A 60-year-old woman with type 2 diabetes undergoing abdominal surgery is nil by mouth post-operatively. Her last HbA1c was 85 mmol/mol and inpatient glucose readings are elevated. She reports fatigue, thirst, and polyuria. Select the most appropriate antidiabetic medication.

• A. Metformin
• B. Gliclazide
• C. Pioglitazone
• D. Actrapid (soluble insulin)

Answer: (D)

Hyperglycemia in the immediate postoperative period, especially when the patient is nil by mouth, is best managed with injectable insulin because oral agents cannot be reliably given and their potential risks are heightened during fasting and surgical stress. Metformin is withheld around surgery due to risks of lactic acidosis in unstable states and reduced perfusion, and it cannot be given by mouth in this scenario. Gliclazide and pioglitazone are oral agents with slower onset (and higher risk of hypoglycemia during fasting for gliclazide) that don’t allow rapid, flexible titration in the acute hospital setting.

Insulin, specifically a short-acting soluble insulin like Actrapid, can be given parenterally and adjusted quickly to correct hyperglycemia in a fasting patient. It provides rapid onset and allows tight, controllable management of glucose levels during the perioperative period. The elevated HbA1c shows chronic poor control, but the immediate need is to manage high glucose safely now, which insulin achieves most effectively.