Clinical Benefits of Memantine Treatment for Alzheimer’s Disease in the Okayama Memantine Study II (OMS II)

Abstract

The clinical benefits of memantine, depending on the baseline cognitive and affective conditions in real world dementia clinics, have not been completely examined. We performed the “Okayama Memantine Study II (OMS II)” to retrospectively evaluate the clinical effects of memantine monotherapy (n = 38) in Alzheimer’s disease (AD) patients using seven batteries to assess dementia at the baseline, at 3, 6, and 12 months. Additionally, we divided 163 AD patients treated with memantine into two subgroups depending on the baseline cognitive score of the Mini-Mental State Examination (MMSE): the MMSE <15 group (n = 36) and the baseline MMSE ≥15 group (n = 127). We also analyzed 71 AD patients based on the baseline behavioral and psychological symptoms of dementia (BPSD) severity using Abe’s BPSD score (ABS). Memantine monotherapy maintained cognitive functions until 6 months of treatment, but showed a decrease at 12 months ( ^*p <  0.05 versus baseline). However, memantine monotherapy greatly improved BPSD symptoms until 12 months ( ^*p <  0.05,  ^**p <  0.01) and maintained other affective functions as well as the activity of daily living. Memantine treatment showed similar effects, regardless of the baseline cognitive functions, but showed better effects on ABS for higher baseline cognitive functions. Memantine treatment greatly improved ABS depending on baseline BPSD severity. Our present OMS II showed that memantine monotherapy improved BPSD until 12 months. The higher baseline cognitive subgroup (MMSE ≥15) and the worse baseline BPSD subgroup were expected to show better effects with memantine.