Clinical adherence of taking memantine in moderate-to-severe Alzheimer's disease in Taiwan

Abstract

Background: The prevalence ofAlzheimer’s disease (AD) is rising due to aging population in Taiwan. Use of the NMDA-receptor antagonist, memantine, has showed improvement in cognition, activity of daily living and neuro-behavior syndromes in patients with moderate to severe AD. Memantine seems to provide a distinctive tolerability with very mild side effects. Little is known about clinical adherence of takingmemantine in Taiwan. Our study is trying to elucidate factors associated with withdrawal of taking memantine.Methods: All of the recruited subjects were diagnosed with Alzheimer’s disease based on the DSM-IV criteria at the department of neurology, Kaohsiung Medical University, a medical center at southern Taiwan from Jan, 2008 to March, 2013. The neuropsychological assessment including clinical Dementia Rating Scale (CDR), Mini-Mental State Examination (MMSE) and cognitive abilities screening instrument (CASI) were performed at the beginning of taking memantine and at the next annual assessment. Subjects with moderate to severe AD having a baseline MMSE total score between 10 and 14 or CDR1⁄42 were eligible for the study. The clinical adherence of memantine to AD was examined by telephone interview with caregiver of AD patients and the therapeutic duration was recorded accordingly. Results: Twenty-seven subjects were enrolled in this study (3 males and 24 females; mean age,82.9 6 6.3 (mean6 SD); mean educational level, 4.0 6 3.9 year; mean CASI, 29.3 6 13.1; mean MMSE,9.2 6 3.5). The mean with mean therapeutic duration of memantine was 101.5 6 37.7 weeks among these 27 subjects. For 13 out of 27 discontinuing memantine, the main reasons accounting for the discontinue cause were unapproved by health care insurance (33.3%, 9/27) due to the advanced disease severity, transferred to other hospitals or nursing home (11.1%, 3/27) or death due tomultiple organ failure (3.7%, 1/27). There were no reported adverse effects for the continuous treatment for the other 14 (51.9%) patients keeping the continuous treatment.Conclusions:Memantine showed its potential with no reported adverse effect in the treatment of AD. The clinical adherence of memantine to the moderate to severe stage of AD was mainly determined by the national health insurance at Taiwan.