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glyburide (glibenclamide (UK))

Apo-Glyburide (CA), Daonil (UK), DiaBeta, Dom-Glyburide (CA), Euglucon (CA), Gen-Glybe (CA), Glynase PresTab, Micronase, Novo-Glyburide (CA), Nu-Glyburide (CA), PMS-Glyburide (CA), Ratio-Glyburide (CA), Riva-Glyburide (CA), Sandoz Glyburide (CA), Semi-Daonil (UK)

Pharmacologic class: Sulfonylurea

Therapeutic class: Hypoglycemic

Pregnancy risk category B


Increases insulin binding and sensitivity at receptor sites, stimulating insulin release from beta cells in pancreas and reducing blood glucose level. Also decreases production of basal glucose in liver, enhances sensitivity of peripheral tissue to insulin, inhibits platelet aggregation, and causes mild diuresis.


Tablets: 1.25 mg, 2.5 mg, 5 mg

Tablets (micronized): 1.5 mg, 3 mg, 6 mg

Indications and dosages

To control blood glucose in type 2 (non-insulin-dependent) diabetes mellitus in patients who have some pancreatic function and don't respond to diet therapy

Adults: Initially, 2.5 to 5 mg (regular tablets) P.O. daily; range is 1.25 to 20 mg/day as a single dose or in divided doses. Or initially, 1.5 to 3 mg (micronized tablets) P.O. daily, with range of 0.75 to 12 mg/day; give dosages above 6 mg in two divided doses.

Conversion from insulin therapy

Adults: If patient takes less than 20 units of insulin daily, give 2.5 to 5 mg glyburide daily; with insulin dosage of 20 to 40 units/day, give 5 mg glyburide; with insulin dosage above 40 units/day, give 5 mg glyburide daily or 3 mg (micronized tablets) P.O. daily and reduce insulin dosage by 50%.

Dosage adjustment

• Hepatic or renal failure

• Elderly patients


• Hypersensitivity to drug

• Type 1 (insulin-dependent) diabetes

• Severe renal, hepatic, thyroid or other endocrine disease

• Pregnancy or breastfeeding


Use cautiously in:

• mild to moderate hepatic, renal, or cardiovascular disease; impaired thyroid, pituitary, or adrenal function

• infection, stress, or dietary changes

• elderly patients.


Know that micronized glyburide is not bioequivalent to regular glyburide.

• Check baseline creatinine level for normal renal function before giving first dose.

• Give daily dose at breakfast; for patient receiving drug b.i.d., give second dose at dinner.

• Adjust dosage slowly if patient is taking metformin.

Adverse reactions

CNS: dizziness, drowsiness, headache, weakness

CV: increased CV mortality risk

EENT: visual accommodation changes, blurred vision

GI: nausea, vomiting, diarrhea, constipation, cramps, heartburn, epigastric distress, anorexia

Hematologic: aplastic anemia, leukopenia, thrombocytopenia, agranulocytosis, pancytopenia

Hepatic: cholestatic jaundice, hepatitis

Metabolic: hyponatremia, hypoglycemia

Skin: rash, pruritus, urticaria, eczema, erythema, photosensitivity, angioedema

Other: increased appetite


Drug-drug. Androgens (such as testosterone), chloramphenicol, clofibrate, guanethidine, MAO inhibitors, nonsteroidal anti-inflammatory drugs (except diclofenac), salicylates, sulfonamides, tricyclic antidepressants: increased risk of hypoglycemia

Beta-adrenergic blockers: altered response to glyburide, requiring increased or decreased dosage; prolonged hypoglycemia (with nonselective agents)

Calcium channel blockers, corticosteroids, estrogens, hydantoins, hormonal contraceptives, isoniazid, nicotinic acid, phenothiazines, phenytoin, rifampin, sympathomimetics, thiazide diuretics, thyroid preparations: decreased hypoglycemic effect of glyburide

Warfarin: initially increased, then decreased, effects of both drugs

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, cholesterol: increased values

Glucose, granulocytes, hemoglobin, platelets, white blood cells: decreased values

Drug-herbs. Agoral marshmallow, aloe (oral), bitter melon, burdock, chromium, coenzyme Q10, dandelion, eucalyptus, fenugreek: increased hypoglycemic effect

Glucosamine: impaired glycemic control

Drug-behaviors. Alcohol use: disulfiram-like reaction

Patient monitoring

• Monitor blood glucose level, especially during periods of increased stress.

• Monitor CBC and renal function test results.

• If patient is ill or has abnormal laboratory findings, monitor electrolyte, ketone, glucose, pH, lactate dehydrogenase, and pyruvate levels.

• Evaluate cardiovascular status.

Patient teaching

• Advise patient to take daily dose with breakfast (and second dose, if prescribed, with dinner).

• Teach patient how to self-monitor his glucose level as prescribed; tell him to report significant changes.

• Inform patient that he may need supplemental insulin during times of stress or when he can't maintain adequate oral intake.

• Teach patient how to recognize signs and symptoms of hypoglycemia and hyperglycemia.

• Instruct patient to keep sugar source available at all times.

• Encourage patient to drink plenty of fluids.

• Stress importance of diet and exercise in helping to control diabetes.

• Advise patient to wear or carry medical identification stating he has diabetes.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Tell patient he'll undergo regular blood testing during therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.


(glye-byoo-ride) ,


(trade name),


(trade name),

Glynase PresTab

(trade name)


Therapeutic: antidiabetics
Pharmacologic: sulfonylureas
Pregnancy Category: B (Glynase PresTab only)
Pregnancy Category: C


Oral: Control of blood sugar in type 2 diabetes mellitus when diet therapy fails. Requires some pancreatic function.


Lowers blood sugar by stimulating the release of insulin from the pancreas and increasing the sensitivity to insulin at receptor sites.
May also decrease hepatic glucose production.

Therapeutic effects

Lowering of blood sugar in diabetic patients.


Absorption: Well absorbed following oral administration; micronized forms have better absorption.
Distribution: Reaches high concentrations in bile and crosses the placenta.
Metabolism and Excretion: Mostly metabolized by the liver (primarily by CYP2C9).
Half-life: 10 hr.

Time/action profile (hypoglycemic activity)

PO45–60 min1.5–3 hr24 hr


Contraindicated in: Hypersensitivity; Hypersensitivity to sulfonamides (cross-sensitivity may occur); Type 1 diabetes; Diabetic coma or ketoacidosis; Concurrent use of bosentan.
Use Cautiously in: Severe cardiovascular or hepatic disease; Glucose 6-phosphate dehydrogenase deficiency (↑ risk of hemolytic anemia); Geriatric: ↑ sensitivity; dose reduction may be required; Severe renal disease (↑ risk of hypoglycemia); Infection, stress, or changes in diet may alter requirements for control of blood sugar; Impaired thyroid, pituitary, or adrenal function; Malnutrition, high fever, prolonged nausea, or vomiting; Obstetric / Lactation: Safety not established; insulin recommended during pregnancy.

Adverse Reactions/Side Effects

Central nervous system

  • dizziness
  • drowsiness
  • headache
  • weakness


  • constipation
  • cramps
  • diarrhea
  • drug-induced hepatitis
  • dyspepsia
  • ↑ appetite
  • nausea
  • vomiting


  • photosensitivity (most frequent)
  • rashes


  • hypoglycemia (most frequent)

Fluid and Electrolyte

  • hyponatremia


  • aplastic anemia (life-threatening)
  • agranulocytosis
  • hemolytic anemia
  • leukopenia
  • pancytopenia
  • thrombocytopenia


Drug-Drug interaction

↑ risk of elevated liver enzymes when used with bosentan (avoid concurrent use).Ingestion of alcohol may result in disulfiram-like reaction.Effectiveness may be ↓ by concurrent use of diuretics,corticosteroids, phenothiazines,oral contraceptives, estrogens, thyroid preparations, phenytoin, nicotinic acid, sympathomimetics, rifampin, and isoniazid.Alcohol, androgens (testosterone), chloramphenicol, ACE inhibitors, disopyramide, fluoxetine, clarithromycin, fluoroquinolones,MAO inhibitors, NSAIDs (except diclofenac), salicylates , sulfonamides, andwarfarin may ↑ the risk of hypoglycemia.Concurrent use with warfarin may alter the response to both agents (↑ effects of both initially, then ↓ activity); close monitoring recommended during any changes in dose.Beta-adrenergic blockers may mask the signs and symptoms of hypoglycemia.May ↑cyclosporine levels.Colesevelam may ↓ effects; administer glyburide ≥4 hr before colesevelam


The nonmicronized formulation (Diabeta) cannot be used interchangeably with the micronized formulation (Glynase PresTab)
Oral (Adults) DiaBeta (nonmicronized)—2.5–5 mg once daily initially (range 1.25–20 mg/day). Glynase PresTab (micronized)—1.5–3 mg/day initially (range 0.75–12 mg/day; doses >6 mg/day should be given as divided doses). Increments should not exceed 1.5 mg/wk.
Oral (Geriatric Patients) DiaBeta (nonmicronized)—1.25–2.5 mg/day initially; may be ↑ by 2.5 mg/day weekly. Glynase PresTab (micronized)—0.75–3 mg/day; may be ↑ by 1.5 mg/day weekly.

Availability (generic available)

Tablets: 1.25 mg, 2.5 mg, 5 mg
Micronized tablets: 1.5 mg, 3 mg, 6 mg
In combination with: metformin (Glucovance); see combination drugs.

Nursing implications

Nursing assessment

  • Observe for signs and symptoms of hypoglycemic reactions (sweating, hunger, weakness, dizziness, tremor, tachycardia, anxiety). Patients on concurrent beta-blocker therapy may have very subtle signs and symptoms of hypoglycemia.
  • Assess patient for allergy to sulfonamides.
  • Lab Test Considerations: Monitor serum glucose and glycosylated hemoglobin periodically during therapy to evaluate effectiveness.
    • Monitor CBC periodically during therapy. Report ↓ in blood counts promptly.
    • May cause an ↑ in AST, LDH, BUN, and serum creatinine.
  • Overdose is manifested by symptoms of hypoglycemia. Mild hypoglycemia may be treated with administration of oral glucose. Severe hypoglycemia should be treated with IV D50W followed by continuous IV infusion of more dilute dextrose solution at a rate sufficient to keep serum glucose at approximately 100 mg/dL.

Potential Nursing Diagnoses

Imbalanced nutrition: more than body requirements (Indications)
Noncompliance (Patient/Family Teaching)


  • high alert: Accidental administration of oral hypoglycemic agents to non-diabetic adults and children has resulted in serious harm or death.
  • Do not confuse Diabeta with Zebeta.
  • Patients stabilized on a diabetic regimen who are exposed to stress, fever, trauma, infection, or surgery may require administration of insulin.
    • To convert from other oral hypoglycemic agents, gradual conversion is not required. For insulin dose of less than 20 units/day, change to glyburide can be made without gradual dose adjustment. Patients taking 20 or more units/day should convert gradually by receiving glyburide and a 25–30% reduction in insulin dose every day or every 2nd day with gradual insulin dose reduction as tolerated. Monitor serum or glucose and ketones at least 3 times/day during conversion.
  • Oral: May be administered once in the morning or divided into 2 doses. Administer with meals to ensure best diabetic control and to minimize gastric irritation. Do not administer after last meal of the day.
    • Nonmicronized glyburide should not be taken with a meal high in fat. Micronized glyburide cannot be substituted for nonmicronized glyburide Preparations are not equivalent.

Patient/Family Teaching

  • Instruct patient to take medication at same time each day. Take missed doses as soon as remembered unless almost time for next dose. Do not take if unable to eat.
  • Explain to patient that this medication controls hyperglycemia but does not cure diabetes. Therapy is long term.
  • Review signs of hypoglycemia and hyperglycemia with patient. If hypoglycemia occurs, advise patient to drink a glass of orange juice or ingest 2–3 tsp of sugar, honey, or corn syrup dissolved in water or an appropriate number of glucose tablets and notify health care professional.
  • Concurrent use of alcohol may cause a disulfiram-like reaction (abdominal cramps, nausea, flushing, headaches, and hypoglycemia).
  • Encourage patient to follow prescribed diet, medication, and exercise regimen to prevent hypoglycemic or hyperglycemic episodes.
  • Instruct patient in proper testing of serum glucose and ketones. These tests should be closely monitored during periods of stress or illness and health care professional notified if significant changes occur.
  • May occasionally cause dizziness or drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
  • Caution patient to avoid other medications, especially aspirin and alcohol, while on this therapy without consulting health care professional.
  • Caution patient to use sunscreen and protective clothing to prevent photosensitivity reactions.
  • Advise patient to inform health care professional of medication regimen prior to treatment or surgery.
  • Advise patient to notify health care professional promptly if unusual weight gain, swelling of ankles, drowsiness, shortness of breath, muscle cramps, weakness, sore throat, rash, or unusual bleeding or bruising occurs.
  • Insulin is the recommended method of controlling blood sugar during pregnancy. Counsel female patients to use a form of contraception other than oral contraceptives and to notify health care professional promptly if pregnancy is planned or suspected.
  • Advise patient to carry a form of sugar (sugar packets, candy) and identification describing disease process and medication regimen at all times.
  • Emphasize the importance of routine follow-up exams.

Evaluation/Desired Outcomes

  • Control of blood glucose levels without the appearance of hypoglycemic or hyperglycemic episodes.


A brand name for GLIBENCLAMIDE.