Sulfonylureas Flashcards
What is the mechanism of action of sulfonylureas?
Sulfonylureas bind to the SUR1 receptor on pancreatic beta cells, closing ATP-sensitive potassium channels, leading to calcium influx and insulin release.
What are the first-generation sulfonylureas?
Chlorpropamide, tolbutamide. These have a strong association with SIADH.
What are the second-generation sulfonylureas?
Glyburide, glipizide, glimepiride.
What is the primary indication for sulfonylureas?
Treatment of type 2 diabetes mellitus in patients with functioning pancreatic beta cells.
What is the most common and serious adverse effect of sulfonylureas?
Hypoglycemia, especially in older adults or those with renal/hepatic impairment.
What are the dermatologic adverse effects of sulfonylureas?
Photosensitivity, maculopapular eruptions, purpura, and urticaria.
Which sulfonylurea has the highest risk of hypoglycemia?
Glyburide, due to its long half-life.
What rare adverse effects are associated with sulfonylureas?
Agranulocytosis, hemolytic anemia, and cholestatic jaundice.
In which conditions are sulfonylureas contraindicated?
Type 1 diabetes, pregnancy, lactation, and severe renal or hepatic impairment.
What drugs potentiate hypoglycemia when combined with sulfonylureas?
Aspirin, NSAIDs, sulfonamides, fluoroquinolones, and alcohol.
Which drugs reduce the efficacy of sulfonylureas?
Corticosteroids, thiazides, and beta-blockers.
Why is glipizide preferred over glyburide in elderly patients?
Glipizide has a shorter half-life and lower risk of hypoglycemia.
What side effects are associated with chlorpropamide?
Disulfiram-like reactions and SIADH (syndrome of inappropriate antidiuretic hormone secretion).
How are sulfonylureas metabolized and excreted?
They are metabolized in the liver and excreted by the kidneys.
What should be monitored during sulfonylurea therapy?
Blood glucose levels, signs of hypoglycemia, liver, and kidney function.
