Popular weight loss drugs such as Wegovy and Ozempic, are associated with an increased risk of stomach paralysis, pancreatitis and bowel obstruction, according to a study released Thursday out of the University of British Columbia.
The study, published in JAMA, found these adverse gastrointestinal effects happen in non-diabetic patients using the drugs specifically for weight loss.
Ozempic, Wegovy, Rybelsus and Saxenda are all medications used to treat Type 2 diabetes; however, they are also marketed as weight-loss drugs. The drugs — known as s known as GLP-1 agonists — work by triggering insulin release, blocking sugar production in your liver, and making you feel full. Health Canada has approved all four drugs for the treatment of diabetes.
The UBC researchers found that when people take these drugs strictly for weight loss, it can cause a serious risk of medical conditions.
“There have been anecdotal reports of some patients using these drugs for weight loss and then presenting with repeated episodes of nausea and vomiting secondary to a condition referred to as gastroparesis,” senior author Dr. Mahyar Etminan, an epidemiologist and associate professor in the department of ophthalmology and visual sciences at the UBC faculty of medicine, said.
“But until now, there hasn’t been any data from large epidemiologic studies,” he said in a Thursday media release.
To figure out whether there was a link between these weight loss drugs and issues like stomach paralysis, the researchers looked at health insurance claim records of around 16 million patients in the United States. They then examined prescriptions of the two main GLP-1 agonists — semaglutide (Ozempic) or liraglutide (Saxenda) — between 2006 and 2020. They also included patients with a recent history of obesity, but excluded those with diabetes or who had been prescribed another antidiabetic drug.
The researchers checked the patient’s medical records to see how many developed four different stomach-related problems: pancreatitis, bowel obstruction, gastroparesis (stomach paralysis) and biliary disease (a group of conditions affecting the gall bladder).
They then compared the rate of patients using GLP-agonists versus another weight loss drug called bupropion-naltrexone.
Compared to bupropion-naltrexone, patients on GLP-1 agonists medication had nine times higher risk of pancreatitis (inflammation of the pancreas), four times higher risk of bowel obstruction (food is prevented from passing through the small intestine) and three times higher risk of stomach paralysis. The latter condition limits the passage of food from the stomach to the small intestines and results in symptoms like vomiting, nausea and abdominal pain.
There was also a higher risk of incidence of biliary disease, but the researchers said it was not “statistically significant.”
Although these side effects are rare, the study’s authors said because millions of people around the world use the drugs, “it could lead to hundreds of thousands of people experiencing these conditions.”
The exact number of Canadians using these weight loss drugs is not known, but Ozempic has become so popular that in August, its manufacturer, Novo Nordisk, announced a shortage of the medication in Canada.
“These drugs are becoming increasingly accessible, and it is concerning that, in some cases, people can simply go online and order these kinds of medications when they may not have a full understanding of what could potentially happen. This goes directly against the mantra of informed consent,” Sodhi said in the media release at the time.
The researchers said they hope the drug makers of GLP-1 agonists will consider updating the warning labels of their products, which currently don’t include the risk of gastroparesis.
In 2018, Health Canada approved Ozempic as a medication to treat people with diabetes, but not for weight loss.
Wegovy, a higher dose version of the same drug, was approved for weight loss in 2021 in Canada but has never been sold here due to high global demand and supply shortages.
Health Canada approved Rybelsus in 2020 as a medication to treat diabetes but not weight loss. And Saxenda was approved for weight loss in 2015.
Ozempic and stomach paralysis
The UBC research is the first epidemiological study that links popular weight loss drugs to stomach paralysis and other serious gastrointestinal conditions.
Prior to that, there were anecdotal accounts, one of which Global News reported on Aug. 3, 2023.
Emily Wright, a Toronto elementary school teacher, started taking the drug Ozempic in 2018 as a way to control her food cravings and blood sugar in her battle with Type 2 diabetes.
She began losing weight, but at the same time, she started experiencing constant vomiting, lingering nausea, and what she described as “terrible-smelling sulfur burps resembling the odor of rotten eggs.”
“The doctor said those side effects would eventually go away. As I started to lose weight, I remained on Ozempic, and within one year I was able to lose over 80 pounds,” Wright previously told Global News.
But her symptoms worsened. Two years later she was hospitalized for severe nausea and dehydration as she could not stop vomiting.
“I was treated for dehydration or what they call ‘cyclic vomiting-like symptoms,’” Wright said, adding she was diagnosed with gastroparesis, which causes stomach paralysis.
A doctor believed Ozempic may be connected to her symptoms, and requested she stop taking it.
Since going off the drug, she said her symptoms have not improved and has had to take a leave of absence from her job.
She said she doesn’t know if Ozempic caused her condition, but believes it may have exacerbated it.
“I’m on medication, which I will likely have to be on for the rest of my life to speed up the motility of my stomach, as well as daily nausea medication to combat vomiting,” Wright said. “Ultimately, this helps me to be able to stay out of the hospital.”
Dr. Ravi Retnakaran, an endocrinologist and professor of medicine at the University of Toronto, previously told Global News in August that although nausea is one of the most common side effects of Ozempic (and all other medications in this drug class), a severe reaction such as Wright’s is very rare.
“The GI side effects, they are real. A lot of people will get them, but generally, they’re not going to cause people to be unable to take the medication,” he said. “There is, of course, a subset of patients in whom that occurs. The nausea is too much, and they can’t take it.”
In an email to Global News in August, a spokesperson from Novo Nordisk, the creator of Ozempic, said, “Patient safety is of utmost importance to Novo Nordisk, and we take all reports about adverse events from use of our medicines very seriously.”
Gastrointestinal events are well-known side effects of the GLP-1 class, explained Kate Hanna, the spokesperson for Novo Nordisk’s Canadian arm.
“For semaglutide, the majority of GI side effects are mild to moderate in severity and of short duration. GLP-1s are known to cause a delay in gastric emptying,” she said.
“While diabetes is a well-known risk factor, there are other risk factors that may increase the risk of gastroparesis such as obesity, gender (female), virus infection and nervous systems disease.”
