Sounds like 'ah-KAR-bose'

Acarbose is used to treat type 2 diabetes. Find out how to take it safely and possible side effects. Acarbose is also called Accarb.

Type of medicine Also called
  • Medication for type 2 diabetes
  • Glucobay®
  • Accarb®

What is acarbose?

Acarbose is used to treat type 2 diabetes, together with exercise, good nutrition, weight loss and other lifestyle measures. It may be used alone or with other medicines for diabetes. Acarbose works by slowing the digestion and absorption of carbohydrates (sugars) and in this way lowers high blood glucose after each meal. To work properly acarbose must be taken at the start of a meal (with the first bites). 
Read more about type 2 diabetes and medicines for type 2 diabetes.  


In Aotearoa New Zealand acarbose is available as tablets (50 mg and 100 mg).

  • The starting dose of acarbose is 50 milligrams 3 times a day.
  • Depending on your blood glucose level, your doctor may increase your dose to 100 milligrams 3 times a day. Some people may need a higher dose.    
  • Always take your acarbose exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much acarbose to take, how often to take it and any special instructions.

How to take acarbose

  • Timing of your doses: Swallow your tablet with a drink of water at the beginning of a meal, or if you prefer, you can chew the tablet with your first mouthful of food. Acarbose should be taken 3 times a day, with breakfast, lunch and dinner. Do not take it between meals or with small snacks. 
  • Missed dose: If you forget your dose with your meal, wait to take the next dose with your next meal. Do not take double the dose and do not take the tablets between meals. 
  • Keep taking acarbose regularly. To control your diabetes, you must keep taking acarbose every day. 

Things to consider while you are taking acarbose

  • Avoid eating sucrose-containing products such as sugar, soft drinks or lollies. They may cause stomach pain or even runny poo (diarrhoea) if taken while you are on acarbose tablets.
  • Limit alcohol while you are taking acarbose. Having the occasional drink while you are taking acarbose is safe. However, regularly drinking excessive amounts increase your chance of side effects and reduce the effects of acarbose. Read more about diabetes and alcohol
  • If you are sick and not eating, ask your healthcare provider for advice. They may recommend that you stop taking acarbose until you are better. Read more about diabetes sick day plan

Possible side effects 

Like all medicines, acarbose can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Bloating or gas in the tummy
  • Diarrhoea (loose, watery stools)
  • These are very common when you first start taking acarbose (they affect more than 1 in 10 people).   
  • Eating foods containing sucrose (sugar) with acarbose is likely to make these symptoms worse.
  • These effects usually go away with time. Tell your doctor if troublesome.
  • Nausea (feeling sick)
  • Vomiting (being sick)
  • Indigestion
  • Loss of appetite 
  • These are less common side effects (they affect fewer than 1 in 10 people).   
  • Tell your doctor if troublesome.
  • Signs of low blood glucose (hypoglycaemia) such as feeling weak, faint, dizzy or irritable. You may get a headache, tremor (shakes) or blurred vision.
  • Very rarely acarbose may lower your blood glucose too much. This is most likely to occur if you are taking acarbose with other diabetes medicines. 
  • If this happens, do not treat a
    "hypo" with cane sugar (sucrose). It
    will not work fast enough. Instead,
    you should take glucose, 
    honey (10 mL) or 1 cup (240 mL) of milk.
    Glucose is available in tablets,
    syrup or sweets, which you can buy from your pharmacy.
  • Tell your doctor or nurse if this happens.
  • Signs of an allergic reaction such as skin rash, itching, swelling of your lips, face and mouth, or difficulty breathing. 
  • Allergy to acarbose is very rare.
  • Tell your doctor immediately or phone Healthline free on 0800 611 116.
  • Signs of problems with your liver such as yellowing of your skin or eyes, dark urine or pain in your abdomen. 
  • Liver problems are very rare.
  • Tell your doctor immediately or phone Healthline free on 0800 611 116. 
For more information on side effects, see the Medsafe consumer information leaflets Glucobay and Accarb.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


Acarbose may interact with a few medications and herbal supplements, so check with your doctor or pharmacist before starting acarbose or before starting any new medicines.

Learn more

The following links have more information on acarbose.

Acarbose (Māori) NZ Formulary Patient Information
Glucobay Medsafe Consumer Information Sheet


  1. Acarbose New Zealand Formulary
  2. Managing patients with type 2 diabetes: from lifestyle to insulin BPAC, NZ, 2015
  3. Glucobay Medsafe Datasheet

Additional resources for healthcare professionals

Antidiabetic drugs NZ Formulary
Interactions checker NZ Formulary
Type 2 diabetes management guidance NZ Society for the Study of Diabetes (NZSSD)

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 05 May 2019