Effects of memantine on behavioural symptoms in Alzheimer's disease patients: an analysis of the Neuropsychiatric Inventory (NPI) data of two randomised, controlled studies.

INTRODUCTION: Behavioural symptoms are common in moderate to severe Alzheimer's disease (AD). We have analysed the databases of two randomised studies with regard to the effects of memantine treatment on behavioural symptoms, measured using the 12-item version of the Neuropsychiatric Inventory (NPI). SUBJECTS: The monotherapy study (memantine only) reported by Reisberg et al. (2003) involved 252 patients with baseline MMSE total score of between 3 and 14, whereas the combination study (memantine and donepezil) reported by Tariot et al. (2004) comprised 404 patients with MMSE scores of between 5 and 14. In both studies, patients received 10 mg memantine b.i.d. or matching placebo, and lived in the community. METHODS: For both studies NPI total and individual domains scores were analysed in the ITT population. For the monotherapy study a dichotomised analysis was performed separately for patients who had behavioural symptoms at baseline and for those without pre-existing symptoms. Furthermore, a factor analysis was used to identify any behavioural clusters within the patient population. RESULTS: In both studies, the change in NPI total scores at endpoint was consistently in favour of memantine treatment, reaching statistical significance in the combination study (p = 0.002). Memantine treatment showed a significant beneficial effect in comparison to placebo treatment in the NPI agitation/aggression domain in both studies (p = 0.008; p = 0.001). The dichotomised analysis of the monotherapy study showed that there was significantly less agitation/aggression emerging in the memantine-treated group compared to placebo (p = 0.003). Factor analysis showed that hyperactivity accounted for 27% of the data variance. CONCLUSIONS: Memantine has a beneficial effect on the behavioural symptoms of patients with moderate to severe AD, with the most pronounced effect on agitation/aggression.

Specific functional effects of memantine treatment in patients with moderate to severe Alzheimer's disease.

Treatment of Alzheimer's disease (AD) that combats progressive functional deterioration can improve the patient's quality of life and reduce caregiver burden. Memantine, a moderate affinity N-methyl-D-aspartate receptor antagonist, reduces global deterioration in AD patients and provides cognitive and functional benefits relative to placebo. Two previous studies reported statistically significant benefits of memantine for overall functional ability on the Alzheimer Disease Cooperative Study Activities of Daily Living Inventory modified for severe dementia (ADCS-ADL(19)), Functional Assessment Staging, and G2 scale. The present study reports a single-item analysis of the ADL scales from the two trials and shows that patients treated with memantine demonstrated a numerical advantage over placebo on all items assessed. These results help to translate the positive effects of memantine into specific aspects of functional ability, information that is relevant to AD patients and their families as well as to researchers interested in the assessment of functional ability in AD clinical trials.