(Medical Xpress) -- Memantine, a drug used to treat patients with Alzheimers disease, is ineffective for people with Downs syndrome aged 40 and over, according to a study led by researchers at Kings and published in The Lancet.
Clinically significant Alzheimers-like pathological features develop in all people with Downs syndrome by 40 years of age. Almost 40 per cent of people with Downs syndrome who are 60 years or older have a diagnosis of dementia, although such a finding is not straightforward because of an absence of validated approaches for people with intellectual disabilities.
Dementia in Downs syndrome is a key clinical challenge, especially as people with Downs syndrome live longer than they used to, with a high proportion of individuals living to 60 years or beyond. Despite the introduction of antenatal screening in the UK in 1990, the incidence of Downs syndrome had decreased by only one per cent by 2008.
The study enrolled adults over the age of 40 with Downs syndrome, and with or without Alzheimers, at four learning disability centres in the UK and Norway.
Participants received memantine (88 patients) or a placebo (85) for 52 weeks, with the randomisation balanced according to sex, dementia, age group, total Downs syndrome attention, memory, and executive function scales [DAMES] score, and centre. The primary outcome was change in cognition and function, measured with DAMES scores and a standard assessment tool called the adaptive behavior scale (ABS).
Both groups declined in cognition and function but rates did not differ between groups for any outcomes. Ten (11 per cent) of 88 participants in the memantine group and six (seven per cent) of 85 controls had serious adverse events. Five participants in the memantine group and four controls died from serious adverse events.
Professor Clive Ballard, from the Wolfson Centre for Age-Related Diseases at Kings, says: Memantine is not an effective treatment in this group of patients. We believe that this robust finding will have implications for clinical practice and research strategy in the future. Specifically, therapies that are beneficial for people with Alzheimers disease are not necessarily effective for the treatment of cognitive impairment or dementia in the context of Downs syndrome.
Dr. Anne Corbett, Research Manager at Alzheimers Society (UK), and co-author said: So little is known about the best way to treat dementia in people with Downs syndrome. Further investment is urgently needed to develop treatments that are effective in this important group of people.
More information: See the full study and accompanying article