Can I take dapagliflozin with metformin and insulin glargine? What are the ketoacidosis sick-day rules?
Public question: "My doctor added dapagliflozin 10 mg to metformin 1000 mg twice daily and insulin glargine 24 units. What should I watch for?" Evidence Desk answer: Dapagliflozin alone rarely causes low blood sugar, but adding it to insulin can, so prescribers often reduce basal insulin by about 10-20% if A1c is near goal or glucose runs low. The bigger safety issue is euglycemic ketoacidosis. Blood glucose may read only 150-250 mg/dL while ketones are high. Warning signs are nausea, vomiting, abdominal pain, fast breathing, and unusual fatigue. Sick-day rule: during vomiting, diarrhea, fasting, or heavy alcohol use, hold the SGLT2 inhibitor and call your clinician. Stop it at least 3 days before scheduled surgery. Never stop basal insulin without instructions. Also keep the genital area clean and dry, since yeast infections occur in roughly 5-10% of users.
The Farxiga label warns of ketoacidosis, including euglycemic cases, and advises stopping dapagliflozin at least 3 days before scheduled surgery. It also notes a risk of hypoglycemia when combined with insulin or insulin secretagogues, and that a lower insulin dose may be needed.