A new study led by UCL researchers suggests that drugs commonly used to treat erectile dysfunction may reduce the risk of Alzheimer’s disease.
Authors of new Neurology The study found that men who were prescribed erectile dysfunction drugs were 18% less likely to develop Alzheimer’s disease years later.
The study included 269,725 men who were diagnosed with erectile dysfunction and had no memory or thinking problems at the start of the study. Just over half (55%) were taking phosphodiesterase type 5 inhibitor medications, including sildenafil (sold as Viagra), tadalafil (Cialis), vardenafil, and avanafil, and were compared with those who had erectile dysfunction but were not prescribed the drugs.
Erectile dysfunction drugs work by dilating blood vessels and were originally developed to treat high blood pressure and angina. They act on a cell signaling messenger that has also been investigated for its links to memory. These drugs are able to cross the blood-brain barrier and can affect the activity of brain cells. Animal studies have found some neuroprotective benefits of phosphodiesterase type 5 inhibitors.
For the current study, based on prescription records, researchers found that men who were given erectile dysfunction medication were 18% less likely to later develop Alzheimer’s disease (after researchers adjusted the findings for potential confounding factors such as age, underlying health conditions), co-prescribed medication and smoking status), mean follow-up time was 5.1 years. This association was stronger among men who were issued the most prescriptions, suggesting that more regular use of the drug may have a greater impact on Alzheimer’s risk.
Among men prescribed erectile dysfunction medication, 749 were diagnosed with Alzheimer’s disease, corresponding to a rate of 8.1 cases per 10,000 person-years. Person-years represent both the number of people in the study and the amount each person spends in the study. Among men who were not given the drug, 370 developed Alzheimer’s disease, corresponding to 9.7 cases per 10,000 person-years.
While we are making progress with new Alzheimer’s disease treatments that work to clear amyloid plaques from the brains of people in the early stages of the disease, we desperately need treatments that can prevent or delay the development of Alzheimer’s disease.
More research is needed to confirm these results, learn more about the potential benefits and mechanisms of these drugs, and look at the optimal dosage. A randomized, controlled trial with both male and female participants is warranted to determine whether these findings also apply to women.”
Dr Ruth Brower, lead author, UCL School of Pharmacy
First author, PhD student Matthew Adesuyan (UCL School of Pharmacy) said: “While we cannot say based on our findings whether the drugs themselves reduced the risk of Alzheimer’s disease, the results are encouraging and may point to a new way of reducing Alzheimer’s. “Risk.”