Makindo Medical Notes

💊 Glibenclamide is a long-acting sulphonylurea used in the treatment of type 2 diabetes mellitus (T2DM). Although effective, it is now less commonly prescribed due to its prolonged action and higher risk of hypoglycaemia compared to shorter-acting sulphonylureas. 👉 Always check the BNF for latest prescribing guidance.

⚙️ Mode of Action

• Stimulates pancreatic β-cell receptors → increased insulin release.
• Inhibits hepatic gluconeogenesis (↓ liver glucose output).
• Overall: lowers blood glucose by ↑ insulin & ↓ endogenous glucose production.

📌 Indications

• Type 2 Diabetes Mellitus (T2DM) – when metformin alone is insufficient.

💊 Dose

• Typical: 5 mg mane with food (max 15 mg/day).
• Start low and titrate carefully in elderly or frail patients due to risk of hypoglycaemia.

🔗 Interactions

• ❗ Increased risk of hypoglycaemia when combined with:
  • Chloramphenicol, Sulphonamides, Co-trimoxazole
  • Warfarin
  • Fibrates
• Alcohol 🍷 can also potentiate hypoglycaemia (“disulfiram-like reaction”).

⚠️ Cautions

• Obesity → metformin preferred as first-line.
• Consider switching to variable rate IV insulin infusion (VRIII) in acute illness, perioperatively, or if patient is NBM.
• Higher risk of prolonged hypoglycaemia in elderly patients or those with renal/hepatic impairment.

⛔ Contraindications

• Type 1 Diabetes (requires insulin).
• Severe renal or hepatic impairment.
• Pregnancy & breastfeeding (insulin preferred).
• See full BNF list for other specific contraindications.

💥 Side Effects

• 🤕 Hypoglycaemia – especially in elderly or missed meals.
• ⚖️ Weight gain.
• 😣 GI upset (nausea, diarrhoea).
• 🌸 Rash, pruritus (allergic reactions).
• 🩸 Rare: blood dyscrasias (e.g., agranulocytosis), liver toxicity.

🧠 Clinical Pearls

• Glibenclamide is long-acting (up to 24h) → increased risk of severe, prolonged hypos compared with shorter-acting sulphonylureas (e.g., gliclazide).
• In frail elderly, consider safer alternatives (e.g., gliclazide or DPP-4 inhibitors).
• Always advise patients on the “hypo rules”: carry glucose tablets/sweets, avoid skipping meals, and monitor blood glucose regularly.

📚 References

• BNF – Glibenclamide
• NHS – Glibenclamide Information