Gliclazide Dosing Range
Gliclazide immediate-release is dosed from 80 mg to a maximum of 320 mg daily, administered in divided doses when exceeding 80 mg daily, while the modified-release formulation ranges from 30 mg to 120 mg once daily at breakfast. 1
Immediate-Release Formulation
Starting and Maintenance Dosing
- Initiate at 80 mg once or twice daily depending on glycemic control needs 1
- For twice-daily regimens, administer the full dose in both morning and evening 1
- Maximum daily dose is 320 mg, which must be given in divided doses 1
Dose Titration Strategy
- Increase dosage gradually at monthly intervals based on glycemic response 2
- The typical escalation pattern follows: 80 mg → 160 mg → 240 mg → 320 mg daily 2
- When exceeding 80 mg daily, split into twice-daily administration to optimize glycemic control throughout the day 1
Modified-Release Formulation
Dosing Parameters
- Start at 30 mg once daily taken at breakfast 3, 2
- Titrate upward at monthly intervals: 30 mg → 60 mg → 90 mg → 120 mg 2
- Maximum dose is 120 mg once daily 2, 4
- The once-daily dosing provides effective 24-hour glycemic control 3
Clinical Efficacy Data
- Modified-release formulation achieves similar HbA1c reductions as immediate-release (approximately -1.6%) but with once-daily convenience 2
- Effective across different baseline therapies: diet-failed patients (-2.3% HbA1c reduction), metformin combination (-1.4% reduction), and sulfonylurea-switched patients (-0.6% reduction) 2
Important Safety Considerations
Hypoglycemia Risk Management
- Consider alternative agents with lower hypoglycemia risk (SGLT2 inhibitors or GLP-1 receptor agonists) in high-risk patients before maximizing sulfonylurea doses 1
- The modified-release formulation demonstrates lower hypoglycemia rates (3.7% of patients) compared to other sulfonylureas like glimepiride (8.9%) 5
- Severe hypoglycemic episodes requiring external assistance are rare with gliclazide at recommended doses 4, 5
Special Populations
- Gliclazide maintains a good safety profile in elderly patients and those with impaired renal function, though caution is still warranted 4
- The incidence of hypoglycemic symptoms is approximately 4.8 episodes per 100 patient-years over long-term use 4
Clinical Pitfalls to Avoid
- Do not exceed 320 mg daily for immediate-release or 120 mg daily for modified-release formulations, as efficacy plateaus and adverse effects increase 1, 2
- Avoid single daily doses exceeding 80 mg with immediate-release formulation; always divide higher doses 1
- Modified-release must be taken at breakfast to align with the 24-hour glycemic profile 3