US regulator orders makers of weight-loss drugs to carry blindness risk warning

The U.S. Food and Drug Administration is requiring manufacturers of all GLP-1 drugs to update their prescribing information with a warning about the potential risk of non-arteritic anterior ischemic optic neuropathy (NAION), a rare but potentially blinding eye condition, MedPage Today reported. The warning applies to drugs including Eli Lilly's Mounjaro and Zepbound, and Novo Nordisk's Ozempic and Wegovy, according to CNN.

Cases of NAION have been documented across all currently marketed GLP-1 products, MedPage Today said. The FDA's action follows studies suggesting a potential link between GLP-1 drugs and NAION, including a 2024 JAMA Ophthalmology study involving semaglutide that prompted the agency's review. Europe's drug regulator warned about the risk 17 months ago.

In an FDA meta-analysis of randomized trials, 15 probable NAION events were identified among more than 134,000 patients. Ten cases occurred among roughly 78,000 patients treated with GLP-1 drugs, none occurred among those randomized to other glucose-lowering medications, and five occurred in placebo recipients. Incidence was 6.4 cases per 100,000 person-years among GLP-1 drug recipients compared with 3.8 cases per 100,000 person-years among patients receiving a non-GLP-1 medication or placebo.

Healthcare providers should instruct patients to immediately report sudden onset of acute, painless, decreased vision, visual field deficits, or other visual disturbances in one eye, the FDA stated in a safety communication on Monday. If NAION is suspected, patients should be promptly referred to an ophthalmologist, and clinicians should consider discontinuing the GLP-1 receptor agonist unless the benefits clearly outweigh the risk.

Novo Nordisk said it continues to believe the data do not establish a cause-and-effect relationship and remains confident in the benefit-risk profile of its GLP-1 medicines, CNN reported. Eli Lilly said it is carefully evaluating the update and will respond to the FDA promptly. Patients and clinicians can report suspected adverse reactions to the FDA's MedWatch reporting program.