Classifications: hormone; sulfonylurea; antidiabetic agent;
Therapeutic: antidiabetic; sulfonylurea

Prototype: Glyburide
Pregnancy Category: C


250 mg, 500 mg tablets


Lowers blood glucose by stimulating pancreatic beta cells to secrete insulin.

Therapeutic Effect

Promotes increased effectiveness of endogenous insulin in type 2 diabetes mellitus.


Mild to moderately severe stable type 2 diabetes mellitus. Preferred by some clinicians for patients who also have gout.


Hypersensitivity to sulfonylureas; severe impairment of hepatic, renal, thyroid, or other endocrine function; type 1 diabetics, diabetic ketoacidosis; renal failure, renal impairment; pregnancy (category C), lactation. Safety and effectiveness in children have not been established.

Cautious Use

Renal insufficiency, hepatic impairment, history of hepatic porphyria, elderly.

Route & Dosage

Adult: PO 250 mg/d before breakfast, may be increased by 250–500 mg q5–7d (max: 1.5 g/d); may be dosed b.i.d.


  • Administer daily dose before breakfast.
  • Divided doses are given before breakfast and dinner.
  • Store at 15°–30° C (59°–86° F), unless otherwise directed.

Adverse Effects (≥1%)

Body as a Whole: Generally dose-related. Erythema, urticaria, pruritus, rash, photosensitivity. GI: Nausea, vomiting, epigastric fullness, anorexia, stomach pain or discomfort, heartburn, diarrhea. Hematologic: Agranulocytosis, aplastic anemia, severe hypoglycemia, thrombocytopenia. CNS: Headache, dizziness.

Diagnostic Test Interference

Serum uric acid levels may be appreciably reduced.


Drug: Alcohol may elicit disulfiram reaction; warfarin, aspirin and other salicylates, chloramphenicol, clofibrate, fenfluramine, guanethidine, mao inhibitors, oxytetracycline, phenylbutazone, probenecid, sulfinpyrazone, and sulfonamides may enhance hypoglycemic effects; with diazoxide there is mutual antagonism and effects of both drugs are reduced; thiazide diuretics may exacerbate hyperglycemia, resulting in need for increased acetohexamide doses; phenytoin may decrease effects of acetohexamide; beta-adrenergic blockers may mask symptoms of hypoglycemia. Herbal: Garlic, ginseng may increase hypoglycemic effects.


Absorption: Rapidly from GI tract. Onset: 1 h. Peak: 2–4 h. Duration: 12–24 h. Distribution: Breast milk. Metabolism: In liver to active metabolite. Elimination: 80–95% in urine; 15% in bile. Half-Life: 5–6 h.

Nursing Implications

Assessment & Drug Effects

  • Monitor blood glucose levels closely during first 24–48 h after therapy is initiated or the dose is changed.
  • Monitor for S&S of hypoglycemia/exaggerated hypoglycemic response, particularly in older adults, malnourished, and debilitated patients or those with impaired hepatic, renal function, adrenal, or pituitary insufficiency.
  • Lab tests: Periodic blood glucose, HbA1C, and liver functions.

Patient & Family Education

  • Ingest some form of sugar (e.g., orange juice, dissolved table sugar, corn syrup, honey) if symptoms of hypoglycemia develop, and seek medical assistance.
  • Check blood glucose as prescribed.
  • Do not take any other medication unless approved by physician.
  • Alcoholic beverages may produce a disulfiram-type reaction (see Appendix F).
  • Avoid prolonged direct exposure to sun to prevent photosensitivity reaction.
  • Report dermatologic reactions such as rash or itching.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2022 Last Updated On: 11/21/2022 (0)
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