Does combined levodopa and bromocriptine therapy in Parkinson's disease prevent late motor complications? Comparison of lisuride and bromocriptine in the treatment of advanced Parkinson's disease. [Bromocriptin in the treatment of progressive stages of Parkinson's disease (author's transl)].
Levodopa-carbidopa (LD) in low dosages adequately controls symptoms in most patients with Parkinson's disease and delays the appearance of fluctuations and dyskinesias. It has been suggested that early combination therapy with bromocriptine and levodopa delays or prevents the onset of late treatment complication associated with LD monotherapy in Parkinson's disease. We have conducted this study to assess the possible benefit of combined therapy compared with levodopa monotherapy. Seventy-eight previously untreated patients with Parkinson's disease were recruited over a period of 54 months and randomly allocated to either a levodopa-carbidopa (LD) Group or a levodopa-carbidopa in combination with low-dose bromocriptine (LD-Br) Group. The appearance of motor complications determined the end point of the study. We gradually increased the doses of bromocriptine (2.5-15 mg/d) or levodopa (125-500 mg/d) until the maximum "on" time was reached. In six patients, the doses of levodopa had to be increased up to the optimal dose (625-1000 mg/day). In the last evaluation the on-time and parkinsonian disability were similar in both treatment groups. We did not find statistically significant differences in the frequency of motor complications when comparing the two groups of treatment. Our study suggests that early combination of levodopa and bromocriptine does not confer any clinical benefit over levodopa alone in treating early Parkinson's disease, nor will it influence the evolution of the disease.Copyright Lippincott-Raven Publishers Twenty patients with advanced idiopathic Parkinson's disease were studied, all having a deteriorating response to levodopa and suffering from daily fluctuations in disability. A double-blind randomized cross-over study was conducted. Basic levodopa and anticholinergic treatment was continued unchanged in all patients. The dose increment period of 4-8 weeks was followed by a 4 week treatment period on a fixed optimal dose. In both treatment groups the mean optimal daily dose of lisuride was 1.3 mg (range 0.2-2.4 mg) and that of bromocriptine about 15 mg (range 3.75-30.0), without any significant differences between the treatment groups. The addition of lisuride or bromocriptine to levodopa treatment resulted in a significant and equal further improvement of parkinsonian disability. The therapeutic profiles of both lisuride and bromocriptine were similar. There was significantly more improvement in tremor than in other parkinsonian symptoms. Both lisuride and bromocriptine elicited a significant improvement in fluctuations of disability. No significant differences between the treatments were observed. The occurrence of clinical side effects seemed to be similar with both treatment regimens. In advanced parkinsonian patients the therapeutic efficacy of lisuride seems to be equal to that of bromocriptine as far as parkinsonian disability and fluctuations in disability are concerned. Forty patients with severe Parkinson's disease (23 men, 17 women) who had been treated for six years with L-dopa-decarboxylase inhibitor, were part of a placebo-controlled double-blind trial to test the effectiveness of bromocriptin. In all patients the effectiveness of L-dopa had been decreasing, 34 patients had L-dopa-induced dyskinesias, 35 "on-off" symptoms. Bromocriptin dosage was gradually increased to a total dose of 30 - 40 mg daily. This led to a 25% reduction in L-dopa requirements. The symptoms of Parkinson's disease were favourably influenced, with rigor, tremor and also walking disturbances responding better than bradykinesia of the hands. At the same time, there was a marked prolongation of the periods of good mobility ("on" time) from 7 to 10.8 hours without influence on other "on-off" symptoms such as paradoxical akinesia. Two patients had to be excluded from the trial because the treatment caused side effects (orthostatic hypotension, exogenous psychotic symptoms). Other side effects, such as nausea and mild forms of collapse, could be controlled by drugs.
Based on a qualitative review of the available data we conclude that in the treatment of early Parkinson's disease, bromocriptine may be beneficial in delaying motor complications and dyskinesias with comparable effects on impairment and disability in those patients that tolerate the drug.