Analysis of the Effect of Memantine in Reducing the Worsening of Clinical Symptoms in Patients with Moderate to Severe Alzheimer’s Disease

<i>Background:</i> Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and delaying disease worsening is a relevant treatment outcome. <i>Methods: </i>Data from 6 randomized, double-blind, placebo-controlled, 6-month studies were pooled and a subgroup of patients (867 on placebo, 959 on memantine) with moderate to severe AD (Mini- Mental State Examination <20) was analyzed. ‘Any clinical worsening’ was defined as a decline on the Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-cog) or the Severe Impairment Battery (SIB) and on the Clinician’s Interview-Based Impression of Change Plus Caregiver Input (CIBIC-plus) and the Alzheimer’s Disease Cooperative Study – Activities of Daily Living Inventory (ADCS-ADL), and ‘marked clinical worsening’ as ≧4 points decline on the ADAS-cog or ≧5 points on the SIB and decline on the CIBIC-plus and the ADCS-ADL. <i>Results:</i> More placebo-treated than memantine-treated patients showed any clinical worsening (28 vs. 18%; p < 0.001), and 21% placebo-treated patients compared to 11% memantine-treated patients had marked clinical worsening (p < 0.001). <i>Conclusion:</i> In this population of moderate and severe AD patients, treatment with memantine was associated with reducing worsening of clinical symptoms in AD during the 6-month study period.