Benefit-risk considerations in the treatment of dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is a relatively recently characterised syndrome with clinical and pathological features that distinguish it from classical Alzheimer's disease. These characteristics include more rapid decline, spontaneous features of parkinsonism, visual hallucinations and fluctuating cognition. This article reviews the clinical syndrome of DLB and the agents used to treat its cognitive, motor and behavioural manifestations. Benefit-risk issues regarding the treatment of DLB are discussed based upon limited randomised, controlled clinical trials with some speculative conclusions being drawn from case reports and case series. We conclude that patients with DLB may respond better to cholinesterase inhibitors than patients with Alzheimer's disease on both cognitive and behavioural measures. Cholinesterase inhibitor therapy may result in reduced caregiver burden and less time institutionalised. These agents are well tolerated with the majority of adverse effects being gastrointestinal in nature. Although neuropsychiatric manifestations are numerous in patients with DLB, antipsychotics should be used infrequently and with caution, although atypical antipsychotics are better tolerated than conventional antipsychotics. Physicians should exhibit caution when prescribing these agents because of the increased risk of extrapyramidal adverse effects. Limited data suggest that the use of levodopa or other dopaminergic agents may be of benefit for the treatment of the parkinsonism that is associated with DLB. However, the increased risk of hallucinations and neuropsychiatric symptoms may negate the potential benefits of increased mobility. There is insufficient evidence to draw conclusions about the use of antidepressants; however, selective serotonin reuptake inhibitors may be of benefit.