A nation-wide collaborative study on the long-term effects of bromocriptine in patients with Parkinson's disease. First interim report in Japan.

Two prospective projects were started in May 1985 to evaluate the long-term effects of bromocriptine in patients with Parkinson's disease. One of the projects is to see if combination therapy with levodopa and bromocriptine is superior to levodopa alone with regard to the prevention of late side effects of levodopa therapy. The other is to see the long-term effects of bromocriptine monotherapy. Patients with Parkinson's disease were allocated randomly to either combination or levodopa group in the first project. Parkinsonian symptoms, disabilities of daily life and severity of late side effects of long-term levodopa therapy were evaluated by a semiquantitative rating scale. This communication represents the first interim report. Methods of the studies and synopsis of the results at the end of the 12th month are described. A total of 702 patients was enrolled in the study (combination therapy, n = 216; levodopa therapy, n = 200, bromocriptine monotherapy, n = 286). At the end of the 12th month, the numbers of patients who dropped out from the study were 19, 16 and 55 in the three groups, respectively. It appears to be too early to make any definite conclusion with regard to which mode of treatment is superior, however, some evidence suggesting a superiority of the combination therapy over levodopa alone was noted in managing wearing-off phenomenon and dyskinesia. As many patients are sticking to the originally intended mode of treatment, it appears to be possible to obtain more meaningful data in several years.