Study Finds Viagra and Cialis Do Not Reduce Alzheimer’s, Dementia Risk

WASHINGTON — Despite the results of a previous study, sildenafil (Viagra) and tadalafil (Cialis) may not be suitable candidates for treating dementia, according to the National Institutes of Health.
The institute recently delved into the situation with its Drug Repurposing for Effective Alzheimer’s Medicines study.
In the new study, NIH researchers and collaborators used data from Medicare beneficiaries and determined the medications sildenafil and tadalafil do not reduce the risk of Alzheimer’s disease and related dementias.
The study was funded by the NIH National Institute on Aging and results published in Brain Communications.
The NIA scientific team tested a class of drugs called phosphodiesterase-5 inhibitors. PDE5 inhibitors, of which sildenafil and tadalafil are examples, work by relaxing smooth muscle cells.
Sildenafil and tadalafil are U.S. Food and Drug Administration-approved treatments for erectile dysfunction and pulmonary atrial hypertension, a type of high blood pressure that affects the arteries in the lungs and the right side of the heart.
The scientists examined the risk of Alzheimer’s and related dementias using two groups of Medicare beneficiaries with PAH, those who were being treated with sildenafil or tadalafil, and those treated with another class of drugs.
They also tested whether sildenafil had effects on cell culture-based models of Alzheimer’s.
Results showed no reduced risk of Alzheimer’s and related dementias in patients treated with PDE5 inhibitors and no evidence that PDE5 inhibitors corrected molecular abnormalities associated with Alzheimer’s.