What are sulfonylurea drugs for treating diabetes?

Sulfonylureas are the oldest class of medications other than insulin used for diabetes treatment. Commonly used sulfonylureas include glipizide (brand name Glucotrol), glyburide (brand names Micronase or Glynase) and glimepiride (brand name Amaryl).  These medicines work by helping the body make more of its own insulin, and, provided the pancreas is still functioning, the medications are often very effective. All of the drugs are available generically, and they are inexpensive. They are most effective in treating the rise in glucose that occurs after you've eaten (postprandial glucose, to use medical terminology). Knowing whether the medications are effective involves doing after-meal finger-stick testing, and if, two hours after eating, the glucose level is higher than desired (under 140 is ideal; up to about 180 may be acceptable), the dose may need to be increased or there may need to be a change in medication.

Sulfonylurea medicines should be taken before eating. If you take the medicines once daily, about 30 minutes before breakfast is best. If you are on a twice-daily schedule, you should take the medicine 30 minutes before breakfast and 30 minutes before dinner. Sometimes confusion arises because the bottle may have a sticker that says, "Take with food." That's actually a bit misleading. The medicine is labeled this way to prevent a low-blood-sugar reaction if you take the medicine and then don't eat anything for several hours.

Sulfonylureas stimulate the beta cells of the pancreas to release more insulin. Sulfonylurea drugs have been in use since the 1950s. Chlorpropamide (Diabinese) is the only first-generation sulfonylurea still in use today. The second generation sulfonylureas are used in smaller doses than the first-generation drugs. There are three second-generation drugs: glipizide (Glucotrol and Glucotrol XL), glyburide (Micronase, Glynase, and Diabeta), and glimepiride (Amaryl). These drugs are generally taken one to two times a day, before meals. All sulfonylurea drugs have similar effects on blood glucose levels, but they differ in side effects, how often they are taken, and interactions with other drugs.