Doctors warn that patients taking unapproved peptide medications or GLP-1 injections like Ozempic must inform their anaesthetist prior to surgery to prevent serious complications, as new research links these drugs to increased regurgitation and aspiration risks.
Patients who are taking weight-loss injections or unapproved peptide drugs are being urged to tell their anaesthetist before surgery, after doctors warned that failing to do so could have “serious” consequences. The warning from the Australian and New Zealand College of Anaesthetists comes as concern grows that these drugs can leave food in the stomach for longer, raising the chance of regurgitation or pulmonary aspiration under anaesthetic.
Pulmonary aspiration happens when stomach contents enter the airway and lungs, where they can cause severe injury and, in some cases, death. ANZCA says some patients are still not disclosing use of GLP-1 medicines such as Ozempic and Mounjaro, or illegal peptides bought outside normal medical channels, because they forget, feel embarrassed or do not want to admit where the drugs came from. Tanya Selak, the college’s president, said some people worry they may be judged or treated differently if they reveal they are using the injections.
The warning follows a study published in the peer-reviewed journal Anaesthesia, which found that patients taking GLP-1 drugs were 11 times more likely to regurgitate or aspirate during general anaesthesia than those who were not using them. The research examined more than 47,000 patients in the UK and identified almost 1,350 who had been taking GLP-1 medicines for the three months before surgery. The authors said the association did not prove causation, noting that obesity and diabetes themselves can increase the risk of aspiration or regurgitation.
The findings have reignited debate over how best to manage patients on these medicines before surgery. ANZCA says people on GLP-1 drugs should have clear fluids for 24 hours before an operation, then fast for the standard six hours, while anaesthetists should specifically ask about these medicines. Similar advice has been issued in Britain by the Medicines and Healthcare products Regulatory Agency and endorsed by the Royal College of Anaesthetists, both of which say patients must disclose use of GLP-1 or dual GIP/GLP-1 drugs so their aspiration risk can be assessed individually. Michael Horowitz, a gastroenterology specialist at Adelaide University, has argued that blanket advice to stop the drugs a week before surgery is “demonstrably stupid”, saying delayed gastric emptying can persist and that more evidence is needed on how long it takes to normalise after treatment stops.
For Selak, the practical message is straightforward: patients should be open with their doctors about every medication they are using. She said the conversation is not about judgement but about making the safest plan possible for anaesthesia and surgery.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
