Higher risk reduction was seen in men who were issued more than 20 prescriptions over the study period
In a new study, men who took phosphodiesterase type 5 inhibitors (PDE5Is), such as Viagra (sildenafil; Pfizer), for treatment of erectile dysfunction, were found to be 18 per cent less likely to develop Alzheimer’s compared to those who did not take the drugs.
The results of the population-based cohort study were published in Neurology on 7 February 2024.
Researchers at University of Oxford examined IQVIA Medical Research Data UK records of 269,725 men, who were diagnosed with erectile dysfunction between January 2000 and March 2017.
None of the participants had any memory or thinking problems at the start of the study and they were followed for an average of 5.1 years.
During the study, 749 out of 1,119 participants taking erectile dysfunction drugs developed Alzheimer’s disease.
According to the authors, this was equivalent to a rate of 8.1 cases per 10,000 person years, as against 9.7 cases per 10,000 person years recorded in men who did not take the drugs.
Moreover, the associated risk of Alzheimer’s was found to be lower in men who were issued more than 20 prescriptions over the study period.
Ivan Koychev, senior clinical researcher at Dementias Platform UK, University of Oxford, suggested that the risk appeared to be dose dependent, meaning higher risk reduction with more prescriptions.
As the results were more pronounced in people with risk factors of heart disease (high blood pressure, diabetes), Koychev assumed that the effect may be due to “neuroprotection through vascular mechanisms.”
He added that although the study has limitations, it is a significant development as “repurposing already-existing drugs for the prevention of dementia is a promising strategy to stop dementia from developing in the first place.”
Alzheimer’s disease is estimated to account for approximately 50–75 per cent of dementia cases in the UK.
Sadly, there is no cure for the disease, but there are treatments, such as monoclonal antibodies, that can help to delay its progression.