Medicine & USMLE

Sulfonylureas (Old)

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Sulfonylureas are a drug class including the drugs glimepiride, glyburide, and glipizide. These drugs are used to lower blood sugar, to treat people with type 2 diabetes. An important risk to note is the potential to lower the blood sugar levels too much and cause hypoglycemia, especially in older adults. Patients taking sulfonylureas should avoid alcohol to avoid a disulfiram-like reaction. Importantly, sulfonylureas are sulfa drugs and may therefore cause drug allergies in certain patients - be sure to look out for a history of allergic reactions before giving the drug!

Key Points

  • Sulfonylureas
    • Key drugs
      • Glimepiride
      • Glipizide
      • Glyburide
    • Mechanism
      • Directly stimulates beta cells in the pancreas to release more insulin, thus decreasing blood glucose level
      • Increases tissue response to insulin
      • Decreases glucose production by the liver
    • Clinical Use
      • Hyperglycemia in Type II Diabetes Mellitus
        • Is most effective if administered 30 minutes before a meal
    • SE and AR
      • Hypoglycemia
        • Shakiness
        • Tachycardia
        • Weakness
        • Diaphoresis
        • Use extreme caution in the elderly
      • Avoid alcohol
        • When combined with alcohol, sulfonylureas may cause a disulfiram-like reaction (nausea, vomiting, chills, headache, “hangover” like symptoms)
        • Alcohol can also potentiate the hypoglycemia and lower blood glucose levels even further
      • Hypersensitivity / Allergy (Sulfa Allergy)
        • If a patient has had an allergic reaction to another sulfa-derivative drug (e.g. sulfonamides, thiazide diuretics) the order for sulfonylureas should be questioned
      • Weight gain
      • Photosensitivity