Glibenclamide Oral: Dosing and Precautions

Therapeutic action

Sulfonylurea antidiabetic.

Indications

• Second-line treatment of type 2 diabetes in patients under 60 years as monotherapy when metformin is not tolerated or contraindicated.
• In combination with metformin when glycaemic control is inadequate with metformin alone.

Forms and strengths

• 5 mg scored tablet.

Dose and duration

Adult:

• Week 1: 2.5 mg once daily in the morning.
• Week 2: 5 mg once daily in the morning.
• Increase if necessary in increments of 2.5 mg weekly according to blood glucose levels.
• The usual dose is 5 mg 2 times daily, maximum 15 mg daily.

Contra-indications, adverse effects, precautions

• Do not administer in the event of allergy to sulfonamides, type 1 diabetes, juvenile diabetes, ketoacidosis, or severe renal or hepatic impairment.
• May cause hypoglycaemia, especially in patients over 60 years, gastrointestinal disturbances, weight gain, and rarely allergic reactions.
• Monitor combination with diuretics, ACE inhibitors, NSAIDs, azole antifungals, ciprofloxacin, erythromycin, and co-trimoxazole because hypoglycaemic effect may be enhanced.
• Rifampicin decreases hypoglycaemic effect.
• Corticosteroids, hydrochlorothiazide, salbutamol, and chlorpromazine may increase blood glucose.
• Avoid combination with alcohol because of antabuse reaction and risk of hypoglycaemia.
• Pregnancy: avoid. Insulin is the drug of choice for type 2 diabetes in pregnant women.
• Breast-feeding: contraindicated.