Patients are overdosing on compounded semaglutide due to errors in measuring and self-administering the drug and due to clinicians miscalculating doses that may differ from US Food and Drug Administration (FDA)–approved products.
The FDA published an alert on July 26 after receiving reports of dosing errors involving compounded semaglutide injectable products dispensed in multidose vials. Adverse events included gastrointestinal effects, fainting, dehydration, headache, gallstones, and acute pancreatitis. Some patients required hospitalization.
Why the Risks?
FDA-approved semaglutide injectable products are dosed in milligrams, have standard concentrations, and are currently only available in prefilled pens.
Compounded semaglutide products may differ from approved products in ways that contribute to potential errors — for example, in multidose vials and prefilled syringes. In addition, product concentrations may vary depending on the compounder, and even a single compounder may offer multiple concentrations of semaglutide.
Instructions for a compounded drug, if provided, may tell users to administer semaglutide injections in “units,” the volume of which may vary depending on the concentration — rather than in milligrams. In some instances, patients received syringes significantly larger than the prescribed volume.
Common Errors
The FDA has received reports related to patients mistakenly taking more than the prescribed dose from a multidose vial — sometimes 5-20 times more than the intended dose.
Several reports described clinicians incorrectly calculating the intended dose when converting from milligrams to units or milliliters. In one case, a patient couldn’t get clarity on dosing instructions from the telemedicine provider who prescribed the compounded semaglutide, leading the patient to search online for medical advice. This resulted in the patient taking five times the intended dose.
In another example, one clinician prescribed 20 units instead of two units, affecting three patients who, after receiving 10 times the intended dose, experienced nausea and vomiting.
Another clinician, who also takes semaglutide himself, tried to recalculate his own dose in units and ended up self-administering a dose 10 times higher than intended.
The FDA previously warned about potential risks from the use of compounded drugs during a shortage as is the case with semaglutide. While compounded drugs can “sometimes” be helpful, according to the agency, “compounded drugs pose a higher risk to patients than FDA-approved drugs because compounded drugs do not undergo FDA premarket review for safety, effectiveness, or quality.”