PATIENT INFORMATION
Diabetes medicines
Diabetes medicines need a specific perioperative plan because fasting changes your risk of low blood sugar, while surgery and illness can raise blood sugar. The plan depends on whether you use tablets, insulin, an insulin pump, an SGLT2 inhibitor, a GLP-1 medicine or a combination.
Medicines that commonly need adjustment
- SGLT2 inhibitors (for example dapagliflozin, empagliflozin, canagliflozin) are a particularly important group to identify early because they are usually stopped several days before scheduled surgery to reduce the risk of perioperative ketoacidosis. They are also used for heart failure and kidney disease, so check even if you do not have diabetes.
- Insulin usually needs adjustment rather than simply being stopped, especially in type 1 diabetes.
- Sulfonylureas (for example gliclazide, glimepiride) can cause low blood sugar while fasting and often need an adjusted plan.
- Metformin is sometimes continued and sometimes withheld, depending on kidney function, the procedure and local protocol.
- GLP-1 medicines have their own considerations. See the GLP-1 page.
Before the day of surgery
- Ask for a written plan, especially if you have type 1 diabetes or use insulin.
- Ask whether your operation can be scheduled early in the day.
- If you use an insulin pump or continuous glucose monitor, tell the team early and bring your supplies.
- Ask what to do if your blood glucose is low while you are fasting.
On the day
- Check your blood glucose as advised and bring your meter or monitor.
- Tell the team if you had a low blood sugar, or treated one, while fasting.
- Tell the team about symptoms such as nausea, vomiting, abdominal pain or unusual drowsiness.
Agree your diabetes treatment plan with the team in advance; do not independently stop all treatment because you are fasting.