Acarbose Side Effects: Common & Rare Adverse Reactions Explained

Acarbose (Precose) is a drug that is used along with diet and exercise to manage blood sugar in people with type 2 diabetes. 

It is a prescription-only oral medication that belongs to a class of drugs called alpha-glucosidase inhibitors.

Precose works by reducing the activity of certain enzymes in your intestines that break down carbohydrates into simple sugars. 

This may reduce the absorption of carbohydrates and help in managing blood sugar levels after a meal.

Like many drugs, acarbose may have some undesirable side effects.

In this article, we tell you everything you need to know about acarbose’s side effects, including why they may occur, how long they may last, and how to reduce Precose’s adverse reactions.

What are the side effects of acarbose?

Some possible side effects of using acarbose tablets include:

1) Digestive tract symptoms

According to clinical trials, the most common side effects of acarbose are related to the gastrointestinal system. 

These symptoms occur because the drug prevents the absorption of carbohydrates. The unabsorbed carbs get fermented in the digestive tract and cause increased gas production. 

This can lead to:

  • Abdominal discomfort or pain
  • Gas or bloating
  • Mild diarrhea
  • Flatulence

Nausea, vomiting, and dyspepsia are also possible but less common digestive side effects.

2) Allergic reactions

Some individuals may experience a mild allergic skin reaction when using acarbose. Signs of allergy include a rash, redness, and itching.

Having a serious allergic reaction to the drug is also possible, but it rarely occurs. 

Symptoms include difficulty breathing, severe dizziness, hives, and swelling of your face, tongue, lips, or throat. 

Seek medical attention immediately if you experience any of these symptoms while using Precose.

3) Low blood sugar

While acarbose does not typically cause hypoglycemia on its own, there is a risk when combined with other diabetic drugs.

Symptoms of hypoglycemia include feeling weak or dizzy, a fast heartbeat, shakiness, hunger, blurred vision, headache, and sweating.

Treating low blood sugar from acarbose

Acarbose slows down the breakdown of table sugar. So, using this would not work well to treat hypoglycemia caused by the drug. 

Instead, you should use sources of dextrose (D-glucose). Glucose tablets or gels are the best sources to carry around. 

If you don’t have them, you can use honey, raisins, dates, or plums.

In the case of severe hypoglycemia, you would need a glucagon injection to quickly release glucose into your blood. 

Speak with your doctor about getting an emergency glucagon injection kit. You’ll need to tell the people you live with where you keep the kit and train them on how to respond quickly to an emergency.

Be sure to inform your doctor if you experience hypoglycemia. You’ll need to discuss ways to prevent future episodes.

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How to reduce adverse reactions to acarbose

Although it may not be possible to completely avoid Precose’s side effects, there are some things you can do to prevent them or reduce their severity. 

Here are a few strategies to avoid adverse side effects from acarbose:

1) Don’t chew the tablets

It is best to swallow acarbose tablets whole. If you chew or crush the tablets, more of the drug will be released at a faster rate when it gets to your digestive tract. 

This increases the risk of digestive side effects.  

2) Discuss your allergies

Before you use acarbose, speak with your doctor about any allergies you have because the drug may contain inactive ingredients that you’re allergic to. 

3) Talk to your doctor about possible contraindications

Tell your doctor if you have any history of intestinal problems (e.g., inflammatory bowel disease, ulcers, or obstruction), liver disease, or kidney problems. 

It’s best to avoid taking acarbose if you have a history of these problems because it may affect these organs and cause serious problems.

4) Avoid alcohol

Alcohol can affect control of your blood sugar and lead to both high and low blood sugar.  

It is best to stay away from alcohol when using acarbose and other anti-diabetic drugs because the combination can lead to dangerous drops in your blood sugar.

5) Regularly check your blood sugar

You should routinely check your blood sugar, as directed by your health care provider. 

That way, you can monitor how well your sugar is being controlled and catch episodes of hypoglycemia earlier. 

Learning – and teaching the people you stay with – the symptoms of hypoglycemia will also help you catch and treat an episode promptly.

6) Take the prescribed dosage

Taking more than what is prescribed increases the risk of side effects, particularly digestive symptoms. 

In the case of an acarbose overdose, contact emergency medical services immediately.

7) Watch out for acarbose drug interactions

Drug interactions can change how a drug works and increase your risk of side effects. 

Some drugs that can interact with acarbose include:

  • Beta-blockers like metoprolol and propranolol
  • Glaucoma eye drops like timolol
  • Contraceptive pills
  • Diuretics like furosemide and hydrochlorothiazide
  • Anticonvulsants like Dilantin
  • Steroids like prednisolone and hydrocortisone
  • Thyroid medications like levothyroxine

The above list is not a complete list of all the medications that may interact with acarbose. Be sure to inform your doctor about all the drugs you are taking, including supplements and herbal medications.  

How long do Precose’s side effects last?

Digestive side effects of acarbose may occur during the first few days to weeks after you start using the medication. They usually decrease as your body adjusts to the drug. 

The symptoms are normally mild to moderate in severity. If they persist beyond a few weeks or they become worse, seek medical advice immediately.

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Are there any long-term side effects of Precose?

In some cases, acarbose may cause rare and longer-lasting side effects. These include:

Pneumatosis cystoides intestinalis

This refers to a condition in which gas-filled cysts form on the wall of your intestines. 

It is a rare complication that may occur during acarbose treatment and can lead to serious problems like blockage, perforation of your intestines, and bleeding.

Symptoms of pneumatosis cystoides intestinalis include persistent diarrhea, blood and/or mucus in stool, and constipation.

Liver damage

Damage to the liver is another rare side effect of acarbose. Symptoms include pain in the upper right side of the abdomen, yellowing of the eyes and skin, fatigue, nausea, itchy skin, swelling of the abdomen, dark urine, pale stools, etc. 

Seek medical attention immediately if you experience these symptoms.

How do you feel when stopping acarbose?

There are two main things you may experience if you stop taking acarbose:


If you stop acarbose without switching to another diabetes medication, your blood sugar may rise. 

This high blood sugar can lead to symptoms such as thirst, frequent urination, blurred vision, and headache. 

Uncontrolled blood sugar can lead to long-term complications like kidney problems, nerve issues, and cardiovascular disease.

No more side effects

If you were experiencing side effects when taking acarbose, they should stop once it has been cleared out of your system. Side effects like liver damage may be long-lasting, however.

Before discontinuing acarbose, consult with your doctor for a proper plan, especially if transitioning to an alternative medication.


Acarbose is an alpha-glucosidase inhibitor that acts on certain enzymes in the intestines to slow down the breakdown and absorption of carbohydrates. 

Because of how it works, the most common side effects of Precose are digestive symptoms like abdominal discomfort, bloating, and flatulence. 

Other possible side effects of acarbose include low blood sugar (when used with other diabetes medications) and allergic reactions.

Some ways to prevent or reduce the side effects include swallowing the tablets whole, taking the prescribed dosage, avoiding alcohol, and watching out for drug interactions. 

The side effects are usually mild and resolve within days to weeks of using the drug. Speak with your doctor if the side effects persist or become worse. 

Also, watch out for symptoms like blood/mucus in your stool, yellowing of your eyes or skin, abdominal swelling, dark urine, and pale stools.

Avoid using this drug if you have a history of liver disease, intestinal obstruction, or ulcers. If you have further questions about the side effects of acarbose, speak with your healthcare provider.

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  1. McIver LA, Preuss CV, Tripp J. Acarbose. [Updated 2022 Sep 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
  2. Kalra S. Alpha glucosidase inhibitors. J Pak Med Assoc. 2014 Apr;64(4):474-6. PMID: 24864650. 
  3. Hanefeld M, Schaper F. Acarbose: oral anti-diabetes drug with additional cardiovascular benefits. Expert Rev Cardiovasc Ther. 2008 Feb;6(2):153-63. doi: 10.1586/14779072.6.2.153. Erratum in: Expert Rev Cardiovasc Ther. 2009 Mar;7(3):330. PMID: 18248270.
  4. Singla RK, Singh R, Dubey AK. Important Aspects of Post-Prandial Antidiabetic Drug, Acarbose. Curr Top Med Chem. 2016;16(23):2625-33. doi: 10.2174/1568026616666160414123500. PMID: 27086787.
  5. Im J, Anjum F. Pneumatosis Intestinalis. [Updated 2023 Apr 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.

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