Medical Forum
Safety warning: GLP-1s linked to serious eye disorder
A class-wide safety update has been issued for GLP-1 RA medications after they were linked to a rare but severe eye problem.
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Medical Forum
The Therapeutic Goods Administration (TGA) warned the medicines, commonly used to treat diabetes and obesity, had the potential to cause non-arteritic anterior ischaemic optic neuropathy (NAION).
The condition is caused by compromised blood flow to the optic disc and can lead to permanent visual impairment, including blindness.
The medicines regulator urged health professionals prescribing these medications, or managing patients on these medications, to be alert for sudden vision changes.
Patients should be advised to seek urgent medical help if they experience sudden vision loss or changes.
The safety warning applies to products containing semaglutide (sold as Ozempic and Wegovy), dulaglutide (sold as Trulicity), tirzepatide (Mounjaro) and liraglutide (Saxenda).
The warning follows a number of adverse events reported to the regulator and a study published in JAMA Ophthalmology which found a potential increased risk of NAION in patients prescribed semaglutide.
The Database of Adverse Event Notifications show 36 cases of optic ischaemic neuropathy with GLP-1 RAs. Some 23 were linked to semaglutide, three to liraglutide and 10 to tirzepatide.
No cases were found for dulaglutide, though one semaglutide case had a history of prior dulaglutide use.
The TGA said it first became aware of the potential risk following the study in July 2024.
“Since then, the association has been closely monitored including through analysis of Australian cases reported to us, and investigations and regulatory actions by overseas regulators,” it said in a statement.
Perth GP and WA lead for the RACGP obesity special interest group Dr Mark Mellor said that while the risk did need to be considered, it also needs to be balanced with the benefits that GLP-1 agonists have for many patients with diseases like obesity and diabetes.
“This is a rare condition, but it can cause permanent vision loss in some cases, so it’s a significant risk that we need to consider with our patients.
“There is still no clear guidance on whether we should screen patients before they go onto these medicines to look for signs at the back of the eye, because that might increase the risk.
“It is important doctors advise patients that this is a risk, but the risk is generally small. If we have a patient that mentions that historically they have had optic neuritis or other eye problems, then it enables us to refer the patient to an ophthalmologist.”
Patients who might be at a higher risk of developing NAION include those who have a crowded optic disc, and also those who are older – most cases occur in adults 50 years and above – people who have diabetes, high blood pressure, high cholesterol, obstructive sleep apnoea and smokers.
“These are important factors we consider when taking a patient’s history,” Dr Mellor said.
“But this is the cohort of patients we tend to see who are seeking these medications because they are living with obesity.”
It is not the first time a safety warning has been linked to GLP-1 medications.
Late last year, the TGA warned that the drugs could lead to potential suicidal thoughts, while another study also suggested the medications could reduce the effectiveness of oral contraceptives.
Earlier this year, concerns were raised that the drugs could put users at risk of serious nutritional deficiencies. University of Newcastle researchers said this could lead to higher risk of heart issues, chronic diseases and some cancers due to inadequate nutrition.