The addition of bromocriptine to long-term dopa therapy in Parkinson's disease.

This open trial is a study of the effect of adding bromocriptine (BC) to the treatment of patients who had taken a dopa-containing preparation (LD) for many years. Sixty-five patients entered the trial at an average age of 66.6 years. The mean duration of Parkinson's disease was 12.74 years and LD had been taken by one-half of them for more than 10 years and by an additional 27% for longer than 5 years. The duration of treatment with BC exceeded 2 years in 45% of cases and the average dose of BC was 19.27 mg/day. On the Hoehn and Yahr scale 70.8% of patients were classified as between stages II and IV, 24.6% were in stage I and 4.6% were in stage V. Dopa-induced involuntary movements were observed in 60% of patients at the beginning of the trial but were present in only 25% at the completion, due to the dopa-sparing effect of BC allowing a reduction of the dose of LD by an average of 34%. End-of-dose failure was reduced only slightly and on-off oscillations were not influenced by the addition of BC to LD. Tremor, rigidity, akinesia and dysarthria improved in 22% of all patients but BC offered no beneficial effect on the various gait disorders of Parkinson's disease. The conclusion of the study is that 47.7% of patients felt that the addition of BC to LD had reduced their involuntary movements and the disabilities of their disease.