Which oral hypoglycemic drug is associated with a risk of intraoperative lactic acidosis if not discontinued at least 24 hours before surgery?

Which oral hypoglycemic drug is associated with a risk of intraoperative lactic acidosis if not discontinued at least 24 hours before surgery?

• A. Metformin (Glucophage)
• B. Glyburide (DiaBeta, Micronase)
• C. Glipizide (Glucotrol)
• D. Tolbutamide (Orinase)

Answer: (A)

Metformin is the oral hypoglycemic most associated with lactic acidosis in the perioperative period. It can impair mitochondrial respiration and hepatic lactate clearance, so when tissue perfusion is blunted during surgery or renal function is reduced, lactate can accumulate and lead to lactic acidosis. Because metformin is renally cleared, withholding it at least 24 hours before surgery helps prevent this accumulation and the risk of intraoperative lactic acidosis. The other agents listed (sulfonylureas) mainly pose a risk of hypoglycemia and do not carry a significant lactic acidosis risk in this setting, so they don’t carry the same perioperative warning.

Metformin is the oral hypoglycemic most associated with lactic acidosis in the perioperative period. It can impair mitochondrial respiration and hepatic lactate clearance, so when tissue perfusion is blunted during surgery or renal function is reduced, lactate can accumulate and lead to lactic acidosis. Because metformin is renally cleared, withholding it at least 24 hours before surgery helps prevent this accumulation and the risk of intraoperative lactic acidosis. The other agents listed (sulfonylureas) mainly pose a risk of hypoglycemia and do not carry a significant lactic acidosis risk in this setting, so they don’t carry the same perioperative warning.