Long-term treatment with dopamine agonists in idiopathic Parkinson's disease

Long-term treatment studies with any antiparkinsonian drug are rather limited. Especially, double-blind, randomized and multicenter studies do not exist except for some rare exceptions. Nonetheless, such studies are mandatory to prove certain therapy regimens. This overview reports on the comparison between dopamine agonists and levodopa. There are open studies comparing bromocriptine, lisuride, pergolide with levodopa which demonstrate that the use of dopamine agonists in monotherapy or combination with levodopa decreases the percentage of patients who develop dyskinesias compared to levodopa only. A long-term study was performed with cabergoline (3 years) which was extended in an open trial for another 2 years and which underlined the above mentioned observation. In a very recent study, ropinirole was compared with levodopa. This double-blind study spans 5 years and shows that about 30% of patients were able to stay for 5 years on ropinirole monotherapy, that withdrawal rate was not higher in the dopamine agonist group and that the side effects were similar in the levodopa and the ropinirole group. The major finding of this study was a very low dyskinesia rate when treating patients with ropinirol alone. Thus, this study underlines our therapy concept which advocates the early use of dopamine agonists in IPS.