- Sulfonylureas increase insulin production and may decrease insulin resistance.
- The most significant side effect of all sulfonylureas is hypoglycaemia (defined as a blood glucose level below 4 mmol/L). Glibenclamide (duration of action 18-24 hours) and glimepiride (duration of action 24 hours but also has active metabolites) may have an increased risk of prolonged hypoglycaemia especially in individuals that may be vulnerable. This includes the elderly or in individuals with renal dysfunction.
- This might also be true of modified release gliclazide (duration of action 16 to 24 hours). Gliclazide immediate release (duration of action 12 to 16 hours) has been shown to have fewer hypoglycaemic episodes that all other sulfonylureas Glipizide (duration of action 6-8 hours) may be a reasonable choice for vulnerable individuals.
- Any blood glucose level under 4mmol/ L is known as a hypoglycaemic episode when being treated with a sulfonylurea.