Delirium (acute confusion) is a highly prevalent condition among hospitalized elders with substantial morbidity within the hospital and beyond. Particular patient populations are at high risk for poor outcomes after an episode of delirium. Patients with hip and other long bone fractures are at increased risk of developing delirium (acute confusion) which impedes functional recovery. This is a pilot study to test the tolerability and efficacy of donepezil, a cholinesterase inhibitor medication used commonly in persons with dementia, for the prevention of new or worsening delirium in aged hip and other long-bone fracture patients. Additional purposes involve gathering a small amount of patients' serum to better understand the pathophysiology of delirium in this population.

The purposes of this pilot study are to determine: 1) the safety and tolerability a cholinesterase inhibitor medication) in aged hip and long bone fracture patients, 2) To obtain estimates of subject accrual and preliminary estimates of effect size on the development of new delirium symptoms to allow for planning of a larger, definitive trial, 3) To better understand the underlying causes of delirium by examining whether a measure of blood anticholinergic activity relates to the incidence and persistence of delirium symptoms, and 4) To explore the interaction between anticholinergic activity, donepezil therapy, and delirium symptoms.