Slimming injection may increase the risk of rare optic neuropathy, US FDA orders drug manufacturers to add warnings

The U.S. Food and Drug Administration (FDA) today requires popular weight loss and diabetes drugs such as Trixamethon and Menggen to carry warnings on their labels that they may increase the risk of optic neuropathy, which may lead to sudden vision loss or even permanent damage to vision.

Reuters reported that a large study published last year tracked nearly 350,000 diabetic patients, half of whom used the glucagon-like peptide-1 (GLP-1) drug semaglutide, and the other half used other diabetes drugs.

The study found that compared with other diabetes drugs, the risk of developing "non-arteritic anterior ischemic optic neuropathy" (NAION) after 2 years of treatment with GLP-1 drugs more than doubled.

The optic nerve is a bundle of fibers connected to the back of the eye, which transmits signals to the brain, allowing people to see. NAION is caused by reduced or blocked blood flow to the front of the optic nerve, causing sudden, painless vision loss. In some cases, vision may be permanently damaged, but the cause is still not fully understood.

The U.S. FDA stated that after comprehensive evaluation of clinical trial data, animal experiment data, post-marketing data, observational studies, case reports and other information, it has required pharmaceutical manufacturers that produce GLP-1 drugs to add relevant information in the "Warnings and Precautions" field of the package insert to indicate the possible increased risk of NAION.

The FDA pointed out that relevant drugs include Eli Lilly's Mounjaro and Zepbound, and Novo Nordisk's Ozempic and Wegovy.

A spokesman for Eli Lilly said: "The FDA's drug safety notification applies to all drugs with GLP-1 receptor agonist activity and does not mention any findings specific to Eli Lilly's products. We are carefully evaluating this latest information and will respond to the FDA as soon as possible."

A Novo Nordisk spokesman said: "Novo Nordisk still believes that the available data have not confirmed a causal relationship, and we remain highly confident in the benefit-risk assessment of our GLP-1 drugs."

Citi analyst Geoff Meacham pointed out: "This FDA measure may deepen the concerns of patients and investors in the short term. However, considering the rarity of NAION and the significant benefits of this type of drug in weight loss, blood sugar, cardiovascular, renal and sleep apnea, it should be able to maintain a good benefit-risk assessment and have a limited impact on physician prescriptions."

The Safety Committee of the European Medicines Agency (EMA) confirmed for the first time last year that among patients who have been using "semaglutide" for at least one year, up to 1 per 10,000 people may develop NAION. The Danish Patient Compensation also pointed out last year that 4 patients in Denmark developed symptoms of vision loss after using Novo Nordisk's GLP-1 drug and have received relevant compensation.