Precose Side Effects

Generic name: acarbose

Medically reviewed by Drugs.com. Last updated on Mar 21, 2025.

Note: This document provides detailed information about Precose Side Effects associated with acarbose. Some dosage forms listed on this page may not apply specifically to the brand name Precose.

Applies to acarbose: oral tablet.

Precautions

Your doctor will want to check your progress at regular visits , especially during the first few weeks you take this medicine.

It is very important to follow carefully any instructions from your health care team about:

• Alcohol—Drinking alcohol may cause severe low blood sugar. Discuss this with your health care team.
• Other medicines—Do not take other medicines during the time you are taking acarbose (the active ingredient contained in Precose) unless they have been discussed with your doctor. This especially includes nonprescription medicines such as aspirin, and medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems.
• Counseling—Other family members need to learn how to prevent side effects or help with side effects if they occur. Also, patients with diabetes may need special counseling about diabetes medicine dosing changes that might occur because of lifestyle changes, such as changes in exercise and diet. Furthermore, counseling on contraception and pregnancy may be needed because of the problems that can occur in patients with diabetes during pregnancy.
• Travel—Keep a recent prescription and your medical history with you. Be prepared for an emergency as you would normally. Make allowances for changing time zones and keep your meal times as close as possible to your usual meal times.

In case of emergency—There may be a time when you need emergency help for a problem caused by your diabetes. You need to be prepared for these emergencies. It is a good idea to wear a medical identification (ID) bracelet or neck chain at all times. Also, carry an ID card in your wallet or purse that says that you have diabetes and a list of all of your medicines.

Acarbose does not cause hypoglycemia (low blood sugar). However, low blood sugar can occur if you take acarbose with another type of diabetes medicine, delay or miss a meal or snack, exercise more than usual, drink alcohol, or cannot eat because of nausea or vomiting. Symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out). Different people may feel different symptoms of low blood sugar. It is important that you learn which symptoms of low blood sugar you usually have so that you can treat it quickly.

Symptoms of low blood sugar include anxiety; behavior change similar to being drunk; blurred vision; cold sweats; confusion; cool, pale skin; difficulty in thinking; drowsiness; excessive hunger; fast heartbeat; headache (continuing); nausea; nervousness; nightmares; restless sleep; shakiness; slurred speech; or unusual tiredness or weakness.

If symptoms of low blood sugar occur, eat glucose tablets or gel or honey, or drink fruit juice to relieve the symptoms. Table sugar (sucrose) or regular (nondiet) soft drinks will not work. Also, check your blood for low blood sugar. Glucagon is used in emergency situations when severe symptoms such as seizures (convulsions) or unconsciousness occur. Have a glucagon kit available, along with a syringe and needle, and know how to use it. Members of your household also should know how to use it.

Hyperglycemia (high blood sugar) may occur if you do not take enough or skip a dose of your antidiabetic medicine, overeat or do not follow your meal plan, have a fever or infection, or do not exercise as much as usual.

Symptoms of high blood sugar include blurred vision; drowsiness; dry mouth; flushed, dry skin; fruit-like breath odor; increased urination; ketones in urine; loss of appetite; stomachache, nausea, or vomiting; tiredness; troubled breathing (rapid and deep); unconsciousness; or unusual thirst.

If symptoms of high blood sugar occur, check your blood sugar level and then call your doctor for instructions.

Common side effects of Precose

Some side effects of acarbose may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects of Precose

Along with its needed effects, acarbose may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

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

For healthcare professionals

Applies to acarbose: oral tablet.

General adverse events

The most frequently reported adverse events include abdominal pain, diarrhea, and flatulence.^[Ref]

Gastrointestinal

• Very common (10% or more): Abdominal pain (19%), diarrhea (31%), flatulence (74%)
• Uncommon (0.1% to 1%): Nausea,, vomiting, dyspepsia
• Postmarketing reports: Ileus/subileus, pneumatosis cystoides intestinalis^[Ref]

In large-scale clinical trials, a majority of patients have complained of gastrointestinal (GI) side effects. GI side effects usually developed within the first few weeks of therapy, were usually mild to moderate in severity, and typically decreased over time. The most common GI side effects were due to the fermentation of unabsorbed carbohydrates and resultant gas production. The severity of GI symptoms may be decreased by dosage reduction and by avoidance of gas-producing foods and sucrose.

There have been rare postmarketing reports of pneumatosis cystoides intestinalis associated with alpha-glucosidase inhibitors including this drug. If suspected, discontinue therapy and perform appropriate diagnostic testing.^[Ref]

Hepatic

• Very common (10% or more): Serum transaminase elevations (14%)
• Postmarketing reports: Fulminant hepatitis with fatal outcome, jaundice and/or hepatitis and associated liver damage^[Ref]

Treatment-emergent elevations of AST and ALT to greater the upper limit of normal, greater than 1.8 x ULN) and greater than 3 x ULN have been observed in 14%, 6%, and 3% of patients in studies of up to 12 months with doses up to 300 mg 3 times a day. The elevations were more common in women and generally asymptomatic and reversible. Additionally, these elevations appear to be dose-related.

International postmarketing experience: There have been 62 reports of of serum transaminase elevations to greater than 500 international units/liter, 29 were associated with jaundice. Of these 62 cases, 41 were receiving treatment with 100 mg 3 times a day or greater, 33 of 45 patients for whom weight was reported weighed less than 60 kg. In the 59 cases for which follow-up was provided, 55 had improvement or resolution of hepatic abnormalities with drug discontinuation, in 2 cases the hepatic abnormalities remained unchanged. Five cases of fulminant hepatitis with fatal outcome have been reported in Japan.^[Ref]

Hematologic

• Frequency not reported: Small reductions in hematocrit
• Postmarketing reports: Thrombocytopenia^[Ref]

Dermatologic

• Frequency not reported: Acute generalized exanthematous pustulosis^[Ref]

Hypersensitivity

• Postmarketing reports: Hypersensitivity skin reactions (e.g. rash, erythema, exanthema, urticaria)^[Ref]

Cardiovascular

• Postmarketing reports: Edema^[Ref]

Metabolic

• Frequency not reported: Hypoglycemia, low serum calcium, low plasma vitamin B6 levels^[Ref]

This drug when administered as monotherapy should not cause hypoglycemia, but when administered with other agents, it may increase the potential for hypoglycemia. Low serum calcium and low plasma vitamin B6 levels were associated with use of this drug, however, they are thought to be spurious or of no clinical significance.^[Ref]

See also:

Further information

Precose side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer