薬理と治療

Abstract

Background Alzheimerʼs disease（AD）is a progressive neurodegenerative disease, the core symptom of which is cognitive dysfunction. Memantine（MMT）is a renally excreted drug that is used in the treatment of AD; it is necessary to adjust the dose according to the renal function. However, there are no reports related to the renal function and adverse reactions. Method We retrospectively investigated the medical records of 253 AD patients in whom MMT treatment was started in the Department of Neurology, Fukuoka University Hospital between July 2011 and June 2016（male, n＝110；female, n＝143；mean age, 81.5 ±7.8 years）. In 95 patients（37.5％）, MMT treatment was reduced or discontinued within 52 weeks after its initiation. Results Nervous system symptoms were the most common reason for discontinuation╱dose reduction. The risk factors for MMT discontinuation or dose reduction due to adverse reactions included female sex and a maximum MMT dose of≤10 mg. In comparison to the group with a good renal function（eGFR≥45 mL╱min）, the rate of MMT discontinuation or dose reduction was significantly higher（P＜0.01）in the renal malfunction group（eGFR ＜45 mL╱min）. The rates of discontinuation╱dose reduction according to the creatinine clearance rate（CCr）were as follows: CCr＞50 mL╱min, 21.1％；CCr 30-50 mL╱min, 48.1％；and CCr＜30 mL╱min, 55.6％. Conclusions The renal function is an important factor in avoiding adverse reactions in MMT-treated patients; thus, it is also suggested that it is more likely to cause adverse reaction by gradual increase of MMT in patients with a CCr of＜30-50 mL╱min.