Feeling faint? Researcher discovers new use for older drug to reduce fainting episodes

About 40 per cent of Canadians will faint at some point during their life due to a drop in blood pressure and at times because of a slower heart rate.

When fainting occurs with a specific trigger, like the sight of blood, when standing too long or becoming overheated, or in response to intense activity or emotion such as fear, it is called vasovagal syncope.

Vasovagal syncope is the most common cause of fainting, affecting more than one-third of us at some point, but some people faint multiple times each year, which impacts their quality of life and puts them at risk of injury.

Dr. Robert Sheldon, MD, a cardiologist and researcher at the Cumming School of Medicine, is internationally respected for his knowledge of syncope. He says about half the patients he sees in his clinic suffer from vasovagal syncope. For many patients, the condition can be very troublesome.

“With each faint, you have a 15 per cent chance of injury,” says Sheldon. “There is also a lot of depression and anxiety in individuals who faint frequently, and their quality of life is heavily impacted.”

Sheldon is working to improve the quality of life for individuals with the condition.  

International study finds new use for older drug

His multi-year, international study, Midodrine for the Prevention of Vasovagal Syncope, was recently published in the journal Annals of Internal Medicine. The study found a new use for an older drug, Midodrine, used to treat light-headedness in older patients, is very effective in preventing fainting episodes, especially in young, otherwise healthy people.

The randomized phase three trial followed 133 individuals who faint six times a year on average. Study participants were prescribed either a placebo or Midodrine and followed for one year.

Proving the efficacy of the drug in treating vasovagal syncope is good news for Sheldon, who has been conducting clinical trials looking at ways to treat the condition for more than a decade.  

“Midodrine is the only treatment we have found that achieved a strongly positive outcome,” says Sheldon, noting it will be the standard of care for this demographic. “It fills a need for these patients.”

Libin Cardiovascular Institute Director Paul Fedak says Sheldon has reached the highest bar of evidence with his world-class clinical randomized trial.

“Repurposing existing medications for challenging clinical problems facilitates immediate use in clinical practice, and this exciting discovery can be used without delay for many people with few other options,” says Fedak. “This will capture the attention of the world."

This project was funded by the Canadian Institutes for Health Research.