The FDA’s order for a new vision loss warning on GLP-1s adds to a growing list of safety concerns and questions surrounding a drug class now used by millions. Here are seven issues clinicians, regulators and courts are working through:
- Vision loss. The FDA is requiring drugs including Mounjaro, Zepbound, Ozempic and Wegovy to add warnings about non-arteritic anterior ischemic optic neuropathy, a rare eye condition that can cause sudden, permanent vision loss in one eye. Novo Nordisk added a similar warning to European labels in June, saying the condition may occur in up to 1 in 10,000 patients. At least 4,000 consolidated claims allege GLP-1s caused vision loss, though drugmakers have disputed a causal link.
- Gastrointestinal injuries. The vision loss claims come amid a broader wave of consolidated lawsuits alleging GLP-1s caused gastrointestinal injuries such as gastroparesis and intestinal obstruction. Drugmakers have continued to defend the safety profiles of their products.
- Drug interactions. A case report linked tirzepatide to lithium toxicity in a woman with bipolar disorder, the fourth reported case. Her lithium level rose from 0.7 mmol/L to 1.2 mmol/L within three weeks of starting the drug, and an outside expert recommended checking lithium levels and kidney function during the first few weeks of treatment.
- Bone and joint risks. Two retrospective studies in March found associations between GLP-1 use and osteoporosis in some patients, including a 22% higher risk among users without diabetes who maintained a stable weight. The studies do not prove cause and effect, and one found an 8.7% lower risk among patients using the drugs for Type 2 diabetes.
- Illicit products. The FDA received reports that two people died after taking illicit products claiming to be Eli Lilly’s experimental drug retatrutide. The reports are unverified, and America’s Poison Centers logged 862 exposures to retatrutide in the three months ending in September, up from 460 in the previous three months.
- Compounded product quality. Apothecary Pharma is recalling 22 vials of compounded tirzepatide injection nationwide over a lack of assurance of sterility in a Class II recall.
- Pregnancy and breastfeeding. The American College of Obstetricians and Gynecologists advises against GLP-1 use during pregnancy because of a lack of safety data and recommends stopping the drugs one to two months before conception. Patients may be able to resume the drugs while breastfeeding with close monitoring of the infant but should avoid oral GLP-1s.
