Glyburide

A to Z Drug Facts

(glie-BYOO-ride)

DiaBeta, Glynase Pres Tab, Micronase,  Albert Glyburide, Apo-Glyburide, Diabeta, Euglucon, Gen-Glybe, Med-Glybe, Novo-Glyburide, Nu-Glyburide, Penta-Glyburide

Class: Antidiabetic/Sulfonylurea

 Action Decreases blood glucose by stimulating insulin release from pancreas. May also decrease hepatic glucose production and/or increased response to insulin.

 Indications Adjunct to diet to lower blood glucose in patients with non-insulin-dependent diabetes mellitus (type II) whose hyperglycemia cannot be controlled by diet alone; in combination with metformin when diet and glyburide or diet and metformin alone do not result in adequate glycemic control.

 Contraindications Hypersensitivity to sulfonylureas; diabetes complicated by ketoacidosis with or without coma; sole therapy of insulin-dependent diabetes mellitus (type I); diabetes when complicated by pregnancy.

 Route/Dosage

Nonmicronized Form

ADULTS: PO 2.5 to 5 mg/day with breakfast or first main meal.

Patients More Sensitive to Hypoglycemic Drugs (eg, elderly or patients with renal or hepatic dysfunction)

ADULTS: PO 1.25 mg/day initially. Maintenance: 1.25 to 20 mg daily in single or divided doses (patients receiving > 10 mg/day may have better response to twice-daily dosing). Daily doses > 20 mg are not recommended.

Micronized Form (Glynase Pres Tab)

Adults: PO 1.5 to 3 mg/day with breakfast or first main meal. Maintenance: 0.75 to 12 mg/day. Patients receiving > 6 mg/day have more satisfactory response to twice-daily dosing. Daily doses > 12 mg are not recommended.

Conomitant Metformin

ADULTS: PO Add micronized glyburide gradually to the dosing regimen of patients who have not responded to the maximum dose of metformin monotherapy after 4 weeks.

 Interactions

Alcohol: Produces disulfiram-like reaction (facial flushing, headache, breathlessness). Androgens, chloramphenicol, clofibrate, dicumarol, fenfluramine, fluconazole, gemfibrozil, histamine H₂ antagonists, magnesium salts, methyldopa, monoamine oxidase inhibitors, phenylbutazone, probenecid, salicylates, sulfinpyrazone, sulfonamides, tricyclic antidepressants, urinary acidifiers: May increase hypoglycemic effect. Beta-blockers, cholestyramine, diazoxide, hydantoins, rifampin, thiazide diuretics, urinary alkalinizers: May decrease hypoglycemic effect. Ciprofloxacin: A possible interaction between glyburide and ciprofloxacin has been reported, resulting in a potentiation of the hypoglycemic action.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Although issue is controversial, oral sulfonylureas may have increased risk of cardiovascular mortality when compared with patients treated with diet alone. CNS: Dizziness; vertigo. DERM: Allergic skin reactions; eczema; pruritus; erythema; urticaria; morbilliform or maculopapular eruptions; lichenoid reactions; photosensitivity. EENT: Tinnitus. GI: Nausea, epigastric fullness; heartburn. GU: Mild diuresis; mild to moderate elevations in BUN and creatinine. HEMA: Leukopenia; thrombocytopenia; aplastic anemia; agranulocytosis; hemolytic anemia; pancytopenia; hepatic porphyria. HEPA: Cholestatic jaundice; elevated liver function test results. META: Hypoglycemia. OTHER: Disulfiram-like reactions; weakness; paresthesia; fatigue; malaise.

 Precautions

Pregnancy: Category B. Insulin is recommended to maintain blood glucose levels during pregnancy. Prolonged severe neonatal hypoglycemia can occur if sulfonylureas are administered at time of delivery. Lactation: Undetermined. Children: Safety and efficacy not established. Elderly and debilitated patients: Elderly and debilitated patients are particularly susceptible to the hypoglycemic action. Hypoglycemia may be difficult to recognize in elderly patients. Bioavailability: Micronized glyburide (Glynase Pres Tab) and conventional (nonmicronized) glyburide formulations are not equivalent. Hepatic and renal impairment: Use drug with caution; lower doses may be adequate.

 Administration/Storage

• Administer with first main meal of day; patients taking large doses may require twice-daily dosing.
• Dose must be readjusted when switching between micronized and conventional (nonmicronized) formulations; they are not bioequivalent.
• If administering to a pregnant patient, discontinue at least 1 mo before expected date of delivery.
• Store in tightly capped container, and keep out of reach of children.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Note hepatic or renal impairment and the nature of the patient's diabetes (type I vs type II).
• Be aware that hypoglycemia may be difficult to recognize in elderly.
• Test urine for glucose and acetone at least 3 times daily during titration period, unless patient is already testing blood glucose. Report results to health care provider.
• When patients with impaired liver or renal function are receiving this drug, check liver and renal function tests frequently.
• Check blood sugars frequently and observe for symptoms of hypoglycemia or hyperglycemia and report to health care provider.

 Patient/Family Education

• Review with patient dietary guidelines for diabetes.
• Instruct patient to take drug with meals.
• Teach patient to self-monitor urine or blood glucose.
• Inform patient that this drug is not substitute for exercise and diet control and that patient should follow prescribed regimens.
• Instruct patient to inform all health care providers involved in the patient's care that this drug is being taken and to carry medical identification (eg, Medi-Alert bracelet).
• Instruct patient to notify health care provider if symptoms of hypoglycemia occur (fatigue, excessive hunger, profuse sweating, numbness of extremities) or if blood glucose is < 60 mg/dl.
• Tell patient to notify health care provider if symptoms of hyperglycemia occur (excessive thirst or urination, urinary glucose or ketones).
• Instruct patient to report these symptoms to health care provider: Nausea, vomiting, diarrhea, heartburn, sore throat, rash, unusual bruising, or bleeding or other physical complaints.
• Advise patient not to take any medication (including otc) or alcohol without consulting health care provider.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts