Oral Diabetes Medication


These drugs stimulate beta cells in the pancreas to secrete more insulin. They are classified as either first-generation (drugs that were introduced long ago) or second-generation (newer drugs). If you've been taking oral medication for many years, you may have used chlorpropamide (Diabinese), a popular first-generation sulfonylurea.

Today, most physicians prescribe second-generation drugs such as glimepiride (Amaryl), glipizide (Glucotrol, Glucotrol XL), and glyburide (DiaBeta, Glynase, Micronase), which are stronger than the first-generation sulfonylureas and require lower dosages.

About 85 percent of people with type 2 diabetes who take a sulfonylurea have an initial favorable response. However, the medication gradually loses its effectiveness in more than one quarter of people because beta cells in the pancreas continue to be destroyed. Sulfonylureas rarely work in people with fasting blood glucose levels above 300 mg/dL.

Sulfonylureas can cause weight gain, excessive water retention, and flushing after drinking alcohol. The most common and serious side effect is low blood glucose (hypoglycemia), which typically occurs during the first few months of treatment. If hypoglycemia persists, reducing the dosage often helps. The risk of hypoglycemia is highest in frail, elderly people and in those who are malnourished or have reduced pituitary, adrenal, liver, or kidney function. Alcohol consumption, skipped meals, and exercise also can trigger hypoglycemia in people taking a sulfonylurea.

Publication Review By: Written by: Christopher D. Saudek, M.D.; Simeon Margolis, M.D., Ph.D.

Published: 21 Apr 2009

Last Modified: 10 Mar 2015