An evaluation of bromocriptine in the treatment of Parkinson's disease.

22 patients entered a double-blind trial to test the efficacy of bromocriptine therapy in patients with Parkinson's disease already established on conventional levodopa therapy. 3 patients on placebo withdrew when no improvement occurred and control became complicated. 4 patients on active drug withdrew because of various symptoms, but in only 1 case were these (nausea and vomiting) thought to be a real drug effect. Of the 15 patients who completed the trial, 9 were on active drug and 6 were on placebo. Although more than half the patients in each group were subjectively improved, measurement scales of functional disability and physical examination revealed no significant change in either group. Side effects encountered included nausea, dyskinesiae and hallucinations. It is concluded that bromocriptine does not offer any additional benefit in most patients with Parkinson's disease who are well stabilised on levodopa therapy, but may have a place in those patients who encounter side effects due to fluctuations in serum and tissue levels of levodopa.