UK Clinical Pharmacy Association


Issues for surgery

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

Hypoglycaemia if continued during nil by mouth (NBM) period.

Advice in the perioperative period

Elective surgery 

Acarbose should be taken as normal the day prior to surgery.

Morning surgery: Omit morning dose if nil by mouth.

Afternoon surgery: Take morning dose if eating.

Patients undergoing bariatric surgery

For patients with type 2 diabetes mellitus commencing liver reduction diet (LRD), although acarbose itself does not induce hypoglycaemia, consideration should be given to stopping it 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 acarbose dose(s), monitor capillary blood glucose (CBG) levels closely and treat any hypoglycaemia accordingly.

Perioperative considerations

Commence variable rate intravenous insulin infusion (VRIII) perioperatively where indicated (see Further information) and omit acarbose 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.

Patients undergoing bariatric surgery

Improved glycaemic control is expected because of reduced calorie intake, early satiety and weight loss following bariatric surgery, therefore discontinuation of acarbose should be considered 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


Interactions with other common medicines used in the perioperative period


Further information


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 with type 2 diabetes who are expected to miss more than one meal should have VRIII if they develop hyperglycaemia (CBG >12mmol/L).

Liver reduction diet (LRD)

Most people needing bariatric surgery 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. Whilst acarbose does not cause hypoglycaemia, the reduction in dietary intake means it is unlikely to have any benefit during the LRD.


Centre for Perioperative Care. Guideline for Perioperative Care for People with Diabetes Mellitus Undergoing Elective and Emergency Surgery (March 2021). Available at: [Accessed on 8th March 2021]

Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. [Accessed on 27th February 2021]

Busetto L, Dicker D, Aznar C et al. Practical Recommendations of the Obesity Management Task Force of the European Association for the Study of Obesity for the Post-Bariatric Surgery Medical Management. Obesity Facts 2017;10:597 – 632. DOI: 10.1159/000481825

Summary of Product Characteristics – Acarbose 100mg Tablets. Glenmark Pharmaceuticals Europe Ltd. Accessed via 27/02/2021 [date of revision of the text December 2018]