Cognitive performance in Alzheimer's disease patients receiving rivastigmine for up to 5 years.

This analysis aimed to assess mini-mental state examination (MMSE) scores in patients with Alzheimer's disease who received rivastigmine, an inhibitor of acetylcholinesterase and butyrylcholinesterase, for up to 5 years. Rivastigmine data came from two pooled open-label extensions of four 6-month, randomised, placebo-controlled trials. Projections of decline, had the same patients not been treated, were made using a baseline-dependent mathematical model. MMSE data were available for 1998 rivastigmine-treated patients and 657, 298 and 83 were still on treatment at 3, 4 and 5 years, respectively. The mean (+/-SD) baseline MMSE score was 19.3 (+/-4.9). Projected mean scores in model-based untreated patients declined below 10 points on the MMSE at about 3 years, while the mean MMSE score of patients who remained on rivastigmine stayed above 10 points for 5 years.

Efficacy of rivastigmine in subjects with moderately severe Alzheimer's disease.

BACKGROUND: Cholinesterase (ChE) inhibitors are primarily used in the treatment of mild to moderate Alzheimer's disease (AD), but may also be effective in more severe disease. OBJECTIVE: To evaluate the dual ChE inhibitor, rivastigmine, in more severe dementia. METHODS: We retrospectively analysed pooled data from three randomised, placebo-controlled, double-blind, 6-month trials, involving 2126 AD subjects. Subjects were selected according to baseline Mini-Mental State Examination (MMSE) score to identify subjects with more severe cognitive impairment (10-12 MMSE points). One-hundred-and-seventeen subjects were included who had been treated with rivastigmine 6-12 mg/day or placebo. The AD Assessment Scale-Cognitive Subscale (ADAS-Cog), the MMSE, a six-item subscore of the Progressive Deterioration Scale (PDS) and the BEHAVE-AD assessed efficacy. Tolerability was assessed by recording adverse events (AEs) and the relative risk (RR) of discontinuation. RESULTS: This group of subjects responded well to rivastigmine. After 6 months, the mean ADAS-Cog score declined by 6.3 points in the placebo group and increased by 0.2 points in the rivastigmine group (observed cases; p<0.001). Clinical benefits were also observed with the MMSE, the six-item PDS score and items of the BEHAVE-AD. Rivastigmine showed the same pattern of AEs as in other studies, but the RR of dropping out due to AEs was lower than in subjects with milder AD. CONCLUSION: Current treatment guidelines do not recommend treating individuals with severe AD with ChE inhibitors. However, this retrospective analysis suggests that rivastigmine 6-12 mg/day may benefit subjects with more severe disease, as well as subjects with mild to moderate impairment.