Question: In adults with Alzheimer’s dementia, how long are cholinesterase inhibitors effective?

Answer:

Evidence on the duration of effectiveness of cholinesterase inhibitors was very limited. There was good evidence, from two systematic reviews, that cholinesterase inhibitors can provide short term (six months) benefits in patients with mild to moderate Alzheimer's disease. Data from one randomised controlled trial (RCT) and one an observational study, which used follow-up data from participants in the galantamine arms of three RCTs, suggest that continued galantamine treatment beyond 12 months may be effective in slowing cognitive decline. However, it should be noted that the RCT found no statistically significant differences between the continued galantamine and discontinuation groups in either the number of participants withdrawn from the study due to a change in Assessment Scale Cognitive subscale (ADAS-cog) score ≥4, or the mean global assessment with carer input (CIBIC-plus) score. Further, no study included in this evidence summary reported data showing any statistically significant treatment effect for cholinesterase inhibitors (compared with placebo) beyond six months. Further research is required to establish the longer term effectiveness of cholinesterase inhibitors in the management of patients with Alzheimer's disease.