Early combination of bromocriptine and levodopa in Parkinson's disease: a prospective randomized study of two parallel groups over a total follow-up period of 44 months including an initial 8-month double-blind stage.

To determine if the combination of levodopa (LD) plus bromocriptine (Br) in the early stages of Parkinson's disease (PD) permits reduction of LD dosage and consequently results in fewer motor fluctuations and dyskinesias, a double-blind, multicenter prospective study in 50 PD patients who had responded favorably to LD while under treatment with that drug for < or = 6 months was undertaken. Patients were randomized into two parallel groups (LD alone and LD plus Br). During the first placebo-controlled stage of the study lasting 8 months, association of a fixed dose of Br (15 mg/day) in the LD regimen did not allow a significant reduction in the daily LD dose. Still, in patients on combined LD plus Br, there was a tendency toward smaller daily requirements of LD as compared with those on LD alone, and the difference in LD dose between the two groups was significantly different (515.4 +/- 240 vs. 725.6 +/- 230 mg/day; p < 0.01) after 44 months of continuous treatment in the 40 patients still enrolled in the open-label stage. At that point in time, the mean dose of Br had been increased by 9.2 mg in the combined treatment group, and the mean dose of LD was 40.7% lower than in the group receiving LD alone. On subsequent evaluations, the number of patients with dyskinesias or describing wearing-off fluctuations severe enough to require changes in treatment was lower than in the group under combined therapy, the differences being significant after 20 and 44 months, respectively (36.8 vs. 9.5 and 47.3 vs. 14.2%). Our results support early combined LD-Br therapy in PD, but no conclusions can be drawn as to whether this dopamine agonist exerts a preventive effect on the late side effects of LD or has another mechanism of action.

Low-dose bromocriptine in the early phases of Parkinson's disease.

The effect of bromocriptine at doses up to 20 mg/day was studied in a single-blind format with a placebo phase in 15 Parkinson's disease patients with mild-to-moderate disability who had not been previously treated with levodopa. For the 11 patients who completed the 9 month trial, both Northwestern University Disability Scale and Columbia University Rating Scale scores were significantly reduced during bromocriptine therapy, when compared with either baseline or placebo scores. Two patients improved greater than 50% and had no side effects. Transient side effects appeared in four patients. Bromocriptine at doses of 20 mg/day or below may yield effective symptomatic improvement in de novo parkinsonism and may be considered as the initial treatment in young parkinsonian patients with only mild-to-moderate disability.