Doctors are warning that millions of Canadians are taking a commonly prescribed class of drugs used to treat acid reflux much longer than the recommended two-month period, upping the risk of a number of health-related side-effects.

Proton pump inhibitors, as the class of drugs is known, are found in medicine cabinets across Canada. They reduce the production of stomach acid, which helps break down food but can reflux up the throat and cause a burning sensation or severe discomfort.

The drugs’ efficacy is the reason they are the second-most commonly prescribed medication in Canada. Product monographs say that doctors should prescribe the lowest dose for the shortest amount of time possible, and no longer than eight weeks.

Susan Tucker, of Charlottetown, was prescribed one of the drugs to treat severe acid reflux in 2014. At first, the drug worked and eliminated her symptoms, but one year later, she was surprised to learn that she had suddenly developed kidney disease.

“It took me a year-and-a-half to see a specialist and it was the first thing he said of the pump inhibitor was that it was probably, most likely the cause of it,” said Tucker.

Dr. Kimberly Wintemute, a primary care doctor in Toronto, has seen patients who never get off of them. A small subset of people, including those with severe esophagitis, may need to take them longer term, but that is often not the case for those who began taking them for acid reflux, she said.

“It just gets refilled, refilled, refilled and before long, you get a situation where someone has been on them for one year or two or three,” she said.

Canadian seniors, in particular, are using them inappropriately, with up to 70 per cent taking them over a long-term period, various studies say. Proton pump inhibitors are the second-most commonly prescribed drug class among Canadian seniors, according to the Canadian Institute for Health Information. The rates of chronic proton pump inhibitors among seniors are higher than 30 per cent in Newfoundland, New Brunswick and Quebec, while British Columbia, Manitoba and the Yukon have rates below 20 per cent.

Wintemute is part of a group of doctors with Choosing Wisely Canada, which is calling for the careful use of drugs for acid reflux.

“The goal is not to get everyone off medication,” said Wintermute. “The goal is to identify people who don’t need it anymore or who aren’t benefiting anymore.”

The side-effects associated with taking proton pump inhibitors over the long-term include an increased risk of bone fractures, an inability to absorb nutrients, kidney damage, stomach infections and even a higher risk of dementia.

“A lot of the work we’re trying to do is raise awareness at a public level to say, ‘Should you still be on this medication? Go and talk to your pharmacist or physicians and reevaluate your need for it,’” said Justin Turner, a senior science advisor for science strategy at the Canadian Deprescribing Network in Montreal.

The group, which is focused on helping patients get off a variety of unnecessary medications, launched a pilot program in Newfoundland called SaferMedsNL. It hopes to expand the campaign across the country.

But some physicians are already taking the message to heart.

In Toronto, Wintermute has tried flagging patients on the drugs for longer than recommended, probing whether they need to be on them. The end result is that she has managed to get 26 per cent of those patients off of the medications -- a result she describes as “deeply gratifying.”

“You don’t want your patients taking risks, you know, that they don’t need to take,” she said.

The long-term use of the drugs also puts a strain on the health care system. Many of the medications prescribed to seniors are covered by provincial drug plans. Then, there is the risk that complications from taking the drugs, such as C. difficile infections or Tucker’s kidney damage, will require extended hospital stays.

As soon as Tucker went off the drugs, her kidney condition stabilized.

“This may not happen to you, but if you are going to take a pump inhibitor, the doctors need to be aware, the public needs to be aware,” she said.

Even effective medications can be overused, Tucker said.

Wintermute said that other medications with less dangerous side-effects can be prescribed to treat acid reflux and that making lifestyle or diet changes can often help alleviate symptoms.

Patients should always consult with their doctors or pharmacists before deciding to stop taking the medication.

To prevent heartburn without a proton pump inhibitor, experts recommend trying to figure out which foods or beverages trigger acid reflux and to avoid them. Some common foods and beverages known to cause acid reflux are fried or spicy foods, alcohol, garlic, onions and chocolate.

Eating smaller meals, losing weight, avoiding tight clothing, quitting smoking and avoiding eating before bed may also alleviate symptoms.

---- writer Amanda Coletta also contributed to this story