Viagra-like sex drug also effective as HF therapy

Research out of the University of Manchester suggests Tadalafil (Cialis)—an erectile dysfunction drug that falls in the same class as Viagra—could slow and possibly reverse the progression of heart failure (HF).

Senior author Andrew Trafford, PhD, a professor of cardiac pathophysiology at Manchester, and colleagues conducted their experimental study in sheep, but Trafford said that since sheep’s hearts are so similar to humans’, his team’s findings will likely also translate to people.

In Scientific Reports, where the authors published their findings May 1, the authors said there’s existing, albeit limited, evidence from human trials and epidemiological studies showing that Tadalafil might hold promise as a therapy for heart failure. To test the idea, they used pacemakers to induce HF in a cohort of sheep, which, once their condition was advanced enough to require treatment, were given a dose of Tadalafil comparable to that a human male would take to treat erectile dysfunction.

“Viagra-type drugs were initially developed as potential treatments for heart disease before they were found to have unexpected benefits in the treatment of erectile dysfunction,” Metin Avkiran, associate medical director at the British Heart Foundation, said in a release. The Foundation funded Trafford and colleagues’ research.

“We seem to have gone full-circle, with findings from recent studies suggesting that they may be effective in the treatment of some forms of heart disease.”

According to information from the U.S. National Library of Medicine, Tadalafil isn’t only used to treat impotence—it’s also an approved therapy for easing the symptoms of benign prostatic hyperplasia and is used to improve the ability to exercise in patients with pulmonary arterial hypertension (PAH). The drug treats PAH by relaxing the blood vessels in the lungs, allowing blood to flow more easily.

Trafford and co-authors hoped it would have a similar effect in HF patients. Within a short period of administering Tadalafil to the study sheep, the team found the animals’ conditions stopped worsening, and the drug eventually reversed the effects of HF. It also seemed to improve patients’ hearts’ responses to adrenaline.

“This study provides further confirmation, adds mechanistic details and demonstrates that Tadalafil can be effective in treating heart failure,” Trafford said in the release. “It’s entirely possible that some patients taking it for erectile dysfunction have also unwittingly enjoyed a protective effect on their heart.”

Trafford noted Tadalafil is “a widely used and very safe” drug with few serious side effects, but said he advises patients speak with their physicians before attempting to self-treat with it.

“Tadalafil is only suitable as a treatment for systolic heart failure—when the heart is not able to pump properly—and there may be interactions with other drugs patients are taking,” he said.