The UK’s health authorities have revised the product information for semaglutide treatments, alerting users to a very rare potential side effect known as NAION.
Semaglutide, a GLP-1RA medication, is designed to curb appetite and enhance insulin secretion. It is marketed under the names Rybelsus and Ozempic for type 2 diabetes management and Wegovy for weight loss.
Despite its numerous benefits, a 2024 study highlighted a potential risk involving vision loss among some patients.
Medical experts have indicated that semaglutide might lead to an ‘eye-stroke’ by blocking the arteries responsible for supplying blood to the eyes.
This adverse effect is exceedingly rare, with only three cases documented in the UK since the drug’s approval in 2018.
Nonetheless, authorities in other regions have revised their guidelines to reflect that non–arteritic anterior ischemic optic neuropathy (NAION) has been observed in some individuals using Wegovy.
NAION results from reduced blood circulation to the front portion of the optic nerve, potentially causing sudden, painless vision loss, typically in one eye.
Dr. Alison Cave, the Chief Safety Officer at The Medicines and Healthcare products Regulatory Agency (MHRA), commented: “Patient safety is the MHRA’s top priority and we continually monitor the safety and efficacy of all licensed medicines.
“While the potential risk of NAION for patients prescribed semaglutide is extremely small, it is important that patients and healthcare professionals are alert to the associated symptoms.”
Individuals taking semaglutide are advised to seek immediate medical attention if they notice ‘a sudden change in their eyesight’.
This includes experiencing ‘a sudden impairment to their vision, or if eyesight worsens rapidly in one or both eyes’, as stated by the MHRA.
Future semaglutide prescriptions will include a warning concerning the risk of vision loss.
Novo Nordisk, the company behind Ozempic and Wegovy, stated: “Patient safety is our top priority, and we take any reports about adverse events from the use of our medicines very seriously. We work closely with authorities and regulatory bodies from around the world to continuously monitor the safety profile of our products.
“The EU SmPC and patient leaflets for Wegovy, Ozempic (semaglutide injection), and Rybelsus (semaglutide tablets) have been updated to include ‘Non-arteritic anterior ischemic optic neuropathy (NAION)’ under section 4.4 ‘Special warnings and precautions for use’ and as an adverse drug reaction in section 4.8 ‘Undesirable effects’ (frequency: very rare, meaning it may affect up to 1 in 10,000 people taking semaglutide).
“Based on the totality of evidence we concluded that the data did not suggest a reasonable possibility of a causal relationship between semaglutide and NAION and Novo Nordisk believes that the benefit-risk profile of semaglutide remains favourable.”