Euglycemic ketoacidosis with SGLT2 inhibitors
Sodium-glucose cotransporter 2 (SGLT2) inhibitors such as empagliflozin lower glucose by making the kidneys excrete glucose in the urine. Because glucose is lost in the urine, insulin levels fall and the body shifts toward fat breakdown and ketone production. During illness with vomiting, poor intake, and dehydration, this can progress to euglycemic diabetic ketoacidosis, in which ketones and acidosis rise while glucose stays near normal or only mildly raised. A glucose of 148 mg/dL does not rule out ketoacidosis in a client taking an SGLT2 inhibitor.
The correct sick-day instruction
The nurse tells her to hold empagliflozin and to check her ketones right away, even though her glucose is in range. Because she cannot keep fluids down, she also needs prompt medical review: persistent vomiting risks dehydration, kidney injury, and ketoacidosis. Metformin is usually held during vomiting or dehydration as well, because dehydration reduces kidney clearance and raises the risk of lactic acidosis. Both drugs are restarted when she is eating and drinking normally, as directed.
| Instruction | Problem or benefit |
|---|
| Continue both drugs | Ignores ketoacidosis and dehydration risk |
| Extra metformin dose | Raises lactic acidosis risk; no effect on ketosis |
| Hold empagliflozin, test ketones now | Correct sick-day action for SGLT2 inhibitors |
| Test ketones only if glucose above 240 mg/dL | General rule; misses euglycemic ketoacidosis |
Why the 240 mg/dL rule does not apply
Many sick-day plans advise checking ketones when glucose exceeds 240 mg/dL (13.3 mmol/L). That threshold works for most clients because diabetic ketoacidosis usually comes with marked hyperglycemia. With SGLT2 inhibitors, glucose may stay low enough that the threshold is never reached, so ketones are checked during illness regardless of the glucose level. Watch out! The option with a specific number looks precise, but it applies a general rule that misses the SGLT2-specific risk.
Exam takeaway
Signs of ketoacidosis include nausea, vomiting, abdominal pain, unusual tiredness, and rapid, deep breathing; she currently has no difficulty breathing, but her vomiting alone is enough reason to check ketones and seek review. Key point! On an SGLT2 inhibitor, illness with vomiting or dehydration means: hold the drug, check ketones even with normal glucose, and seek prompt medical review.