Gliclazide
🍬 Gliclazide is a short-acting sulphonylurea used in the management of Type 2 Diabetes Mellitus (T2DM).
⚠️ Key risk: hypoglycaemia – especially if meals are delayed, missed, or in elderly patients.
👉 Always check the BNF for up-to-date dosing and cautions.
⚙️ Mode of Action
- Stimulates pancreatic β-cell receptors → increased insulin release.
- Inhibits hepatic gluconeogenesis, reducing glucose output from the liver.
- Overall: lowers blood glucose by increasing insulin activity & reducing endogenous glucose production.
📌 Indications
- Type 2 Diabetes Mellitus (T2DM) – when diet and metformin alone are insufficient.
💊 Dose
- 40–80 mg pre-meals (max 320 mg/day, usually in divided doses).
- Modified-release (MR) form also available for once-daily dosing.
🔗 Interactions
- ❗ Increased risk of hypoglycaemia with:
- Chloramphenicol
- Sulphonamides, Co-trimoxazole
- Warfarin
- Fibrates
- Alcohol 🍷 can also exacerbate hypoglycaemia.
⚠️ Cautions
- Renal/hepatic impairment – risk of prolonged hypoglycaemia.
- Obesity – consider metformin first-line (weight-neutral).
- Switch to variable rate IV insulin infusion (VRIII) in acute illness or perioperatively.
- Care in elderly due to higher hypo risk and impaired counter-regulation.
⛔ Contraindications
- Type 1 Diabetes Mellitus.
- Ketoacidosis.
- See full BNF for other contraindications.
💥 Side Effects
- 🍬 Hypoglycaemia – sweating, tremor, confusion, seizures (exam classic).
- ⚖️ Weight gain.
- 😣 GI upset (nausea, diarrhoea).
- 🌸 Rash, hypersensitivity reactions.
- 🩸 Rare: blood disorders (e.g., agranulocytosis, haemolytic anaemia).
- Hepatic toxicity (rare but important).
🧠 Clinical Pearls
- Preferred sulphonylurea in the UK due to its shorter half-life compared with glibenclamide → lower risk of severe hypos.
- Good choice for patients with irregular meal patterns (safer than long-acting agents).
- Patients should always be counselled on “hypo rules” (carry glucose, don’t skip meals, recognise warning signs).
- Monitor HbA1c every 3–6 months and review if frequent hypoglycaemia occurs.
📚 References
