There is no cure for Alzheimer’s, but there are several treatments available that may impact disease progression or help address symptoms. Recently, researchers have been investigating whether drugs meant for other diseases may also be helpful for Alzheimer’s, and a new study finds that an insomnia medication may be a promising treatment possibility.
Recent research funded by the National Institutes of Health looked at the impact of dual orexin receptor antagonists, or DORAs, on Alzheimer’s symptoms. The reason it was thought that DORAs could help is that orexin, which helps people stay awake and is blocked by these drugs, has been linked with the development of Alzheimer’s. In mouse studies, blocking orexin with a DORA was also found to decrease levels of amyloid beta protein, an Alzheimer’s hallmark, in the brain. The findings of this current study, published in the journal Annals of Neurology, found that DORAs may help lower the levels of amyloid beta proteins in humans, as well.
The research involved 38 volunteers ranging in age from 45 to 65 who were cognitively healthy. They were split into three groups: One that received two higher doses of a DORA called suvorexant over 36 hours, one that received two lower doses of the drug, and one that received a placebo. Participants’ levels of amyloid beta and phosphorylated tau – also an Alzheimer’s hallmark that helps create tangles in the brain – were measured in cerebrospinal fluid afterward.
The team found that taking suvorexant didn’t impact the participants’ sleep, but in the morning, those who had received the higher dose had a 10 to 15% reduction in phosphorylation at a site on tau that contributes to tangles. Further, their levels of amyloid beta dropped 10 to 20% compared to the placebo group within 12 hours. However, within 24 hours, those levels had gone back up again, lowering, though, after the second dose.
The results indicate that DORAs could help protect cognitive health, though further study is needed to better understand this possible link.
Lead researcher Dr. Brendan Lucey from Washington University in St. Louis, explains, “We don’t yet know whether long-term use [of suvorexant] is effective in staving off cognitive decline, and if it is, at what dose and for whom. Still, these results are very encouraging. This drug is already available and proven safe, and now we have evidence that it affects the levels of proteins that are critical for driving Alzheimer’s disease.”
The team’s next step is a clinical trial to examine longer-term effects of orexin inhibitors on those at risk of developing dementia.
To read the whole study, click here.