Disappointing result for strategies to delay Alzheimer’s disease
Vitamin E failed to delay progression to Alzheimer’s disease |
Donepezil (Aricept) may have a small beneficial effect on clinical progression to Alzheimer’s disease among patients with mild cognitive impairment, according to US researchers. However, they report that vitamin E provides no such benefit in these patients.
The researchers studied the effects of the two treatments among 769 subjects
who displayed memory loss and memory deficits but who did not have dementia.
By the end of the study, three years later, Alzheimer’s disease
had developed in 212 of the subjects.
There was a disappointing lack of efficacy for vitamin E, which, say
the researchers, has previously been shown to delay important milestones
in the clinical course of moderately severe Alzheimer’s disease.
Similarly, for donepezil, there was no reduction in the probability of
progression over the three years of the study. But an analysis of the
data revealed that progression to Alzheimer’s disease was less
likely for patients treated with donepezil for the first 12 months of
the trial. And the cognitive function of these subjects did not decline
on most measures during the first six to 18 months of the study.
The researchers also found that most of the treatment effect of donepezil
occurred among APOE e4 allele carriers who appeared to have a reduced
risk for disease progression throughout the three years of the study.
David Taylor, chief pharmacist at the South London and Maudsley NHS Trust,
said this last finding was interesting. “There is a possibility
that people with mild cognitive impairment might be tested for the gene
and a decision made to treat with donepezil.” However, he pointed
out that it is unusual for people to present with mild cognitive impairment
and that most treatment occurs in patients with fairly advanced disease.
The study is published online in New
England Journal of Medicine.
Raloxifene A daily dose of 120mg raloxifene can reduce risk
of mild cognitive impairment by 33 per cent, trial data show. The
multiple
outcomes of raloxifene (MORE) trial involved 5,386 postmenopausal
women who received daily raloxifene (60mg or 120mg) or placebo.
Raloxifene 120mg/day also lowered the risk of Alzheimer’s
disease but this was not statistically significant. No significant
difference
in cognitive impairment was observed between the groups taking
60mg raloxifene
per day and placebo (American Journal of Psychiatry 2005;162:683).
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