(Bloomberg) — European health authorities said patients due to undergo surgery should be warned of a risk of anesthesia complications if they’re being treated with diabetes and weight-loss drugs from Novo Nordisk A/S and Eli Lilly & Co.

The safety committee of the European Medicines Agency advised patients treated with GLP-1 drugs to inform their doctor before undergoing surgeries with general anesthesia or deep sedation and said product information will be updated accordingly. There is a “biologically plausible risk” of aspiration of stomach contents for patients under anesthesia and taking such medication, the agency said, even though it didn’t find a “causal association.”

The updated guidance comes after the EU last year requested more information from four companies, including Novo and Eli Lilly, about possible anesthesia complications. GLP-1 drugs include Novo’s Wegovy and Ozempic, as well as Lilly’s Mounjaro. 

The American Society of Anesthesiologists also issued guidance in June 2023 to suggest patients skip a dose of the drugs prior to surgery. 

The potential risk occurs because the drugs delay the emptying of the stomach, creating the possibility of food remaining even if patients observe a fasting period before surgery. Fluid from the stomach entering the lungs can put patients at risk of developing pneumonia. 

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