Management of Metformin and Gliclazide Prior to Colonoscopy

Metformin Management

The American Society of Anesthesiologists recommends stopping metformin the night before colonoscopy to reduce the risk of lactic acidosis in patients with normal renal function 1, 4, 5
Patients with renal impairment (creatinine clearance <60 mL/min) are at higher risk of lactic acidosis and should be assessed before the procedure 4, 6
The European Society of Anesthesiology suggests that metformin should not be restarted until 48 hours after the procedure and after confirming adequate renal function 1

The American Diabetes Association recommends withholding gliclazide on the morning of the colonoscopy and considering glucose infusion to prevent hypoglycemia in patients remaining NPO 2, 3
Sulfonylureas like gliclazide can cause hypoglycemia during fasting periods, and blood glucose levels should be monitored before and during the procedure 2, 3

The American College of Gastroenterology suggests confirming normal renal function before restarting metformin (48 hours post-procedure) and monitoring for symptoms of lactic acidosis 1, 6
Gliclazide should be resumed with the first meal after the procedure, and blood glucose levels should be monitored after restarting medication 3