Sulphonylureas

Sulphonylureas are older-generation diabetes drugs. They formulaically stimulate the secretion of insulin from the pancreas.

Sulphonylureas are used to manage type 2 diabetes in adults as a phase two or three medicine together with lifestyle management and metformin or other blood sugar-lowering medicines or basal insulin. They can also be used on their own, if metformin or other blood sugar-lowering medicines are not suitable.

In Finland, the use of sulphonylureas tablets has become significantly less common, with new pharmaceutical products becoming available. In Finland (3/2026), only one sulfonylurea preparation is available on the market under special authorisation: glibenclamide.

How do sulphonylureas work?

Sulphonylureas attach themselves to the receptor of the pancreatic beta cell, directly and formulaically increasing the secretion of insulin from the pancreas for the entire 24 hours.

Long-acting glimepiride lowers the blood sugar level after a meal as well as the fasting blood sugar.

For some people, glimepiride stops being effective over the years. It has been suspected that the medicine itself may hasten the body’s inability to produce insulin, but there is no unequivocal proof of this.

In addition to people with type 2 diabetes, there is a specific user group comprised of children with diabetes arising from a rare inborn receptor mutation.

How is sulphonylurea product used?

Sulfonylureas are long‑acting diabetes medications that increase insulin secretion. Their use requires regular meals and planning ahead for physical activity.

Treatment with a sulfonylurea is usually started with a low dose, which can be increased if needed every 1–2 weeks according to blood glucose monitoring and the doctor’s instructions. The maintenance dose is individual. The medication is usually taken once daily before the first proper meal of the day. If breakfast is light, the medication can be taken with lunch instead. In some situations, the dose may be divided into two doses.

Sulfonylureas increase the risk of hypoglycaemia. Therefore, meals should be eaten regularly, carbohydrate amounts at meals should be kept consistent, and physical activity should be planned for (with additional carbohydrates if needed). It is helpful for people using this medication to learn at least a basic estimation of carbohydrate intake.

Possible side-effects of sulphonylureas

All pharmaceutical products involve an individual risk of harmful side effects.

The most common and significant side effect of sulphonylureas is a too low blood sugar. It can be prevented by eating regular meals with regular amounts of carbohydrates and consuming additional food before exercise. This can easily lead to overeating, a fluctuating blood sugar level and weight gain. This is why sulphonylureas are no longer widely used.

Preventing low blood sugar when using glimepiride:

If your meal is delayed, eat a snack.
If you are exercising in the morning, you can wait until lunch before taking the medicine.
The amount carbohydrates in meals should remain fairly regular day after day.
Before exercise, you will need a small snack (containing approx. 20 g of carbs).
You can talk to your doctor about reducing the dose before long exercise sessions.

Take into account that heavy alcohol use increases the risk of low blood sugar.