Sulfonylureas: Brand Comparison for Type 2 Diabetes

When to consider sulfonylureas over metformin or vice versa

Sulfonylureas are a class of medications used to manage type 2 diabetes. The drugs work by encouraging the release of insulin from the pancreas to help lower blood sugar levels.

This article discusses everything you need to know about how sulfonylureas work for type 2 diabetes and what to expect when taking the drug.

Man talking to doctor about medication

Courtney Hale / Getty Images

Effect of Sulfonylureas on Type 2 Diabetes

People with type 2 diabetes must manage their blood sugar levels because their bodies do not respond to insulin. As a result, sugar levels build up in the blood and cause health issues.

Sulfonylureas stabilize blood sugar by helping the pancreas create more insulin. Sulfonylureas stimulate pancreatic β-cells, the cells in the pancreas that produce and release insulin. Increased insulin levels in the body improve the transfer of blood sugar into cells. Sulfonylureas also reduce the amount of insulin cleared from the body by the liver, which prevents high blood sugar.

Can People With Type 1 Diabetes Take Sulfonylureas?

In people with type 1 diabetes, the body does not produce insulin. Because of that, sulfonylureas can only be used for those with type 2 diabetes.

Sulfonylureas vs. Metformin

Metformin is another drug that treats diabetes. It works similarly to sulfonylureas by helping the body handle insulin more appropriately. However, Metformin belongs to a different class of medicines known as biguanides. Biguanides work by increasing how well insulin works as opposed to keeping more insulin in the body.

Although both drugs treat type 2 diabetes, Metformin is often the first-choice therapy and is a better choice for people with health complications such as reduced kidney function.

In some cases, the two drugs will be taken in a combinational approach to help better control diabetes and blood sugar levels.

The safety level of both medications depends highly on a person’s health history, any complications or health issues they have outside of type 2 diabetes, and their healthcare provider’s recommendations. That said, some research has found that taking sulfonylureas can increase the risk of cardiovascular complications over metformin use.

How to Choose

Your healthcare provider will provide a medication recommendation based on their knowledge of your current state of health.

Brand-Name and Generic Types

Many different medications fall under the umbrella of sulfonylureas.

Brand Name and Generic Types of Sulfonylureas
Generic Name Brand Name 
Glimepiride  Amaryl
Glipizide GlipiZIDE XL, Glucotrol, Glucotrol XL
Glyburide Micronase, Glynase PresTab, Glynase, Glycron, DiaBeta

Potential Side Effects

Though sulfonylureas are well-tolerated by many, some known side effects can develop when taking the drug. Those side effects can include:

  • Hypoglycemia (dangerously low blood sugar)
  • A worsening insulin response
  • Weight gain
  • Nausea
  • Feeling full in the upper abdomen
  • Heartburn
  • Light-colored stools
  • Pain in the upper-right area of the stomach
  • Unusual bleeding or bruising
  • Diarrhea
  • Sore throat
  • Swelling of the eyes, face, lips, tongue, or throat
  • Skin reactions that mimic allergies
  • Sensitivity to the sun
  • Severe skin inflammation that covers the entire body
  • An impaired liver function could lead to jaundice, hepatitis, and liver failure
  • Changes in how the heart functions
  • An increased risk of heart disease and stroke

Hypoglycemia and Sulfonylureas

Hypoglycemia occurs when blood sugar levels become dangerously low. In people taking sulfonylureas, too much insulin can build up in the body and cause low blood sugar levels. People can experience a fast heartbeat, nervousness or anxiety, irritability or confusion, and dizziness when this happens. In the most severe cases, coma, brain damage, and death can occur from hypoglycemia.

Drug Interactions 

Some medications should not be taken at the same time as sulfonylureas or hold a higher risk for adverse effects, such as:

  • Aspirin
  • Medications that reduce blood pressure, such as beta-blockers
  • Clarithromycin, an antibiotic
  • Colesevelam, a cholesterol-lowering drug
  • Antifungal medications
  • Non-steroidal anti-inflammatory drugs (NSAIDs), such as Advil
  • Quinolone antibiotics
  • Sulfamethoxazole, an antibiotic
  • Topiramate, an anti-seizure medication
  • Warfarin, a blood thinner

Medications, Supplements, and Sulfonylureas

When you are about to begin taking sulfonylureas, be sure to tell your healthcare provider about all medications and supplements you take, whether they're prescribed or over the counter (OTC). It’s vital to ensure that you do not experience adverse effects because of drug interactions.


Sulfonylureas are a class of type 2 diabetes drugs. They are considered safe and effective and stabilize blood sugar by increasing insulin production. Though sulfonylureas are effective, they are not always the first choice when treating type 2 diabetes. Typically, that is metformin. However, the drug given to you will depend highly on your health history and how you respond to medications.

All medications have side effects. Some are more severe than others and require monitoring. If you experience side effects, it’s essential to contact your healthcare provider. They can determine if the medication is still suitable for you based on your experience, how well your blood sugar is managed, and what other drugs or supplements you are taking.

A Word From Verywell

Type 2 diabetes isn’t always easy to cope with, but it can be managed effectively with medications such as sulfonylureas. They are generally considered safe, so if your healthcare recommends them, it’s probably for a good reason.

Managing diabetes early on will significantly reduce your risk of complications caused by untreated high blood sugar levels. If you are unsure about taking this drug, speak to your healthcare provider for more information about whether it's right for you.

Frequently Asked Questions

  • What’s considered the safest sulfonylurea?

    The majority of sulfonylureas are considered safe when taken correctly. However, some come with side effects and an increased risk of harmful complications. According to research, the best sulfonylurea is glimepiride.

  • When should you consider metformin instead of sulfonylureas?

    Your current state of health and health history will play a role in which medication is chosen for managing type 2 diabetes. When choosing between metformin and sulfonylureas, many factors are in play. Typically, metformin is the preferred choice for people who are more at risk for hypoglycemia or those with chronic kidney disease.

  • What are the risks of sulfonylureas in older adults?

    Many older adults may have to be wary of sulfonylureas for managing their type 2 diabetes. That is because the medication can increase the risk of hypoglycemia. Hypoglycemia can cause issues such as dizziness that may increase the risk of falls in older adults and the risk of harmful fractures.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Angelica Bottaro
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.