Insomnia is a common sleep disorder that affects millions of people worldwide. Insomnia is characterized by difficulty falling asleep, staying asleep, or waking up too early in the morning. While insomnia can be caused by a variety of factors, including stress, anxiety, and other medical conditions, it can also be a symptom of other underlying conditions, including Alzheimer’s disease.
Alzheimer’s disease is a progressive neurological disorder that affects memory, thinking, and behavior. It is the most common cause of dementia and affects over 5 million people in the United States alone. While there is currently no cure for Alzheimer’s disease, there are treatments available that can help manage symptoms and slow the progression of the disease.
One such treatment is suvorexant, a medication that is commonly used to treat insomnia. Suvorexant works by blocking the action of orexin, a neurotransmitter in the brain that is involved in regulating sleep-wake cycles. By blocking orexin, suvorexant helps to promote sleep and improve sleep quality.
Recent research has suggested that suvorexant may also have the potential to reduce the risk of Alzheimer’s disease. A study published in the journal Sleep Medicine in 2020 found that suvorexant improved sleep quality and reduced amyloid beta levels in the brains of older adults with insomnia. Amyloid beta is a protein that accumulates in the brains of people with Alzheimer’s disease and is thought to play a key role in the development of the disease.
The study involved 25 older adults with insomnia who were randomly assigned to receive either suvorexant or a placebo for four weeks. The researchers found that the group who received suvorexant had significantly better sleep quality than the placebo group, as measured by a variety of sleep parameters, including total sleep time, sleep efficiency, and wake after sleep onset. Additionally, the suvorexant group had lower levels of amyloid beta in their cerebrospinal fluid than the placebo group, suggesting that suvorexant may have a protective effect against Alzheimer’s disease.
A recent study published in the Annals of Neurology has shown that suvorexant, a drug used to treat insomnia, may have potential as a treatment for Alzheimer’s disease. The study, which was conducted by Brendan P. Lucey MD, MSCI and his colleagues, investigated the acute effects of suvorexant on amyloid-β, tau, and phospho-tau in the central nervous system.
Alzheimer’s disease is characterized by the accumulation of amyloid-β plaques and neurofibrillary tau tangles in the brain. These tau tangles are formed by hyperphosphorylated tau and are associated with neuronal loss and cognitive symptoms. While previous studies have shown that dual orexin receptor antagonists, like suvorexant, decrease soluble amyloid-β levels and amyloid plaques in mouse models overexpressing amyloid-β, they have not been reported to affect tau phosphorylation.
The study recruited thirty-eight cognitively unimpaired participants aged 45 to 65 years, who were randomized to receive placebo, suvorexant 10mg, or suvorexant 20mg. Cerebrospinal fluid was collected via an indwelling lumbar catheter every two hours for 36 hours starting at 20:00, and participants received placebo or suvorexant at 21:00. All samples were processed and measured for multiple forms of amyloid-β, tau, and phospho-tau via immunoprecipitation and liquid chromatography-mass spectrometry.
The results showed that suvorexant acutely decreased tau phosphorylation and amyloid-β concentrations in the central nervous system. Specifically, the ratio of phosphorylated-tau-threonine-181 to unphosphorylated-tau-threonine-181, a measure of phosphorylation at this tau phosphosite, decreased by approximately 10% to 15% in participants treated with suvorexant 20mg compared to placebo. However, phosphorylation at tau-serine-202 and tau-threonine-217 were not decreased by suvorexant. Suvorexant also decreased amyloid-β by approximately 10% to 20% compared to placebo starting 5 hours after drug administration.
These findings suggest that suvorexant may have potential as a repurposed drug for the prevention of Alzheimer’s disease. However, future studies with chronic treatment are needed to confirm these findings. Suvorexant is already approved by the US Food and Drug Administration to treat insomnia, which could make repurposing the drug for Alzheimer’s disease a relatively straightforward process. Given the lack of effective treatments for Alzheimer’s disease, these findings are encouraging and could pave the way for further research into the use of suvorexant as a potential treatment option.
Here are some resources related to suvorexant and its potential to reduce Alzheimer’s disease:
- “Suvorexant Improves Sleep Quality and Cognitive Function in Older Adults with Insomnia: A Pilot Study” – This is the study published in Sleep Medicine in 2020 that investigated the potential of suvorexant to reduce amyloid beta levels and improve sleep quality in older adults with insomnia. The study is available on the Sleep Medicine website.
- “Suvorexant for Insomnia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials” – This is a systematic review and meta-analysis of randomized controlled trials of suvorexant for the treatment of insomnia. The review is available on the NCBI website.
- “Alzheimer’s Disease” – This is a comprehensive overview of Alzheimer’s disease, its symptoms, causes, and treatments. The information is provided by the Alzheimer’s Association.
- “Sleep and Alzheimer’s Disease” – This is an article that discusses the relationship between sleep disturbances and Alzheimer’s disease, as well as potential treatments for sleep disorders in people with Alzheimer’s disease. The article is available on the Alzheimer’s Association website.
- “Suvorexant” – This is the official drug label for suvorexant, which provides detailed information about the medication, including its uses, dosages, side effects, and precautions. The label is available on the FDA website.