Rivastigmine in Parkinson's disease dementia

Dementia associated with Parkinson's disease (PD) ultimately develops in approximately 70% of patients with PD older than 80 years of age. The neuropathology of PD dementia (PDD) is likely multifactorial and affects several neuronal populations. There is evidence that PDD is associated with a cholinergic deficit, supporting the therapeutic role of cholinesterase inhibitors, which are already first-line agents in the treatment of Alzheimer's disease. Open-label and small controlled studies suggested a clinical efficacy of cholinesterase inhibitors in PDD. One large randomized placebo-controlled trial of 541 patients demonstrated that oral rivastigmine improved cognition, attention and executive functions, activities of daily living and behavioral symptoms after 6 months of treatment. Rivastigmine is a dual cholinesterase inhibitor, being effective on both acetylcholinesterase and butyrylcholinesterase. This paper reviews the pharmacokinetic and pharmacodynamic properties of rivastigmine (oral and transdermal administration). It also reviews evidence on clinical efficacy, safety and tolerability of the oral administration in PDD patients at doses of 3-12 mg/day.