Alpha glucosidase inhibitor

Alpha glucosidase inhibitors are a type of medication you might need to take if you have type 2 diabetes.

• What are alpha glucosidase inhibitors? 
• How do alpha glucosidase inhibitors work
• How to take alpha glucosidase inhibitors 
• Who can take alpha glucosidase inhibitors?
• Your prescription 
• Side effects of alpha glucosidase inhibitors 
• More information and support 

What are alpha glucosidase inhibitors? 

This medication is sometimes used to help people with type 2 diabetes when changes to diet, or other diabetes medications, have been unable to bring down blood sugar levels to their target range.   

There is only one tablet in this drug class called acarbose, which has the brand name Glucobay.  

How do alpha glucosidase inhibitors work? 

Alpha glucosidase inhibitors work by slowing down the digestion of starchy foods like potatoes, bread and rice from the gut. This means that blood sugar levels rise more slowly after meals.  

How to take alpha glucosidase inhibitors 

Alpha glucosidase inhibitors should always be taken before a meal. You can chew a tablet with the first mouthful of food or swallow it whole with a little water. 

Always take alpha glucosidase inhibitors exactly as your healthcare professional has told you. The Patient Information Leaflet inside the box will tell you how to take it but always check with a doctor or pharmacist if you are not sure. 

Who can take alpha glucosidase inhibitors? 

Adults over the age of 18 years with type 2 diabetes can take alpha glucosidase inhibitors. 

Who can’t take alpha glucosidase inhibitors? 

Some medications might not be suitable for some people, which might be because of medical conditions or other reasons:   

• Alpha glucosidase inhibitors might not be suitable for you if you have a medical condition that affects how you absorb or digest food, or if you have inflammation or swelling of the bowel or a large hernia; 
• If you have kidney disease you might not be able to take an alpha glucosidase inhibitor, but this will depend on the stage of your kidney disease; 
• If you have liver disease you might also not be able to have it depending on the stage of your liver disease; 
• You may need to temporarily stop taking this medication if you're going to have an operation; 
• You should not use an alpha glucosidase inhibitor if you are pregnant of breastfeeding. If you’re planning a pregnancy speak with a healthcare professional if you are using this medication.    

When you start a new medication always check with your healthcare team that it’s suitable for you to take. 

Your prescription 

Your healthcare team should explain your prescription to you but it's important to make sure you ask if you don't feel you know enough.   

And make sure you talk to your GP or your diabetes team if you struggle to take your medication. They might be able to help by giving you a different dose. 

In England, if you need to take any medication to manage your diabetes, your prescriptions will be free. Ask your healthcare team about a prescription exemption certificate if you don't have one, to make sure you don't get charged for your medication. Prescriptions are already free for everybody in the rest of the UK, so you shouldn't pay for your acarbose. 

Side effects of alpha glucosidase inhibitors 

Like all medications, alpha glucosidase inhibitors can cause side effects. But when side effects are listed as common in the Patient Information Leaflet, it doesn’t mean that everyone who takes the medication will get them.   

The information about side effects is based on the likelihood of people having them. For example, if a side effect is very common then it can affect more than one in ten people, and if a side effect is very rare then it affects fewer than one in 10,000 people.   

Because medicines can affect people differently, your healthcare team will speak to you about what’s best for you and discuss any side effects.  

Upset tummy or tummy pain 

In the first two or three days of taking acarbose it’s common to have flatulence or wind, feel a rumbling in your stomach, or feeling full or cramps in the tummy. Some people also have diarrhoea and pain in the tummy.  

Let your healthcare team know if these side effects carry on for more than two or three days – particularly if they are severe, or if you have diarrhoea. 

Risk of low blood sugar 

Alpha glucosidase inhibitors do not usually cause blood sugar levels to become too low, also known as hypoglycaemia or hypos, when taken on their own. But hypos can happen when you take acarbose with other diabetes medications such as insulin or a sulphonylureas. 

If you take acarbose, treatment for hypos should be with a type of sugar called glucose which includes jelly babies, glucose tablets and glucose liquid, but not sucrose which is a table sugar often added to processed foods and drinks. This is because acarbose slows down how quickly sugar like sucrose is digested which means that it would take longer to recover from a hypo. 

These are not all the side effects. You will find a full list of known side effects in the Patient Information Leaflet. This comes in the medication box. 

It’s also important that you take individual advice from your healthcare team before starting acarbose treatment and report any side effects to your healthcare professionals, if you have any.  

You can also report these side effects to the Yellow Card Scheme, which is the government system used for recording side effects with medicines in the UK.   

More information and support 

Still have more questions? Or is there anything you're not sure about alpha glucosidase inhibitors after reading this page? Contact our helpline on 0345 123 2399. 

You can visit the NHS website for more information on alpha glucosidase inhibitors.