Precose Diabetes Type 2 Treatment - Precose Patient Information

Brand names: Precose
Generic name: Acarbose

Precose, acarbose, full prescribing information

What is Precose and why is Precose prescribed?

Precose is an oral medication used to treat type 2 (noninsulin-dependent) diabetes when high blood sugar levels cannot be controlled by diet alone. Precose works by slowing the body's digestion of carbohydrates so that blood sugar levels won't surge upward after a meal. Precose may be taken alone or in combination with certain other diabetes medications.

Most important fact about Precose

Always remember that Precose is an aid to, not a substitute for, good diet and exercise. Failure to follow the diet and exercise plan recommended by your doctor can lead to serious complications such as dangerously high or low blood sugar levels. If you are overweight, losing pounds and exercising are critically important in controlling your diabetes. Remember, too, that Precose is not an oral form of insulin and cannot be used in place of insulin.

How should you take Precose?

Do not take more or less of Precose than directed by your doctor. Precose is usually taken 3 times a day with the first bite of each main meal.

  • If you miss a dose...
    Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time. Taking Precose with your 3 main meals will help you to remember your medication schedule.
  • Storage instructions...
    Keep the container tightly closed. Protect from temperatures above 77°F. Store away from moisture.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Precose.

If side effects do occur, they usually appear during the first few weeks of therapy and generally become less intense and less frequent over time. They are rarely severe.

    • More common side effects may include:
      Abdominal pain, diarrhea, gas


Why should Precose not be prescribed?

Do not take Precose when suffering diabetic ketoacidosis (a life-threatening medical emergency caused by insufficient insulin and marked by mental confusion, excessive thirst, nausea, vomiting, headache, fatigue, and a sweet fruity smell to the breath).

You should not take Precose if you have cirrhosis (chronic degenerative liver disease). Also avoid Precose therapy if you have inflammatory bowel disease, ulcers in the colon, any intestinal obstruction or chronic intestinal disease associated with digestion, or any condition that could become worse as a result of gas in the intestine.

Special warnings about Precose

Every 3 months during your first year of treatment, your doctor will give you a blood test to check your liver and see how it is reacting to Precose. While you are taking Precose, you should check your blood and urine periodically for the presence of abnormal sugar (glucose) levels.

Even people with well-controlled diabetes may find that stress such as injury, infection, surgery, or fever results in a loss of control over their blood sugar. If this happens to you, your doctor may recommend that Precose be discontinued temporarily and injected insulin used instead.

When taken alone, Precose does not cause hypoglycemia (low blood sugar), but when you take it in combination with other medications such as Diabinese or Glucotrol, or with insulin, your blood sugar may fall too low. If you have any questions about combining Precose with other medications, be sure to discuss them with your doctor.

If you are taking Precose along with other diabetes medications, be sure to have some source of glucose available in case you experience any symptoms of mild or moderate low blood sugar. (Table sugar won't work because Precose inhibits its absorption.)

  • Symptoms of mild hypoglycemia may include:
    Cold sweat, fast heartbeat, fatigue, headache, nausea, and nervousness
  • Symptoms of more severe hypoglycemia may include:
    Coma, pale skin, and shallow breathing

Severe hypoglycemia is an emergency. Contact your doctor immediately if the symptoms occur.

Possible food and drug interactions when taking Precose

When you take Precose with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before taking Precose with the following:

  • Airway-opening drugs
  • Calcium channel blockers (heart and blood pressure medications)
  • Charcoal tablets
  • Digestive enzyme preparations
  • Digoxin
  • Estrogens
  • Isoniazid
  • Major tranquilizers
  • Nicotinic acid
  • Oral contraceptives
  • Phenytoin
  • Steroid medications
  • Thyroid medications
  • Water pills (diuretics)

Special information if you are pregnant or breastfeeding

The effects of Precose during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, tell your doctor immediately. Since studies suggest the importance of maintaining normal blood sugar levels during pregnancy, your doctor may prescribe injected insulin. It is not known whether Precose appears in breast milk. Because many drugs do appear in breast milk, you should not take Precose while breastfeeding.

Recommended dosage for Precose


The recommended starting dose of Precose is 25 milligrams (half of a 50-milligram tablet) 3 times a day, taken with the first bite of each main meal. Some people need to work up to this dose gradually and start with 25 milligrams only once a day. Your doctor will adjust your dosage at 4- to 8-week intervals, based on blood tests and your individual response to Precose. The doctor may increase the medication to 50 milligrams 3 times a day or, if needed, 100 milligrams 3 times a day. You should not take more than this amount. If you weigh less than 132 pounds, the maximum dosage is 50 milligrams 3 times a day.

Precose Tablets

If you are also taking another oral antidiabetic medication or insulin and you show signs of low blood sugar, your doctor will adjust the dosage of both medications.


Safety and effectiveness of Precose in children have not been established.


An overdose of Precose alone will not cause low blood sugar. However, it may cause a temporary increase in gas, diarrhea, and abdominal discomfort. These symptoms usually disappear quickly. However, in the event of an overdose, do not take any carbohydrate drinks or meals until the symptoms have passed.

last updated 01/2008

Precose, acarbose, full prescribing information

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APA Reference
Staff, H. (2008, January 31). Precose Diabetes Type 2 Treatment - Precose Patient Information, HealthyPlace. Retrieved on 2024, June 18 from

Last Updated: March 10, 2016

Medically reviewed by Harry Croft, MD

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