Memantine benefits functional abilities in moderate to severe Alzheimer's disease

Abstract

Objective: Functional abilities are severely impacted in Alzheimer's disease (AD). Loss of the ability to perform complex (instrumental) and basic activities of daily living (ADL), leads to decreased independence and increased caregiver burden. This post-hoc analysis investigated the effect of memantine (20 mg/day) on ADLs, as measured by Alzheimer's Disease Cooperative Study-Activities of Daily Living 19-item (ADCS-ADL19) and 23-item (ADCS-ADL23) scales, in patients with moderate-to-severe AD.

Design: Data were pooled from six multicenter, randomized, placebo-controlled, double-blind, 6-month studies of memantine 20 mg/day.

Participants: Male and female patients aged ≥ 50 years at baseline with a Mini Mental State Examination (MMSE) score < 20.

Measurements: ADCS-ADL19 and ADCS-ADL23 scales were pooled, and 14 shared items, with a score range of 0-45, were identified and included in the analysis (ADL14). Basic ADLs (BADLs) were defined as: eating, walking, toileting, bathing, and grooming. Instrumental ADLs (IADLs) were defined as: using a telephone, watching television, conversing, clearing a table, finding belongings, obtaining a beverage, disposing of household rubbish, travelling outside the house, and being left alone. Changes from baseline on single-item, BADL (range: 0-15), IADL (range: 0-30), and total ADL14 scores were analysed for observed cases using ANCOVA, with study, center and treatment as categorical explanatory variables and score at baseline as a covariate.

Results: 959 patients were treated with memantine and 867 patients received placebo. Memantine-treated patients had less decline from baseline on the ADL14 total score, compared with placebo (p < 0.001) at study end. Memantine also showed lower reductions in BADLs (p < 0.05) and IADLs (p < 0.001), for observed cases, compared with placebo. Memantine-treated patients showed less worsening than placebo recipients for the ADL items: toileting (p < 0.01), grooming (p < 0.01), finding belongings (p < 0.01), and travelling outside the house (p < 0.05).

Conclusion: Compared with placebo, memantine shows benefits for both basic and instrumental ADLs in patients with moderate-to-severe AD, suggesting that memantine treatment may lead to a more interactive and dignified life for patients with moderate-to-severe AD.

Figure 1

Mean change from baseline in ADL₁₄ total score, at Weeks 4, 12 and 24/28 (observed cases) and at Week 24/28 (last observation carried forward) in the pooled population of patients with moderate to severe AD. P-values from ANCOVA

Figure 2

Mean change from baseline in ADL₁₄ BADL and IADL score at Week 24/28 (observed cases) in the pooled population of patients with moderate to severe AD. P-values from ANCOVA

Figure 3

Mean change from baseline in ADL single-item scores at Week 24/28 (observed cases)