Sulphonylureas are one of the oldest antidiabetic agents. They act by stimulating beta cells to secrete insulin. That is why they can also lead to hypoglycemia, and are always started at a lower dose. They can rapidly bring down blood sugar levels, and once glucotoxicity is over, they can bring the blood sugar levels dangerously low.
There are two generations of sulfonylureas:
First-Generation Sulfonylureas:
- Tolbutamide
- Dosage: 500 mg to 3000 mg per day (in divided doses)
- Chlorpropamide
- Dosage: 100 mg to 500 mg per day
- Tolazamide
- Dosage: 100 mg to 1000 mg per day (in divided doses)
Second-Generation Sulfonylureas:
- Glipizide
- Immediate-release: 2.5 mg to 40 mg per day
- Extended-release: 5 mg to 20 mg per day
- Glyburide (Glibenclamide)
- Regular: 1.25 mg to 20 mg per day
- Micronized: 0.75 mg to 12 mg per day
- Glimepiride
- Dosage: 1 mg to 8 mg per day
Clinical Considerations:
- Second-generation sulfonylureas are more potent and have a lower risk of side effects compared to first-generation agents.
- Doses should be individualized based on the patient’s glucose levels, renal function, and risk of hypoglycemia.
The duration of action of sulfonylureas varies depending on the specific agent used. Here’s an overview of the durations:
First-Generation Sulfonylureas:
- Tolbutamide
- Duration: 6 to 12 hours (short-acting)
- Chlorpropamide
- Duration: 24 to 72 hours (long-acting)
- Tolazamide
- Duration: 10 to 14 hours (intermediate-acting)
Second-Generation Sulfonylureas:
- Glipizide
- Immediate-release: 12 to 24 hours (intermediate-acting)
- Extended-release: Up to 24 hours (long-acting)
- Glyburide (Glibenclamide)
- Duration: 12 to 24 hours (long-acting)
- Glimepiride
- Duration: 24 hours (long-acting)
Clinical Considerations:
- Shorter-acting sulfonylureas like tolbutamide may require multiple daily dosing to maintain blood glucose control, whereas longer-acting agents like glimepiride and glyburide can be given once daily.
- The duration of action influences the risk of hypoglycemia, with long-acting sulfonylureas having a higher risk due to prolonged insulin secretion.
Glimepride is one of the most popular Sulphonylureas to be used. 1 mg of glimepride lowers 20-30 mg of fasting sugar, and 30-50 mg of postprandial sugar
It is usually used after Metformin, dpp4 inhibitors, and SGLT2 inhibitors options have been exhausted