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 (NBM) period / during liver reduction (LRD) diet.
Advice in the perioperative period
Elective surgery
Gliclazide should be taken as normal the day prior to surgery
EXCEPT:
- patients undertaking a liver reduction diet pre-operatively – see Patients undergoing surgery that requires liver reduction diet (LRD)
Morning and afternoon surgery
Omit all doses due on day of surgery.
EXCEPT:
- as indicated above (also see below)
Patients undergoing surgery that requires liver reduction diet (LRD) (e.g. bariatric surgery, gallbladder surgery)
For patients with type 2 diabetes mellitus commencing liver reduction diet (LRD), patients taking gliclazide are at increased risk of hypoglycaemia during the LRD and it should be discontinued when the LRD commences (see Further information).
For patients with type 2 diabetes mellitus not following a LRD, follow the advice above for elective surgery.
Emergency surgery
In the event of emergency surgery and the patient has already taken their gliclazide dose(s) monitor blood glucose levels closely and treat any hypoglycaemia accordingly.
Perioperativeconsiderations
Commence variable rate intravenous insulin infusion (VRIII) perioperatively where indicated (see Further information) and omit sulfonylurea during VRIII treatment.
Ensure emergency treatment of hypoglycaemia is prescribed, i.e. Glucogel® and 20% dextrose. Rapid acting insulin should also be prescribed.
Post-operative advice
Restart once eating and drinking normally and VRIII (where applicable) has been stopped. Due to the risk of hypoglycaemia with gliclazide, 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 gliclazide will restart their medication the day after surgery, once they are eating and drinking normally and VRIII (where applicable) has been stopped.
Patients undergoing bariatric surgery
Improved glycaemic control is expected because of reduced calorie intake, early satiety and weight loss following bariatric surgery, therefore gliclazide should be discontinued post-operatively. Blood glucose should be monitored until eating habits and food intake stabilises. Patients should have their need for ongoing pharmacological management of their diabetes reviewed by their GP and / or bariatric surgical team.
Interactions with common anaesthetic agents
None.
Interactions 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 hypoglycaemia.
Antimicrobials
Clarithromycin slightly increases, and sulfamethoxazole (found in co-trimoxazole) increases, gliclazide exposure which may cause hypoglycaemia. Increase CBG monitoring with concomitant use and adjust dose of gliclazide if necessary.
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)). Patients expected to miss more than one meal should have VRIII if they develop hyperglycaemia (CBG >12mmol/L).
Liver reduction diet (LRD)
Patients with a high BMI often have a large, fatty liver which can cause difficulty for laparoscopic surgery, as the stomach cannot be easily accessed. The LRD typically starts 10 – 15 days prior to bariatric surgery and is based on low calories, in particular low carbohydrate and fat. This forces stored glycogen to be released from the liver (plus some water), making it softer, more flexible and easier to move. Due to the reduced calorie and carbohydrate intake, CBG levels will most likely be reduced. Since gliclazide cause hypoglycaemia, the risk is increased due to the reduction in dietary intake and it should be stopped at the start of the LRD.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 27th February 2021]
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]
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 27th February 2021]
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]
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]