A double-blind study of the effects of levodopa in parkinson’s disease

Abstract

Both the independent analysis and the crossover analysis have shown that L-dopa was preferred over procyclidine hydrochloride and lactose in this double-blind study. Although side effects were frequent and caused 4 patients to discontinue L-dopa, nevertheless, the remaining 25 patients readily accepted this medication. Twenty-one of 30 patients enjoyed a 505% or greater improvement after the initial period of six weeks. An additional 7 patients who had less impressive early responses demonstrated a 19% or greater improvement after prolonged therapy. Patients given placebo or standard antiparkinsonian medicine on the first trial always were willing to give it up to try “something else.” Twenty-nine of 30 patients were satisfied with L-dopa the first time they received it and had no interest in giving it up to try the other drugs in the study. © 1971 American Academy of Neurology.