What is the recommended dosing for gliclazide (sulfonylurea)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 30, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Research

The recommended dosing for gliclazide, a sulfonylurea medication used to treat type 2 diabetes, typically starts at 40-80 mg once daily with breakfast for immediate-release formulations, with a maximum daily dose of 320 mg which can be divided into two doses if exceeding 160 mg daily. For modified-release (MR) formulations, the starting dose is usually 30 mg once daily with breakfast, with a maximum daily dose of 120 mg, although a recent study 1 suggests that the recommended dose for the MR formulation may be increased to 270 mg, with more patients achieving HbA1c goals without a hypoglycemic risk higher than the resulting risk from the recommended IR dose. Dosage adjustments should be made gradually, usually at intervals of at least 2 weeks, based on blood glucose monitoring results. Elderly patients or those with renal impairment may require lower starting doses (20-40 mg for immediate-release or 15 mg for MR) to minimize hypoglycemia risk. Gliclazide works by stimulating insulin secretion from pancreatic beta cells, which helps lower blood glucose levels, as shown in a study where gliclazide increased pulsatile insulin secretion in type 2 diabetes patients 2. It has a medium duration of action compared to other sulfonylureas, providing good glycemic control with relatively lower risk of hypoglycemia, as demonstrated in a comparison with glimepiride where gliclazide MR had significantly fewer confirmed hypoglycemic episodes 3. Patients should take gliclazide at the same time each day and be educated about recognizing and managing hypoglycemia symptoms, as this is the most common side effect. The timing of gliclazide intake is also important, with a study suggesting that taking it 30 minutes before breakfast may optimize its hypoglycemic action 4. Additionally, combining gliclazide with metformin has been shown to be an effective treatment for patients inadequately controlled on sulfonylurea or metformin alone, achieving good glycemic control and improving lipid levels with a better tolerability profile 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.