A new study has found that the antiviral drug valacyclovir, which is commonly used to treat herpes infections, did not help people with early-stage Alzheimer’s disease.
In fact, people who took the drug showed more cognitive decline than those who were given a placebo. The results come from researchers at the New York State Psychiatric Institute, Columbia University Medical Center, and other research centers across the U.S., and were published in the journal JAMA.
Some scientists have suspected that viruses like herpes simplex virus (HSV) might play a role in causing or worsening Alzheimer’s disease. HSV-1 is a common virus that can stay in the body for life, and some studies have found traces of it in the brains of people who had Alzheimer’s.
Lab experiments on cells and animals showed that certain antiviral drugs could reduce levels of amyloid beta and tau—proteins that are linked to Alzheimer’s. Because valacyclovir is a well-known antiviral drug used to treat HSV, researchers wanted to test whether it could help slow the disease in humans.
The study included 120 adults who had early symptoms of Alzheimer’s disease and tested positive for HSV-1 or HSV-2 antibodies, meaning they had been exposed to the virus.
They also had Alzheimer’s biomarkers and Mini-Mental State Exam (MMSE) scores between 18 and 28, suggesting mild cognitive impairment. Half of the group took 4 grams of valacyclovir each day, while the other half took a placebo. The study lasted for 78 weeks, or about a year and a half.
To keep the study fair, neither the patients nor the researchers knew who was receiving the real drug and who was getting the placebo. Capsules looked the same, and treatments were sent by mail to each participant. Some participants also had brain scans and gave samples of spinal fluid to help track how the drug affected the brain.
Unfortunately, the results were disappointing. People in both groups got worse over time, but those taking valacyclovir got worse faster. Their scores on a cognitive test called the Alzheimer’s Disease Assessment Scale went up by nearly 11 points, meaning their thinking and memory worsened.
The placebo group’s scores went up by only 7 points. On a daily living skills test, both groups also declined, but the difference between them was not statistically significant. Brain scans did not show any major differences between the two groups in terms of amyloid or tau buildup.
The researchers were surprised by the results. They had hoped valacyclovir might slow the progression of Alzheimer’s or at least have no effect. Instead, the study suggests it may make things worse. The exact reason why this happened is still unknown. The authors concluded that valacyclovir should not be used to treat Alzheimer’s in patients who have HSV.
This study shows the importance of testing even familiar medications in clinical trials before using them for new conditions. While lab studies can show promise, they don’t always work out in real patients. More research is needed to better understand the links between infections like HSV and brain diseases like Alzheimer’s.
If you care about Alzheimer’s disease, please read studies about root cause of Alzheimer’s disease and new treatment and Scientists find the link between eye disease glaucoma and Alzheimer’s disease.
For more health information, please read studies about new way to treat Alzheimer’s disease and Fluctuating cholesterol and triglyceride levels are linked to Alzheimer’s disease.
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