by Alzheimer's Research UK

Diagram of the brain of a person with Alzheimer's Disease. Credit: Wikipedia/public domain.

Newly-released follow-up analysis from a 2012 clinical trial led by a UK-based research team suggests that continuing treatment of the commonly-prescribed dementia drug donepezil into the later stages of Alzheimer's could reduce a person's likelihood of moving into a nursing home.

As part of an original clinical trial called DOMINO-AD (Donepezil and Memantine in Moderate to Severe Alzheimer's Disease), which reported its primary outcome data in 2012, a UK-wide team of researchers and clinicians recruited 295 study volunteers from 15 different memory centres across England and Scotland. All of the volunteers had a diagnosis of moderate to severe Alzheimer's disease and had been taking the drug donepezil for at least 3 months. They had to have been taking a dose of 10mg donepezil per day for at least the last six weeks and were living at home – either independently or with a family member.

Donepezil (also known by the brand name Aricept) is one of the few drugs available to help with the symptoms of Alzheimer's disease. It currently has a licence in the UK for people with mild to moderate Alzheimer's and its use in the NHS is recommended for people at these stages of their illness. A second drug called memantine is recommended for use in people with severe Alzheimer's.

The original trial set out to investigate whether continued treatment with donepezil could also have benefits for those with severe Alzheimer's, either alone or in combination with memantine. The researchers compared this to people who were taken off the drug completely. The team did this through a multi-centre, randomised, placebo-controlled clinical trial over 52 weeks.

The trial results announced in 2012 suggested modest benefits on memory and thinking and day-to-day activities in those people who continued to receive donepezil compared to those taken off the drug. While this was the primary outcome of the trial, the researchers have completed a secondary analysis of the data to investigate whether the different combinations of drugs allowed people with Alzheimer's to live at home for longer.

After the initial 52 weeks of defined treatment, the volunteers' ongoing treatment was decided by their individual doctors. The research team recorded where each volunteer was living at the end of the 52 week period, as well as following the volunteers with phone calls for a further three years to find out if and when they had moved into a nursing home.

The team found that those volunteers who had continued treatment with donepezil were less likely to move into a care home in the first year of the study than those who had been taken off the drug. After the first year, this benefit was no longer apparent, with no difference in the number of people who moved into nursing homes between the different treatment groups over the following three years. They also found that starting treatment with memantine had no impact on whether someone moved into a care home over the course of the study.

Dr Simon Ridley, Director of Research at Alzheimer's Research UK said:

"This study is not testing new treatments for Alzheimer's but looking at the effectiveness of current symptomatic treatments in people in the later stages of the disease. The new analysis builds on an earlier clinical trial that reported modest benefits on cognition and day-to-day activities when treatment with the drug donepezil was continued into the later stages of Alzheimer's. While the findings suggest that treatment with donepezil in people with advanced Alzheimer's could help them to stay at home for longer, the authors highlight that the results are exploratory and we know that the factors influencing a move to care are complex.

"This study addresses the important issue of improving treatment for those in the moderate to severe stages of Alzheimer's disease. With only a handful of symptomatic treatments available to treat Alzheimer's, it is vital that we better understand the most effective ways to use these drugs to help improve quality of life. Increased investment in dementia research is critical, both to improve the use of current symptomatic treatments and to find treatments that can halt the spread of damage through the brain."

Provided by Alzheimer's Research UK