Sulfonylureas


 

Glibenclamide, Gliclazide, Glimepiride, Glipizide, Tolbutamide

[Wockhardt, the only UK manufacturer of glibenclamide, have discontinued production.  At the current time, this preparation remains in the British National Formulary and has been included in this monograph as unlicensed imports are available for patients in whom a switch to an alternative is inappropriate] 

  Issues for Surgery


Increased risk of post-operative infection and delayed wound healing due to poor glycaemic control if omitted.

Hypoglycaemia if continued during nil by mouth period.


  Advice in the Perioperative period


Elective Surgery

Sulfonylureas should be taken as normal the day prior to surgery1.

Morning Surgery
Once daily dosing (in the morning) – omit the dose on day of surgery1

Twice daily dosing – omit the morning dose on day of surgery1

Afternoon Surgery
Once daily dosing (in the morning) – omit the dose of day of surgery1

Twice daily dosing – omit both doses on day of surgery1

Emergency Surgery

In the event of emergency surgery and the patient has already taken their sulfonylurea dose(s) monitor blood glucose levels closely and treat any hypoglycaemia accordingly.

Perioperative Considerations

Commence variable rate intravenous insulin infusion (VRIII) perioperatively where indicated (see Further Information) and omit sulfonylurea during VRIII treatment1..

Ensure emergency treatment of hypoglycaemia is prescribed i.e. Glucogel® and 20% dextrose. Rapid acting insulin should also be prescribed1, 2.

Post-operative Advice

Restart once eating and drinking normally and VRIII (where applicable) has been stopped1, 2. Due to the risk of hypoglycaemia with sulfonylureas, capillary blood glucose (CBG) should be monitored post-operatively and consideration should be given to omitting or reducing the dose if reduced food intake. Monitor renal function – dose reduction may be necessary if decline in renal function post-operatively.

NB: Patients undergoing afternoon surgery and taking twice daily sulfonylurea will restart their medication the day after surgery, once they are eating and drinking normally and VRIII (where applicable) has been stopped.


  Interaction(s) with Common Anaesthetic Agents


None2, 3, 4, 5, 6, 7.


  Interaction(s) with other Common Medicines used in the Perioperative Period


Non-Steroidal Anti-inflammatory Drugs (NSAIDs)

Caution with concomitant use of NSAIDs as they may cause hypoglycaemia3, 4, 5, 6, 7.

Antibiotics

Clarithromycin slightly increases, and sulfamethoxazole (found in co-trimoxazole) increases, sulfonylurea exposure which may cause hypoglycaemia2, 3, 4, 5, 6, 7. Case reports of hypoglycaemia have been noted with concomitant use of glibenclamide and ciprofloxacin7. Increase CBG monitoring with concomitant use and adjust dose of sulfonylurea if necessary7.


  Further Information

 

VRIII

Patients with a planned short starvation period (no more than one missed meal in total) should be managed by modification of their usual diabetes medication, avoiding VRIII wherever possible (although VRIII may be necessary if emergency surgery or in people with poorly controlled diabetes (HbA1c >69mmol/mol))1. Patients expected to miss more than one meal should have VRIII if they develop hyperglycaemia (CBG >12mmol/L)1.


  References


  1. Centre for Perioperative Care. Guideline for Perioperative Care for People with Diabetes Mellitus Undergoing Elective and Emergency Surgery (March 2021). Available at: https://cpoc.org.uk/guidelines-resources/guidelines [Accessed on 8th March 2021]
  2. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 27th February 2021]
  3. Summary of Product Characteristics – Diamicron® (gliclazide) 80mg Tablets. Servier Laboratories Limited. Accessed via www.medicines.org.uk 27/02/2021 [date of revision of the text February 2020]
  4. Summary of Product Characteristics – Gliclazide Accord-UK 30mg Prolonged-release Tablets. Accord-UK Ltd. Accessed via www.medicines.org.uk 27/02/2021 [date of revision of the text February 2021]
  5. Summary of Product Characteristics – Glimepiride 1mg Tablets. Accord Healthcare Ltd. Accessed via www.medicines.org.uk 27/02/2021 [date of revision of the text December 2020]
  6. Summary of Product Characteristics – Glipizide 5mg Tablets. Mylan. Accessed via www.medicines.org.uk 27/02/2021 [date of revision of the text May 2017]
  7. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 27th February 2021]