Diabetes · For patients and their doctors

Diabetes medicines before surgery

Some diabetes medicines must be stopped days before an operation, some need a smaller dose, and some should never be stopped. Enter your procedure and your medicines to get a dated plan: what to take the day before, on the day, and when to restart.

Built by Dr. Khizer Hussain Junaidy · Diabetologist & Bariatric Physician · Telangana State Medical Council 04937 · Reviewed September 2026

A guide to discuss with your surgeon, anaesthetist and diabetes doctor, not a prescription. For adults having a planned procedure. If your hospital gives you different instructions, follow the hospital. Nothing you enter leaves this device.

1. Your procedure

Type of procedure

Minor procedure under local anaesthetic, and you can eat normally (for example cataract, dental or skin procedures) Day-case procedure with sedation or anaesthesia, missing no more than one meal (for example endoscopy, hernia, small operations) Major operation with a hospital stay, or likely to miss more than one meal Colonoscopy or another procedure with bowel preparation (clear fluids the day before) Bariatric (weight-loss) surgery with a low-calorie or liquid diet before it

Time of the procedure

Morning Afternoon

Date of the procedure optional

Contrast dye (an injection for X-ray or CT pictures) is planned This is an emergency operation

2. Your diabetes

Type of diabetes

Type 2 Type 1 Other

Latest HbA1c %

Kidney function, eGFR optional

4. Insulin

How you take insulin

Doses are optional. Enter them to see the exact number of units; leave them blank to see percentages.

5. Your plan

Book a review

Caspian Healthcare reception: 89193 41154.

Rules used (CPOC 2023 unless marked)

Medicine	Day before	Day of surgery
Metformin	As normal	Once or twice daily: as normal; three times daily: omit lunchtime. Major surgery: hold (ADA). Contrast with eGFR below 60: omit and for 48 h
Sulfonylurea	As normal	Morning list: omit morning dose, evening dose if eating. Afternoon list: omit
Acarbose, meglitinide	As normal	Omit if not eating; afternoon list: morning dose with breakfast
Pioglitazone, DPP-4 inhibitor, GLP-1 RA	As normal	As normal (GLP-1: 24 h clear liquids if higher aspiration risk)
SGLT2 inhibitor	Omit	Omit. Major surgery, bowel preparation, bariatric: stop at least 3 days before, ertugliflozin 4 (US labels, ADA)
Once-daily basal	Evening dose: 80%	Morning dose: 80% (NPH 50%, ADA)
Twice-daily premixed	As normal	Half the morning dose; evening dose if eating
Basal-bolus	Basal as above	Omit mealtime doses for missed meals
Bowel preparation day (Chirila 2023)	Basal 50% (type 1: 80%); NPH 80%; mealtime and premix 50%; sulfonylurea and metformin omitted	NPH 50%; DPP-4 inhibitor held until after
Bariatric diet (JBDS-IP 21)	From diet start: insulin halved; sulfonylurea, meglitinide, SGLT2 inhibitor stopped	Do not omit basal insulin; VRIII

Choices without published guidance: imeglimin, saroglitazar and quick-release bromocriptine are omitted on the day and restarted with eating; remogliflozin follows the SGLT2 rule; premixed insulin on the bowel preparation day is halved, in line with the mealtime insulin rule.

Call the hospital or go to an emergency department now if

You are vomiting, have tummy pain, fast breathing or feel drowsy, especially if you take an SGLT2 medicine or have type 1 diabetes. This can be ketoacidosis, even with normal glucose.
Your glucose stays below 70 mg/dL after treatment, or you are too drowsy to eat or drink.
Your glucose stays above 300 mg/dL, or blood ketones are 1.5 mmol/L or more.
After the operation: fever, a red or leaking wound, or you cannot keep fluids down.

Sources

Centre for Perioperative Care. Guideline for perioperative care for people with diabetes mellitus undergoing elective and emergency surgery, version 3.0, 2023. CPOC
Levy NA, et al. Association of Anaesthetists and JBDS-IP guidance on peri-operative care of people with diabetes. Anaesthesia 2026. doi:10.1111/anae.70181
American Diabetes Association. Standards of Care in Diabetes, section 16, Diabetes care in the hospital. Diabetes Care 2025 and 2026 supplements. Diabetes Care
US prescribing information for dapagliflozin, empagliflozin, canagliflozin and ertugliflozin (withhold before surgery). DailyMed
ASA, AGA, ASMBS, ISPCOP and SAGES. Multi-society clinical guidance on GLP-1 receptor agonists before procedures, October 2024. ASA
El-Boghdadly K, et al. UK multidisciplinary consensus on GLP-1 and GIP/GLP-1 receptor agonists around surgery. Anaesthesia 2025. doi:10.1111/anae.16541
Australian Diabetes Society, ANZCA, GESA and NACOS. Clinical practice recommendations on GLP-1 receptor agonists before procedures, 2025. doi:10.1177/0310057X251355288
Houlden RL, et al. Practical guidance on once-weekly basal insulin. Endocrine Practice 2025.
Chirila A, et al. Diabetes medicine adjustment for colonoscopy bowel preparation. J Can Assoc Gastroenterol 2023;6:26. JCAG
Joint British Diabetes Societies for Inpatient Care. Guideline 21, metabolic and bariatric surgery, version 1.0, March 2026. ABCD
GIRFT cataract guide 4: perioperative management of patients with medical comorbidities, October 2022. GIRFT
European Society of Urogenital Radiology. Contrast media safety guidelines: metformin. ESUR

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