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Generic Name: acarbose (ah KAR bose)
Brand Name: Precose

What is Precose?

Precose slows the digestion of carbohydrates in the body, which helps control blood sugar levels.

Precose is used together with diet and exercise to treat type 2 diabetes. This medicine is sometimes used in combination with insulin or other diabetes medications you take by mouth.

Precose may also be used for purposes not listed in this medication guide.

Important Information

You should not use Precose if you have inflammatory bowel disease, an ulcer or blockage in your intestines, or cirrhosis of the liver. Do not use this medicine if you are in a state of diabetic ketoacidosis (call your doctor for treatment with insulin).

Before taking this medicine

You should not use Precose if you are allergic to it, or if you have:

  • inflammatory bowel disease;

  • a blockage in your intestines;

  • a digestive disorder affecting your intestines;

  • intestinal ulcer (of your colon);

  • cirrhosis of the liver; or

  • diabetic ketoacidosis (call your doctor for treatment with insulin).

To make sure Precose is safe for you, tell your doctor if you have:

  • liver disease;

  • kidney disease;

  • a bowel or intestinal disorder; or

  • a stomach disorder.

This medicine is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether Precose passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using this medicine.

Precose is not approved for use by anyone younger than 18 years old.

How should I take Precose?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take Precose with the first bite of a main meal, unless your doctor tells you otherwise.

Your blood sugar will need to be checked often, and you may need other blood tests at your doctor's office.

If you take Precose with insulin or other diabetes medications, your blood sugar could get too low.

Low blood sugar (hypoglycemia) can happen to everyone who has diabetes. Symptoms include headache, hunger, sweating, confusion, irritability, dizziness, or feeling shaky. Always keep a source of dextrose (D-glucose) with you in case you have low blood sugar. When taking Precose, dextrose will work better than cane sugar or table sugar in treating hypoglycemia. Sources of dextrose include honey, dates, raisins, plums, dried prunes, grapes, or glucose tablets. Be sure your family and close friends know how to help you in an emergency.

If you have severe hypoglycemia and cannot eat or drink, use a glucagon injection. Your doctor can prescribe a glucagon emergency injection kit and tell you how to use it.

Also watch for signs of high blood sugar (hyperglycemia) such as increased thirst, increased urination, hunger, dry mouth, fruity breath odor, drowsiness, dry skin, blurred vision, and weight loss.

Check your blood sugar carefully during times of stress, travel, illness, surgery or medical emergency, vigorous exercise, or if you drink alcohol or skip meals. These things can affect your glucose levels and your dose needs may also change. Do not change your medication dose or schedule without your doctor's advice.

Precose is only part of a complete treatment program that may also include diet, exercise, weight control, regular blood sugar testing, and special medical care. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the missed dose as soon as you remember (be sure to take it with a meal). If it has been longer than 15 minutes since you started your meal, you may still take Precose but it may be less effective than taking it with the first bite of the meal. Do not take this medicine between meals, and do not take extra medicine to make up a missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

In case of overdose, do not eat or drink anything containing carbohydrates for the next 4 to 6 hours.

What should I avoid while taking Precose?

Avoid drinking alcohol. It can lower your blood sugar.

Avoid taking a digestive enzyme such as pancreatin, amylase, or lipase at the same time you take Precose. These enzymes can make it harder for your body to absorb this medicine. Products that contain digestive enzymes include Arco-Lase, Cotazym, Donnazyme, Pancrease, Creon, and Ku-Zyme.

Precose side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • severe constipation;

  • severe stomach pain, diarrhea that is watery or bloody;

  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin; or

  • liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Precose?

You may be more likely to have hyperglycemia (high blood sugar) if you take Precose with other drugs that can raise blood sugar, such as:

This list is not complete. Other drugs may interact with acarbose, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your pharmacist can provide more information about Precose.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 9.01.

Date modified: March 06, 2018
Last reviewed: September 10, 2015