Maximum Recommended Dose of Gliclazide
The maximum daily dose of gliclazide depends on the formulation: 120 mg/day for the modified-release (MR) formulation and 320 mg/day for the immediate-release (IR) formulation. 1, 2
Formulation-Specific Dosing Limits
Modified-Release (MR) Formulation
- The American Diabetes Association recommends starting with one 60 mg tablet daily, with a maximum daily dose of 120 mg per day 1
- This once-daily formulation provides progressive drug release over 24 hours, matching the glycemic profile in type 2 diabetes 3
- Clinical trials have demonstrated efficacy with gliclazide MR 30-120 mg once daily over extended treatment periods 3, 4
Immediate-Release (IR) Formulation
- The American Diabetes Association recommends an initial dose of 40-80 mg daily for the immediate-release formulation, with a maximum daily dose of 320 mg 2
- Doses exceeding 80 mg should be divided into two doses rather than given as a single daily dose 2
- Research confirms that gliclazide IR can be titrated up to 320 mg/day in divided doses when needed for glycemic control 3, 5
Important Clinical Considerations
Dose Escalation Limitations
- Further dose increases beyond 15-20 mg daily (for glipizide, a related sulfonylurea) rarely provide meaningful benefit and increase hypoglycemia risk, suggesting a similar ceiling effect may apply to gliclazide 6
- When comparing uptitration of gliclazide from 160 mg to 320 mg versus adding another agent, the uptitration strategy showed less glycemic improvement, with only 22% of patients achieving HbA1c <7% 5
Renal Impairment Adjustments
- For patients with mild to moderate renal impairment, no specific dose adjustment is required for gliclazide 2
- For patients with GFR <30 mL/min/1.73 m², gliclazide may need dose reduction but can still be used with caution, as it is primarily metabolized by the liver 1
Safety Profile at Maximum Doses
- Clinical trials using maximum doses (120 mg MR or 320 mg IR) showed low hypoglycemia rates of approximately 4.8 episodes per 100 patient-years, with no severe episodes requiring third-party assistance 3, 4
- Confirmed hypoglycemia with blood glucose <3 mmol/L occurred in only 3.7% of patients on gliclazide MR at therapeutic doses 7