SGLT2 Inhibitors and Ketoacidosis

Why can SGLT2 inhibitors cause ketoacidosis without very high blood sugar?

Sodium-glucose cotransporter-2 inhibitors, including empagliflozin and dapagliflozin, lower blood sugar by reducing glucose reabsorption in the kidneys. When insulin availability becomes insufficient, the body can increase fat breakdown and ketone production while the medicine continues helping glucose leave through urine. The FDA warns that associated ketoacidosis can occur without very high blood sugar, making symptoms important even when glucose readings seem reassuring. [FDA safety communication](https://www.fda.gov/media/94822/download).

This mechanism helps explain the potential relevance of tracking ketones alongside glucose. On August 25, the FDA authorized Abbott's Libre Duo 10 Day system, which measures both substances in fluid beneath the skin. Its authorization creates an additional monitoring option for eligible people with diabetes; it does not establish that continuous monitoring prevents ketoacidosis specifically in SGLT2-treated patients. The FDA announcement describes accuracy and performance evidence, rather than a demonstrated reduction in medication-associated hospitalizations. [FDA authorization announcement](https://www.fda.gov/news-events/press-announcements/fda-authorizes-first-wearable-device-continuously-monitors-both-ketone-levels-and-blood-sugar).

How should patients balance SGLT2 treatment benefits with ketoacidosis precautions?

SGLT2 inhibitors have an established role beyond lowering glucose. American Diabetes Association guidance recommends medicines from this class with demonstrated benefits for appropriate patients with type 2 diabetes and heart failure or chronic kidney disease. Ketoacidosis is uncommon in people with type 2 diabetes taking these medicines, but risk increases with factors such as insulin deficiency, prolonged fasting, dehydration and very low carbohydrate diets. A discussion about these circumstances helps patients understand when their usual medication routine may need adjustment. [ADA pharmacologic treatment guidance](https://doi.org/10.2337/dc25-S009).

Before planned surgery, patients should obtain instructions from their prescribing and surgical teams. U.S. prescribing information specifies withholding empagliflozin for at least three days, if possible, before surgery or procedures involving prolonged fasting; ertugliflozin requires at least four days. Both labels describe restarting once the patient is clinically stable and eating again. These are minimum interruption periods to incorporate into an individualized plan, rather than a guarantee that ketoacidosis cannot occur. [Empagliflozin prescribing information](https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/204629s063lbl.pdf), [ertugliflozin prescribing information](https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/209803s012lbl.pdf).

Can a ketone reading diagnose diabetic ketoacidosis?

Elevated ketones alone do not establish diabetic ketoacidosis. The international consensus report on hyperglycemic emergencies combines evidence of diabetes or elevated glucose with significant ketosis and metabolic acidosis. It recommends direct blood measurement of beta-hydroxybutyrate, the principal ketoacid involved, for diagnosis and monitoring treatment response. Clinicians also assess electrolytes and acid-base status. Treatment generally involves fluids, insulin and electrolyte management, alongside identifying the trigger. A wearable alert cannot replace that evaluation. [International consensus report](https://doi.org/10.2337/dci24-0032).

For someone taking an SGLT2 inhibitor, nausea, vomiting, abdominal pain, unusual tiredness or difficulty breathing can signal ketoacidosis. The FDA advises stopping the SGLT2 inhibitor and seeking immediate medical attention if symptoms suggest this complication. Severe breathing difficulty, confusion or collapse warrants emergency services. Waiting for a high glucose reading or a wearable alarm could delay necessary care. [FDA patient safety advice](https://www.fda.gov/media/94822/download).