A comparison of piribedil, procyclidine and placebo in the control of phenothiazine-induced parkinsonism.

A double-blind, cross-over trial of the effectiveness of piribedil, procyclidine and placebo in the control of parkinsonism induced by fluphenazine decanoate was conducted in sixteen cases of chronic schizophrenia. Procyclidine was shown to be more effective and piribedil less effective than the placebo. Piribedil produced a number of unpleasant effects, including headache, vomiting and malaise.