified Parkinson's Disease Rating Scale I scores at the time of inclusion. There were 262 patients who were subsequently enrolled into the open-label study featuring a maximum duration of up to 57 months. Statistical analysis revealed good long-term efficacy and tolerability of pramipexole. Overall, only a low prevalence of somnolence was found. In summary, this study provides additional level I evidence of the usefulness of pramipexole, suggests a particular tremorlytic and a possible antidepressant action of this compound, and addresses for the first time its efficacy and safety during long-term administration in advanced PD.