Alpha-Glucosidase Inhibitors

Alpha-glucosidase inhibitors are a class of oral medications that treat Type 2 diabetes. They delay how your body breaks down carbohydrates into simple sugars. This makes sugar enter your blood more slowly and helps prevent blood sugar spikes after meals.

Acarbose and miglitol are the two FDA-approved alpha-glucosidase inhibitors. You take these medications at the start of a meal.

How do alpha-glucosidase inhibitors work?

Alpha-glucosidase inhibitors work by blocking alpha-glucosidase enzymes in your small intestine. These enzymes break down complex carbs into sugar. This slows the sugar down as it enters your bloodstream. You have a slower and steadier rise in blood sugar after meals instead of a sudden spike.

What drugs are alpha-glucosidase inhibitors?

The two drugs available in the U.S. are acarbose (Precose®) and miglitol (Glyset®). Both come in 25, 50 and 100 milligram (mg) tablets that you swallow at the start of a meal. You can take up to three doses per day.

Your healthcare provider will recommend a dosage based on how your blood sugar responds and whether you have side effects. If you have questions about your dosage or think it’s not working, contact your provider.

What are the benefits of alpha-glucosidase inhibitors?

The main benefit is that it can help control blood sugar spikes after meals. It slows down how glucose enters your bloodstream. This can also improve overall blood sugar management.

One of the other benefits is that it works well with many other diabetes medications, like metformin, DPP-4 inhibitors and more.

What are the risks and side effects of alpha-glucosidase inhibitors?

The most common side effects are ones that impact your digestive system. These include:

• Diarrhea
• Excessive gas
• Bloating
• Stomach cramps

These usually improve once your body gets used to the dose. Some providers recommend avoiding meals high in carbohydrates to reduce the side effects.

There is also a small risk of low blood sugar. But this typically only happens when you’re taking alpha-glucosidase inhibitors with insulin or other diabetes medications known to cause low blood sugar. Monitor your blood sugar closely while taking this medication. If low blood sugar happens, you must take glucose (dextrose), not table sugar (sucrose).

Who shouldn’t take alpha-glucosidase inhibitors?

You shouldn’t take this medication if you have digestive conditions like inflammatory bowel disease. People with certain kidney or liver diseases should also be cautious with AGIs. You should avoid this medication if you’re pregnant.

Be sure to share your medical history with your healthcare provider. This should also include any allergies you have or medications you take. They can work with you to decide if these drugs are safe for you.

What drugs interact with alpha-glucosidase inhibitors?

Alpha-glucosidase inhibitors can interact with certain medications. These include:

• Diabetes medications: Taking insulin and sulfonylureas with alpha-glucosidase inhibitors can lower blood sugar too much.
• Digestive enzymes: Drugs and supplements that affect carbohydrate absorption (like digestive enzymes) can weaken the effectiveness of AGIs. Medicines that bind to your gut, like Pepto-Bismol®, can also weaken alpha-glucosidase inhibitors.
• Digoxin: Alpha-glucosidase inhibitors may slow the absorption of digoxin, which is a drug to treat heart conditions.
• Antibiotics: Antibiotics can also irritate your digestive tract. Taking antibiotics with AGIs can worsen side effects like diarrhea and bloating.