Objectives: To evaluate the safety and efficacy of long-term treatment with rivastigmine (3-12 mg/day) and its effects on neuropsychiatric and behavioral disturbances in nursing home patients with moderate to severe probable Alzheimer's disease (AD).
Methods: A prospective, multicenter 26-week open-label extension to a 26-week open-label study (52 week results) of rivastigmine treatment in patients with Mini-Mental State Examination (MMSE) scores of 6-15 inclusive, residing in nursing homes at 13 centers in the US. Effects of treatment with rivastigmine for up to 52 weeks on neuropsychiatric and behavioral symptoms were examined using the Neuropsychiatric Inventory-Nursing Home (NPI-NH) scale. Cognitive function was assessed by the MMSE, and the Naming Objects and Fingers Test (NOFT) subset of the Alzheimer's Disease Assessment Scale -- Cognitive subscale (ADAS-Cog). Global functioning was assessed using the simplified Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus).
Results: Rivastigmine (3-12 mg/day) significantly improved neuropsychiatric and behavioral symptoms compared to baseline (in patients with specific behavioral disturbances at baseline) in observed cases (OC) and last observation carried forward (LOCF) analyses. Over 52 weeks, treatment with rivastigmine significantly improved 10 of 12 individual NPI-NH domains from baseline in LOCF patients with symptoms present at baseline. Cognitive function was stable, indicated by the lack of decline in MMSE and the NOFT. Global function was stabilized or improved in greater than half of the patients as indicated by the simplified CIBIC-Plus scores.
Conclusion: Rivastigmine showed potential benefit in the long-term treatment of behavioral symptoms as well as cognitive and global functioning in nursing home residents with moderate to severe AD with concurrent behavioral symptoms present at baseline. Although these results suggest that treatment with rivastigmine may have beneficial behavioral effects and cognitive benefits on patients with moderate to severe AD, they are subject to the limitations of an open-label study.