Long-term effects of cabergoline and levodopa in Japanese patients with early Parkinson's disease: a 5-year prospective study

Several international studies have suggested that treatment of early Parkinson's disease (PD) with a dopamine agonist instead of levodopa delays the occurrence of motor complications. This 5-year prospective, open, multicenter randomized study aimed to compare the effects of cabergoline on the onset of motor complications with those of levodopa in Japanese patients with early PD. Patients who had never been treated with dopamine agonists or levodopa were enrolled in this study. Four of 45 patients in the cabergoline group and 11 of 46 patients in the levodopa group developed motor complications. The estimated cumulative incidence of motor complications in the cabergoline and levodopa groups was 17% and 34% (hazard ratio, 0.57;95% confidence interval, 0.18-1.81; p = 0.347). Thirty-five adverse events (AEs) were reported in 24 patients in the cabergoline group, while 16 AEs were reported in 13 patients in the levodopa group. Patients in the cabergoline group showed fewer motor complications than did those in the levodopa group, although the difference was not statistically significant. However, the hazard ratio found in this study was similar to those in previous reports.