Long-term Safety of Rivastigmine in Parkinson Disease Dementia: An Open-Label, Randomized Study

Objective: This study investigated the long-term safety of rivastigmine (12 mg/d capsules, 9.5 mg/24 h patch) and effects on motor symptoms in patients with mild-to-moderately severe Parkinson disease dementia. Methods: This was a 76-week, prospective, open-label, randomized study in patients aged 50 to 85 years. Primary outcomes included incidence of, and discontinuation due to, predefined adverse events (AEs) potentially arising from worsening of Parkinson disease motor symptoms with capsules. Secondary outcomes included frequency of AEs/serious AEs. Efficacy outcomes included Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), Neuropsychiatric Inventory (NPI-10), and Mattis Dementia Rating Scale (MDRS). Results: Five hundred eighty-three patients were randomized to rivastigmine capsules (n = 295) or patch (n = 288). Incidence of predefined AEs was 36.1% for capsules, 31.9% for patch; discontinuation due to worsening of motor symptoms was 4.4% and 2.4%, respectively. Most common AEs were nausea (capsules, 40.5%; patch, 8.3%), tremor (24.5%; 9.7%), fall (17.0%; 20.1%), vomiting (15.3%; 2.8%), and application site erythema (0%; 13.9%). Significant efficacy in favor of capsules was observed at weeks 24 to 76 on MDRS; 24 and 76 on NPI-10; weeks 52 and 76 on ADCS-ADL. In patients with Mini-Mental State Examination (MMSE) greater than 21, no differences in efficacy on MDRS and ADCS-ADL were observed at any time point; significant differences in favor of capsules were maintained in patients with MMSE less than or equal to 21. Conclusions: This study supports the long-term safety of rivastigmine in Parkinson disease dementia. The rate of worsening of motor symptoms was in the range expected due to the natural progression of Parkinson disease, no new or unexpected safety issues emerged in the long-term.