Clinical and cost-effectiveness of donepezil, rivastigmine, and galantamine for Alzheimer's disease - A systematic review

Objectives: Systematic review of the clinical and cost-effectiveness of donepezil, rivastigmine, and galantamine for people suffering from Alzheimer's disease. Methods: Sixteen electronic databases (including MEDLINE, the Cochrane Library, and Embase) and bibliographies of related papers were searched for published/unpublished English language studies, and experts and pharmaceutical companies were consulted for additional information. Randomized controlled trials (RCTs) and economic studies were selected. Clinical effectiveness was assessed on measurement scales assessing progression of Alzheimer's disease on the person's global health, cognition, functional ability, behavior and mood, and quality of life. Cost-effectiveness was presented as incremental cost per year spent in a nonsevere state (by Mini Mental Health State Examination) or quality-adjusted life-year. Results: Twelve of 15 RCTs included were judged to be of good quality. Although donepezil had beneficial effects in Alzheimer's patients on global health and cognition, rivastigmine on global health, and galantamine on global health, cognition, and functional scales, these improvements were small and may not be clinically significant. Measures of quality of life and behavior and mood were rarely assessed. Adverse effects were usually mild and transient. Cost-effectiveness base case estimates ranged from pound2,415 savings to pound49,476 additional cost (1997 prices) per unit of effect for donepezil and a small savings for rivastigmine. Estimates were not considered robust or generalizable. Conclusions: Donepezil, rivastigmine, and galantamine appear to have some clinical effect for people with Alzheimer's disease, although the extent to which these translate into real differences in everyday life remains unclear. Due to the nature of current economic studies, cost-effectiveness remains uncertain and the impact on different care sectors has been inadequately investigated. Further research is needed to establish the actual benefits of acetylcholinesterase inhibitors (AChEls) for people with Alzheimer's disease and their caregivers, the relationship of these changes to clinical management, and careful prospective evaluation of resource and budgetary consequences.