Rivastigmine tartrate with a focus on dementia associated with Parkinson's disease

Abstract

Parkinson's disease is associated with dementia in about 40% of cases, and in time up to 80% of patients will develop dementia. This dementia is characterized by deficits in attention, executive function and memory. While, as in Alzheimer's disease, cholinergic dysfunction has long been identified to be related to the cognitive impairment in Parkinson's dementia, the fear of exacerbating the motor symptoms of the disorder has greatly hindered research into the anticholinesterases as symptomatic treatments for the cognitive and psychiatric deficits. However, following a number of successful open-label trials with anticholinesterases, a large, international, randomized, double-blind, placebo-controlled trial of the effects of rivastigmine in the dementia associated with Parkinson's disease has been conducted. Rivastigmine was found to significantly improve all of the primary and secondary endpoints in the study, showing benefits to cognitive function, neuropsychiatric complaints and activities of daily living. Cognitive improvements were seen on the Alzheimer's Disease Assessment Scale cognitive subscale, the Mini Mental State Examination, the attention battery of the Cognitive Drug Research computerized assessment system, word fluency and clock drawing. An open-label extension to the study suggested that the beneficial effects persisted up to 48 weeks. While the improvements seen with rivastigmine on the various measures have been described as modest by some commentators, rivastigmine is now widely registered for the symptomatic treatment of mild to moderate dementia associated with Parkinson's disease. A treatment is now available for a previously unmet medical need.