Fluctuating Parkinson's Disease: Treatment with the Eong-Acting Dopamine Agonist Cabergoline

Assessment of the very long-acting dopamine agonist medication cabergoline in the control of motor fluctuations in Parkinson's disease. Open-label trial (13 weeks). Referral centers (Mayo Clinic, Rochester, Minn, and Scottsdale, Ariz). Volunteer sample of 41 patients with idiopathic Parkinson's disease who were experiencing motor fluctuations while receiving stable doses of carbidopa and levodopa. Adjunctive oral cabergoline was incrementally administered once daily with the maintenance dose determined by the clinical response (maximum dose, 5 mg/d). Standardized serial motor examinations were performed, beginning anywhere from 30 minutes before and continuing to 6 hours after test doses of medications were administered. Scores during adjunctive cabergoline therapy were compared with the prestudy baseline scores during therapy with carbidopa and levodopa without cabergoline. Adjunctive cabergoline therapy significantly improved mean motor scores at the time of each standardized serial examination, from 30 minutes to 6 hours after the administration of test doses of medications. Significant motor score improvement was also measured 24 hours after the last cabergoline dose was administered, suggesting a very long-acting antiparkinsonian effect. Mean dyskinesia scores were slightly but nonsignificantly elevated. Diary card “off-time” was improved by 42%, whereas the levodopa dosage was reduced by 18%. Only three patients dropped out (7% of the total), which contrasts with much higher dropout rates owing to adverse events in previous clinical trials of other antiparkinsonian dopamine agonists. Cabergoline improved motor control in patients with Parkinson's disease who were experiencing clinical fluctuations. Possible advantages of this medication include an extended clinical response (persisting to 24 hours), tolerability, and ease of use (once per day administration).