ACHE and Parkinson disease: In another attempt to improve gait and reduce falls by manipulating cholinergic pathways, donepezil (a centrally acting inhibitor of AChE) was administered to 23 subjects with PD who reported falling or nearly falling more than 2 times per week.60 The study was designed as a randomized, placebo-controlled, crossover trial, with treatment phases of 6 weeks and a 3-week wash-out period in between.