Efficacy and Tolerability of a Combination Treatment of Memantine and Donepezil for Alzheimer's Disease: A Literature Review Evidence

Introduction

Alzheimer's disease (AD) is the most common form of dementia in the elderly. This disorder is characterized by cognitive decline, impaired performance of activities of daily living, and behavioral and psychiatric symptoms. The frequency of dementia, especially AD, increases exponentially with age, and it affects 1 in 10 people over 65 years of age and about half the people over 85.1, 2 It is estimated that 25–30 million people worldwide currently suffer from AD and the number of cases will triple by 2040.3 Importantly, AD is the leading cause of disability, institutionalization, and increased mortality in older people in western countries.4, 5 Hence, the magnitude of this devastating disease has a great impact on caregivers and health care systems. Even more, the burden that AD imposes on society is enhanced by the fact that there are no currently curative treatment options for this entity.

Abstract

INTRODUCTION

Two types of drugs have been approved for the symptomatic treatment of Alzheimer's disease (AD): the cholinesterase inhibitors (ChEIs) and memantine. There is a growing interest to know whether the combination of these drugs is safe and if it adds any clinical benefit to patients.

OBJECTIVE

To systematically review published medical literature assessing the efficacy and tolerability of a combination treatment of memantine and donepezil in AD patients.

METHODS

We searched PubMed for English and Spanish-language literature, using the terms “Alzheimer′s disease,” “cholinesterase inhibitors,” “donepezil,” and “memantine.” Our review focused on clinical trials and observational studies.

RESULTS

Eleven publications representing seven unique studies were selected for this review. Three were randomized double-blind, placebo-controlled trials and four were observational studies.

CONCLUSIONS

Available data revealed that the combination of memantine and donepezil slowed down cognitive decline, prolonged functional independence, and improved behavioral symptoms in patients with moderate to severe AD. The long-term use of the dual therapy decreased the risk of nursing home admission. More longitudinal studies are needed to further examine the role of combined therapy in the management of AD patients.

Keywords

Alzheimer's disease, memantine, donepezil, cholinesterase inhibitors, combined therapy