• Posted February 14, 2022

Hints That Viagra-Like Drugs Might Help Prevent Dementia

Viagra-like drugs might do more than rejuvenate sex lives: A new study suggests that medications for erectile dysfunction may also help treat vascular dementia.

The medications are designed to increase blood flow to the penis in order to treat erectile dysfunction, so U.K. researchers decided to test whether one called tadalafil (Cialis) could also raise blood flow to the brain in older people with narrowing of the brain arteries. This narrowing can cause vascular dementia and strokes.

"Narrowing of the brain arteries is a common contributor to cognitive decline in older people and currently has no treatment," said principal investigator Dr. Jeremy Isaacs, a consulting neurologist at St. George's Hospital, University of London.

In the study, some participants received a single dose of tadalafil, while others got an inactive placebo. Their brain blood flow was recorded using a special type of MRI.

While there was no significant difference in brain blood flow between the two study groups, participants over 70 did show increased flow in the white matter of the brain, the area most important for vascular dementia, according to findings recently published in the journal Alzheimer's & Dementia.

Those findings from the phase 2 clinical trial suggest the value of further investigation into tadalafil's effectiveness in treating vascular dementia in older people, the researchers said.

"This was a landmark study in which we attempted to reverse the reduction in brain blood flow characteristic of this condition," Isaacs said in a St. George's news release. "Although we did not find a significant effect following a single dose of tadalafil, we can't rule out the possibility of benefits from longer-term use, for which further research is needed."

Tadalafil belongs to the same group of drugs as sildenafil (Viagra) and vardenafil (Levitra), which are also used to treat erectile dysfunction. Tadalafil was selected for this trial because it remains in the bloodstream for longer and there is evidence it is better able to enter the brain.

Lead investigator Dr. Atticus Hainsworth said Viagra-like drugs merit further investigation for possible use in dementia.

"Repurposed drugs have the increased benefits of a shorter development time, a known safety profile and low cost, once their original patent has expired," said Hainsworth, a reader in cerebrovascular disease at St. George's. "We hope that further investigations will prove fruitful and provide new options for clinicians treating dementia."

More information

There's more on vascular dementia at the U.S. National Institute on Aging.

SOURCE: St. George's, University of London, news release, Feb. 8, 2022