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Updated 2 Feb 2023 | Alpha glucosidase inhibitors


Tablets containing 50mg acarbose
Tablets containing 100mg acarbose

Drugs List

  • acarbose 100mg tablets
  • acarbose 50mg tablets
  • Therapeutic Indications


    Non-insulin dependent diabetes mellitus where patient is inadequately controlled by diet alone or diet and oral hypoglycaemics.


    Acarbose is an inhibitor of intestinal glucosidase and delays the digestion of starch and sucrose to absorbable monosaccharides.

    Large individual variation in glucosidase activity in the intestinal mucosa necessitates a flexible dosage regimen with treatment based on clinical response and tolerance to intestinal side effects.

    Acarbose is intended for continuous long-term treatment.


    Initial dose: 50mg once or twice a day.
    Maintenance dose: 50mg three times a day. After six to eight weeks, this can be increased to 100mg three times a day if necessary.
    Maximum dose: 200mg three times a day.


    Not licensed for use in children under 18 years of age.

    Patients with Renal Impairment

    The manufacturer states that acarbose is contraindicated if creatinine clearance is less than 25ml/min/1.73 square metre.

    The Renal Drug Handbook states that it should be avoided when glomerular filtration rate (GFR) is less than 25ml/min.

    Patients with Hepatic Impairment

    Contraindicated in hepatic impairment.


    For oral administration.

    Tablets should be chewed with the first mouthful of food or swallowed whole with liquid before a meal.


    Inflammatory bowel disease (Ulcerative colitis and Crohn's disease)

    Partial intestinal obstruction

    Predisposition to intestinal obstruction

    Chronic intestinal diseases associated with digestion/absorption disorders

    Conditions which may deteriorate if gas formation in intestine is increased (e.g. hernia)

    Hepatic impairment

    Creatinine clearance of less than 25ml/min/1.73 square metre

    Children under 18 years

    Pregnancy - (see Pregnancy section)

    Breastfeeding - (see Lactation section)

    Precautions and Warnings

    Acarbose does not cause hypoglycaemia but may potentiate other anti-diabetic agents. In individual cases hypoglycaemic shock may occur (i.e. clinical sequelae of glucose levels less than 1mmol/L resulting in altered conscious levels, confusion or convulsions).
    Hypoglycaemic episodes should be treated with glucose, not sucrose as the digestion and absorption of disaccharides will be delayed by acarbose.

    Persistent diarrhoea requires patient monitoring, a dose reduction or possibly withdrawal of therapy.

    Monitor hepatic function during initial 12 months of treatment or if taking high doses and be aware of possible idiosyncratic hepatic dysfunction. If transaminase rises persist withdraw acarbose and monitor hepatic function weekly until it returns to normal.

    Antacid preparations containing magnesium or aluminium salts should not be administered to alleviate acute gastro intestinal symptoms of high dosage acarbose due to lack of efficacy.

    Advise the patient that if the prescribed diabetic diet is not observed the intestinal side effects may be intensified.

    Pregnancy and Lactation


    Contraindicated in all trimesters of pregnancy as the manufacturer states that safety has not been established.
    Animal studies do not indicate direct or indirect harm with regard to reproduction, embryonic or foetal development, course of gestation or peri- and post natal development.

    When dieting alone is not successful, insulin is the treatment of choice for both Type 1 and Type 2 diabetes during pregnancy as it provides better control of maternal blood glucose than oral hypoglycaemics, and does not cross the placenta. Hyperglycaemia in the mother, particularly in the early stages of gestation, is associated with a number of foetal and maternal adverse effects, including foetal structural abnormalities. Carefully prescribed insulin therapy will provide better control of the mother's blood glucose thereby preventing the foetal and neonatal complications that occur with the disease (Briggs, 2011).

    Although acarbose is poorly absorbed (less than 2% of an oral dose), systemic absorption of metabolites is much higher. Limited data on the use of acarbose during pregnancy does not indicate a defined risk, but as acarbose is normally used in combination with other oral hypoglycaemic drugs insulin remains the treatment of choice for diabetes during pregnancy.

    The risk of congenital malformations in infants of women with type 2 diabetes mellitus who had used diet alone, diet and oral hypoglycaemics or diet and insulin during their pregnancy was published in 1995. There were no statistical differences between the groups with regard to major or minor anomalies. The study found the independent association between major anomalies and poor glycaemic control early in pregnancy and also major anomalies and younger age of onset of diabetes.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Manufacturer contraindicates use of acarbose during breastfeeding. At the time of writing, there are no studies describing the use of acarbose during breastfeeding. However, both Briggs (2011) and Hale (2010) suggest that the amount of acarbose available in the mother's circulation for secretion into milk and the amount then absorbed by a nursing infant would not be of clinical significance.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Effects on Ability to Drive and Operate Machinery

    No adverse effects known.


    Patient should be informed of the importance of following dietary advice, taking regular exercise and of regularly monitoring of blood glucose levels.

    Advise patients that the tablets should be chewed with the first mouthful of food, or swallowed with a little liquid immediately before a meal.

    Advise patients taking insulin or oral hypoglycaemics in addition to acarbose that they should carry glucose to counteract possible hypoglycaemia - sucrose is ineffective in the presence of acarbose.

    Advise patients that their ability to drive or operate machinery may be impaired.

    Inform the patient that he/she needs to inform the Driving and Vehicle Licensing Agency (DVLA) about the medication they are receiving. The Drivers Medical Group at the DVLA will be able to advise the patient on the legal issues surrounding the treatment of diabetes mellitus and driving.

    The DVLA can be contacted by post at the following address:

    Drivers Medical Group, DVLA, Swansea, SA99 1TU

    By phone on 0870 600 0301; or by fax on 0845 850 0095

    Detailed guidance on eligibility to drive, and precautions required, is available from the DVLA.

    Further information concerning diabetes and driving may be obtained from the DVLA website at:

    Side Effects

    Abdominal distension
    Abdominal pain
    Increases in serum transaminases (transient)
    Idiosyncratic hepatic dysfunction
    Abnormal liver function tests
    Soft or liquid stools
    Allergic reaction
    Pneumatosis cystoides intestinalis
    Increases in hepatic enzymes
    Gastro-intestinal pain


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Shelf Life and Storage

    Store in original packaging.

    Store in a dry place below 25 degrees C.

    Further Information

    Last Full Review Date: August 2012

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Medications and Mothers' Milk, 14th Edition (2010) Hale,T. Hale Publishing, Amarillo, Texas.

    Summary of Product Characteristics: Glucobay 100. Bayer plc. Revised April 2012.

    Summary of Product Characteristics: Glucobay 50. Bayer plc. Revised April 2012.

    The Renal Drug Handbook. 3rd edition. (2009) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    NICE Evidence Services Available at: Last accessed: 16 August 2017

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