Glibenclamide

Allopathic
Indications

FDA-Approved Indications:

  • Type 2 Diabetes Mellitus (T2DM):
    As an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes.

Clinically Accepted Off-Label Uses:

  • Gestational Diabetes Mellitus (GDM): Sometimes used as an alternative to insulin, although insulin is preferred; careful monitoring is required.
  • Combination Therapy: May be used in combination with metformin or insulin for patients inadequately controlled on monotherapy.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

Dosage & Administration

Adults (Type 2 Diabetes Mellitus):

  • Initial dose: 2.5 mg once daily, taken with breakfast or first main meal.
  • Titrate by 2.5 mg at weekly intervals depending on glycemic response.
  • Maintenance dose: 2.5–10 mg daily (single or divided dose).
  • Maximum dose: 20 mg per day.

Elderly or Debilitated Patients:

  • Start with 1.25–2.5 mg once daily to minimize hypoglycemia.

Renal or Hepatic Impairment:

  • Lower doses required.
  • Avoid use in severe impairment due to risk of prolonged hypoglycemia.

Pediatric Use:

  • Safety and efficacy not established; not recommended.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

Mechanism of Action (MOA)

Glibenclamide is a second-generation sulfonylurea.

  • It binds to sulfonylurea receptors (SUR1) on pancreatic β-cells.
  • This causes closure of ATP-sensitive potassium channels, leading to depolarization.
  • Calcium influx triggers insulin release from β-cells.
  • The increased insulin lowers blood glucose by enhancing glucose uptake and utilization.
Pharmacokinetics
  • Absorption: Well absorbed orally; peak plasma concentration within 2–4 hours.
  • Distribution: Highly protein-bound (~99%).
  • Metabolism: Extensively metabolized in the liver (CYP3A4, CYP2C9).
  • Excretion: Primarily via bile (metabolites) and partly in urine.
  • Half-life: 4–10 hours, but hypoglycemic effect may last up to 24 hours.
Pregnancy & Lactation
  • Pregnancy: FDA Pregnancy Category C. Insulin is preferred for diabetes management during pregnancy; glibenclamide may cross the placenta in small amounts.
  • Lactation: Not recommended; drug and/or metabolites may pass into breast milk and cause hypoglycemia in infants.
Therapeutic Class
  • Antidiabetic agent – Sulfonylurea (2nd generation).
Contraindications
  • Hypersensitivity to sulfonylureas or sulfonamides.
  • Type 1 diabetes mellitus.
  • Diabetic ketoacidosis (DKA) with or without coma.
  • Severe renal or hepatic impairment.
  • Pregnancy and lactation (relative contraindication).
Warnings & Precautions
  • Hypoglycemia risk is significant, especially in elderly, malnourished, or renally impaired patients.
  • Use with caution in patients with adrenal, pituitary insufficiency, or thyroid disorders.
  • May cause secondary failure over time as pancreatic β-cell function declines.
  • Avoid alcohol – may potentiate hypoglycemia.
  • Regular blood glucose and HbA1c monitoring required.
Side Effects

Common:

  • Hypoglycemia (most frequent, dose-dependent).
  • Nausea, vomiting, abdominal discomfort.
  • Weight gain.

Serious/Rare:

  • Severe prolonged hypoglycemia.
  • Hematologic effects: leukopenia, agranulocytosis, thrombocytopenia.
  • Hepatotoxicity, cholestatic jaundice.
  • Allergic skin reactions (rash, urticaria, photosensitivity).
Drug Interactions
  • Increased hypoglycemia risk:
    – Insulin, other sulfonylureas, metformin, salicylates, sulfonamides, MAO inhibitors, beta-blockers, warfarin, alcohol.
  • Reduced effect (hyperglycemia):
    – Corticosteroids, thiazide diuretics, phenytoin, rifampicin, thyroid hormones, oral contraceptives.
  • Beta-blockers may mask hypoglycemia symptoms (tachycardia, tremor).
Recent Updates or Guidelines
  • Modern guidelines (ADA, EASD) recommend sulfonylureas as a second-line or third-line therapy for T2DM when metformin is insufficient or contraindicated.
  • Due to hypoglycemia risk, newer agents (DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 analogs) are often preferred.
  • Still widely used in low-resource settings due to cost-effectiveness.
Storage Conditions
  • Store at 15–30°C, in a cool, dry place.
  • Protect from light and moisture.
  • Keep out of reach of children.