Objectives: To compare the safety and efficacy of ropinirole and bromocriptine as adjunct therapy in patients with Parkinson's disease (PD) not optimally controlled by L-dopa.
Methods: A randomised, double-blind trial in which 555 patients were assigned to three treatment groups according to the level of daily dosage of L-dopa, presence of motor fluctuations, and use of dopamine agonist before study entry. Patient response was defined as at least a 20% reduction in daily L-dopa dose plus: for patients with no prior treatment and no motor fluctuations, a 20% reduction in UPDRS motor score; for patients with motor fluctuations, a 20% reduction in time spent "off"; and for patients already taking an agonist, an improvement on the CGI scale.
Results: Safety assessments showed no significant differences in the two treatment groups for patients without prior dopamine-agonist therapy. In the group of patients with prior dopamine-agonist therapy, more patients reported adverse events in the ropinirole group (90% versus 79%, p < 0.001). The proportions of responders tended to be higher in ropinirole groups compared with bromocriptine groups and, in the subgroup with motor fluctuations, this difference was statistically significant (9.1% versus 0.0%, respectively; p < 0.05).
Conclusions: Both drugs were well tolerated. In patients receiving a relatively high dose of L-dopa and requiring the addition of a dopamine agonist to control motor fluctuations or dyskinesias, ropinirole was significantly more effective than bromocriptine.