How does this medication work? What will it do for me?

Acarbose is an antidiabetic medication known as an α-glucosidase inhibitor. Acarbose is used to control blood glucose for people with type 2 diabetes when diet, exercise, and weight reduction have not controlled it well enough on their own.

This medication is often added to other diabetes medications when additional blood glucose control is needed. Acarbose works by preventing the breakdown of starch into sugar (by blocking the α-glucosidase enzyme) and helps to lower blood sugar levels after meals.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

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What form(s) does this medication come in?

50 mg
Each round, off-white, scored tablet, marked with "G50" on one side and the Bayer cross on the other, contains acarbose 50 mg. Nonmedicinal ingredients: cornstarch, magnesium stearate, microcrystalline cellulose, and silicon dioxide. Preservative- and dye-free.

100 mg
Each round, off-white, scored tablet, marked with "G100" on one side and the Bayer cross on the other, contains acarbose 100 mg. Nonmedicinal ingredients: cornstarch, magnesium stearate, microcrystalline cellulose, and silicon dioxide. Preservative- and dye-free.

How should I use this medication?

The recommended adult dose of acarbose varies. The starting dose is 50 mg once daily, with a gradual increase in dose as needed to control blood glucose. The maximum daily dose is 100 mg three times daily, taken with the first bite of a meal.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Take this medication regularly in order to keep blood glucose under control. If you forget a dose, start your regular dosing schedule again with your next meal. Do not take a double dose to make up for a missed one. Do not stop taking this medication without first consulting your doctor.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

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Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to acarbose or any ingredients of the medication
  • have a condition that may worsen as a result of increased gas formation in the intestine (e.g., larger hernias)
  • have a predisposition to intestinal blockage
  • have chronic intestinal conditions associated with severe problems with digestion or absorption
  • have colonic ulceration
  • have diabetic ketoacidosis
  • have inflammatory bowel disease
  • have partial intestinal blockage
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What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal or stomach pain
  • bloating or gas
  • diarrhea

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • yellow eyes or skin

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

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Are there any other precautions or warnings for this medication?

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Decreased response: Over a period of time, blood glucose may be less easily controlled with acarbose or other diabetes medications because of worsening of diabetes. If acarbose fails to lower your blood glucose to target levels, talk to your doctor. Your doctor may stop and replace acarbose or have another blood glucose-lowering medication added to it.

Diabetes complications: Acarbose (or any other antidiabetic agent) has not been shown to prevent the development of complications peculiar to diabetes, although the onset of such complications is delayed by good blood glucose control.

Diet: Acarbose must be taken along with a proper dietary regimen and not seen as a substitute for diet.

Illness or stress: It is possible to lose control of blood sugar during illness or stressful situations such as infection, trauma, or surgery. Under these conditions, your doctor may consider stopping the medication and prescribe insulin until the situation improves.

Liver or kidney disease: If you have kidney or liver disease you should use caution while taking acarbose and should be closely monitored by your doctor.

Low blood sugar: Because of the way it works, acarbose will not cause low blood sugar when taken on its own. However, acarbose may increase the risk of low blood sugar caused by sulfonylurea medications such as glyburide if taken at the same time. See information on glyburide for further details about signs and management of low blood sugar.

Sucrose usage: Increased use of sucrose (cane sugar) and foods that contain sugar or starch can lead to stomach problems (e.g., flatulence and bloating) as well as loose stools and, occasionally, diarrhea.

Pregnancy: There are no adequate and well-controlled studies on the use acarbose by pregnant women. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if acarbose passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of acarbose for children and adolescents less than 18 years old have not been established.

What other drugs could interact with this medication?

There may be an interaction between acarbose and any of the following:

  • cholestyramine
  • corticosteroids (e.g., prednisone)
  • digestive enzyme preparations (e.g., amylase, pancreatin)
  • digoxin
  • diuretics (e.g., hydrochlorothiazide, furosemide)
  • estrogens (e.g., oral contraceptives, hormone replacement therapy)
  • intestinal absorbents (e.g., charcoal)
  • isoniazid
  • nicotinic acid
  • phenothiazines (e.g., promethazine)
  • phenytoin
  • sympathomimetic medications (e.g., epinephrine, pseudoephedrine)
  • thyroid products (e.g., levothyroxine)
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.