Health Canada Approves Zepbound for Treating Obstructive Sleep Apnea in Adults With Obesity
Health Canada has approved the weight-loss drug Zepbound for the treatment of obstructive sleep apnea in adults living with obesity, marking a significant milestone in the management of the sleep disorder. The approval, granted on June 11, makes Zepbound the first and only GLP-1 receptor agonist approved in Canada specifically for this condition.
How Obstructive Sleep Apnea Affects the Body
Obstructive sleep apnea is a disorder in which people temporarily stop breathing during sleep because their upper airways become blocked. This blockage can occur when the throat muscles relax excessively or when there is an excess of fatty tissue around the upper airway. The condition frequently leads to daytime sleepiness and carries serious health risks, including high blood pressure, heart attacks, and strokes.
Dr. Mandeep Singh, a clinical researcher in sleep sciences at the University Health Network in Toronto, noted that the disorder is often associated with obesity and can be improved through weight loss. The severity of obstructive sleep apnea is measured by the number of breathing pauses per hour of sleep. People with mild sleep apnea typically experience five to 14 interruptions per hour, those with moderate cases have 15 to 30, and patients with severe sleep apnea experience more than 30 interruptions per hour.
The Active Ingredient: Tirzepatide
The active ingredient in Zepbound is tirzepatide, a medication that acts on two hormone receptors — GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) — to reduce appetite, which in turn leads to weight loss. Zepbound, manufactured by Eli Lilly, is a competitor to Novo Nordisk’s semaglutide drugs Ozempic and Wegovy. Eli Lilly’s tirzepatide portfolio also includes the diabetes drug Mounjaro.
Clinical Trial Results Show Significant Improvement
Health Canada’s approval was based on results from Phase 3 clinical trials involving patients who suffered from both obesity and sleep apnea. The findings were striking. Among patients who did not use a continuous positive airway pressure (CPAP) machine, those taking tirzepatide experienced 25 fewer breathing interruptions per hour compared to five fewer in the placebo group. In patients who did use a CPAP machine, those on tirzepatide saw 29 fewer breathing interruptions per hour compared to six fewer among those on a placebo.
Dr. Singh, who was not involved in the clinical trials, emphasized the clinical significance of these results. “A reduction of 25 to 29 events per hour would represent a significant change, potentially moving someone from a severe to a lower severity category, depending on where they started,” he said.
Not a Replacement for CPAP, but a Welcome New Option
Health Canada spokesperson Marie-Pier Burelle clarified that Zepbound is “not an immediate replacement” for CPAP therapy, which remains the first-line treatment for moderate to severe sleep apnea. She advised that patients taking Zepbound should not discontinue use of their CPAP machine without consulting their healthcare provider.
The drug is intended to be injected once a week and should be used alongside a reduced-calorie diet and increased physical activity in adults with a body mass index (BMI) of 30 kg/m² or higher.
Dr. Singh expressed optimism about the approval. “I think this is a welcome step to offer patients with obstructive sleep apnea another option,” he said. He added that whenever a patient is diagnosed with the condition, clinicians discuss the risks and benefits of all available treatment options, and this medication will now be included in those conversations.
Side Effects and the Need for Further Research
As with other GLP-1 medications, the most common side effects of tirzepatide include nausea, vomiting, diarrhea, and constipation. More serious but much less likely side effects include inflammation of the pancreas, intestinal obstruction, and gallstones.
Dr. Singh also noted that while there is anecdotal evidence from doctors suggesting that weight loss achieved with other GLP-1 medications may benefit people with sleep apnea, formal research confirming this is still lacking. He highlighted the need for additional studies to determine whether tirzepatide might have a direct effect on sleep apnea in patients who do not have obesity.
“If we can somehow figure out what the effects of weight loss are compared to the direct effects of these drugs on the upper respiratory tract, that will be very interesting,” he said.
