Despite continued research into dementia, few treatment options are available for cognitive symptoms. None of them halt or prevent deterioration, and their use is often governed by tolerability and efficacy. Cognitive enhancers, such as acetylcholinesterase inhibitors (AChE inhibitors – donepezil, rivastigmine and glantamine) and memantine are discussed in detail in this chapter.

When considering any treatment options, our aim should always be to enable the individual and the carers to live well with the dementia by improving quality of life. Depending on the underlying pathology of the dementia syndrome, treatment with cognitive enhancers such as AChE inhibitors or memantine can be considered.

People who notice a benefit from cognitive enhancers may experience symptomatic relief from cognitive and behavioural symptoms. These can manifest as improvements in motivation, concentration and general alertness but can come at the expense of certain side effects. Indeed, these medications will not be suitable in all cases.

As with all prescribing, a balance needs to be struck between risks and benefits. Where the occurrence of adverse side effects are determined to outweigh the possible benefits, consideration should be given to discontinuation or deciding not to commence the medication at all.

Careful discussion of these issues with the patient and carers is required to manage expectations from the outset, without falsely raising hopes and to dissuade from the notion that cognitive enhancers will halt disease progression.

AChE inhibitors and memantine can offer symptomatic treatment and there is no evidence to suggest that survival is affected. Treatment with AChE inhibitors can produce modest improvements in cognition, functional and behavioural symptoms as well as lowering care giver burden and delaying institutionalisation.

Absence of ‘close comparison’ studies suggests that available medications should be assumed to have parallel efficacy against cognitive symptoms. Each of the AChE inhibitors offers benefits over best supportive care.

Under clinical trial conditions if AChE inhibitors are given at optimal doses, roughly one-third of people would be expected to improve and around one-third would be expected not to deteriorate. These estimations appear to be echoed in practice. Memantine can have a small beneficial effect at 6 months in moderate-to-severe AD. Statistically significant effects were detected on cognition, activities of daily living and behaviour.