Key Summary
- Korea’s Ministry of Food and Drug Safety said GLP-1 medicines used for obesity and diabetes may increase the risk of non-arteritic anterior ischemic optic neuropathy, or NAION.
- The agency distributed a drug safety letter to medical professionals and patients after reviewing overseas safety information.
- Among the products named in the source are Mounjaro, Wegovy, Saxenda and Epera.
- The ministry asked companies selling GLP-1 medicines in Korea to submit materials related to possible label changes and plans to revise usage precautions.
- The U.S. FDA had already asked manufacturers to add NAION risk information to prescribing details for the class.
Main Story
Korea’s drug safety authority has issued a warning about a potential vision-related side effect linked to GLP-1 class medicines used for obesity and diabetes treatment. The Ministry of Food and Drug Safety said it sent a safety communication to medical professionals and patients after reviewing overseas information indicating that these drugs could raise the risk of NAION, a condition that can cause sudden and painless vision loss.
According to the ministry, if NAION is suspected in a patient taking a GLP-1 medicine, medical professionals should stop administration and advise immediate medical evaluation. Patients were also told to contact their treating physician right away if related symptoms appear.
The medicines listed in the source include Mounjaro, whose active ingredient is tirzepatide, Wegovy with semaglutide, Saxenda with liraglutide, and Epera with epeglenatide.
In parallel with the safety notice, the ministry requested that pharmaceutical companies supplying GLP-1 drugs in the domestic market submit documents on the relevant safety information and any plans to change product approvals. The agency said it intends to review whether usage warnings and precautions should be revised on that basis.
The warning follows a move by the U.S. Food and Drug Administration, which on the 9th local time asked manufacturers to add a possible increased risk of NAION to the warning and precautions section of prescribing information for GLP-1 treatments. The FDA has been reviewing related safety data since a 2024 study raised a possible connection between semaglutide and NAION.
The source says the FDA analyzed data from 126 clinical trials involving a total of 134,253 people. In that analysis, NAION occurred at a rate of 6.4 cases per 100,000 person-years among users of GLP-1 drugs, compared with 3.8 cases among control groups given placebo or other blood sugar-lowering medicines.
NAION occurs when blood supply to the front part of the optic nerve is insufficient. Its typical symptoms include sudden loss of vision in one eye or partial blockage of the visual field without pain. The underlying cause has not yet been fully determined, and the condition can sometimes lead to permanent vision damage. It is also sometimes described as an “eye stroke.”
Background
The supplied source provides limited background beyond the FDA’s earlier review and the mention of a 2024 study that raised a link between semaglutide and NAION. No additional background was provided.
Items Requiring Further Verification
- The causal relationship between GLP-1 medicines and NAION has not been established in the supplied text; the article reports a possible increased risk based on safety reviews and studies.
- The precise mechanism by which these drugs might increase NAION risk remains unknown in the supplied text.
- The degree to which underlying conditions such as diabetes and high blood pressure contribute to NAION risk in individual cases is not determined in the supplied text.
- Any future label or precaution changes in Korea are described as planned review items, not finalized actions.