A multicenter trial of ropinirole as adjunct treatment for Parkinson's disease. Ropinirole Study Group

To evaluate the nonergot dopamine agonist ropinirole as an adjunct to L-dopa in a randomized, double-blind trial in PD patients with motor fluctuations.

L-dopa in the treatment of PD is associated with motor fluctuations, dyskinesia, and other adverse effects. The use of dopamine agonists in the treatment of PD delays recourse to L-dopa and thus delays the possibility of adverse effect onset.

Ropinirole (n = 95) or placebo (n = 54) was added to L-dopa, and L-dopa was then reduced in a planned manner during the 6-month trial.

A significantly greater number of ropinirole patients were able to achieve a 20% or greater reduction in both L-dopa dose and in percent time spent "off" compared with placebo (35.0% versus 13.0%; p = 0.003). The mean daily L-dopa dose was reduced significantly with ropinirole treatment (242 mg versus 51 mg; p < 0.001) as was the percent awake time spent "off" (11.7% versus 5.1%; p = 0.039). There was no difference in the percent of patients who withdrew because of adverse effects (15.8% on ropinirole versus 16.7% on placebo).

Ropinirole permits a reduction in L-dopa dose with enhanced clinical benefit for PD patients with motor fluctuations.