Double-blind comparison of cabergoline and bromocriptine in Parkinson's disease patients with motor fluctuations.
In the present study we compared the efficacy and safety of the new dopamine agonist cabergoline (CBG) with bromocriptine (BCR) in Parkinson's disease (PD). CBG has a very long half-life and can be administered as a single daily dose. Forty-four PD patients with uncontrolled motor fluctuations participated in the study. Patients were randomly and blindly assigned to equivalent doses of either CBG or BCR in addition to preexisting levodopa. Dosage was titrated to optimal, using up to 6 mg of CBG or 40 mg of BCR daily. CBG was given as a single morning dose whereas BCR was administered tid. Sixteen patients were followed for 1 year and 16 additional patients for 6 months. The mean follow-up duration was 9 +/- 5 months. The main effect of both drugs was observed on motor UPDRS scores, rigidity, bradykinesia items, and the percentage of awake hours spent during "on" and "off". In general, the effect of CBG was similar to that of BCR. The percentage of awake hours spent during "on" was higher with CBG as compared with BCR. Adverse events included dyskinesias, orthostatism, confusion, edema, and paresthesias in limbs. These effects were seen at similar frequencies with both drugs. The study shows that CBG given as a single morning dose is at least as efficacious as BCR given tid. CBG is a promising dopamine agonist for the treatment of motor fluctuations in PD.
Cabergoline produces similar benefits to bromocriptine in off time reduction, motor impairment and disability ratings, and levodopa dose reduction over the first three months of therapy. Dyskinesia and confusion were increased with cabergoline but otherwise the frequency of adverse events and withdrawals from treatment were similar with the two agonists.