Gliclazide Dosing Recommendations
The recommended dosing for gliclazide is 30-120 mg once daily for the modified-release (MR) formulation, starting at 30 mg and titrating based on glycemic response, while the immediate-release formulation should be initiated at 40-80 mg daily, potentially divided into two doses for amounts exceeding 80 mg. 1, 2
Dosing Guidelines
Modified-Release (MR) Formulation
- Initial dose: 30 mg once daily, taken before breakfast 1
- Dose can be titrated up to a maximum of 120 mg once daily based on glycemic response 1
- The MR formulation shows high bioavailability and its absorption is unaffected by food intake 1
Immediate-Release Formulation
- Initial dose: 40-80 mg daily 2
- For doses exceeding 80 mg daily, divide into two doses (morning and evening) 2
- Maximum daily dose: 320 mg 2
Special Dosing Considerations
Renal Impairment
- No specific dose adjustment is required for gliclazide in mild to moderate renal impairment 3
- For patients with more severe renal impairment, consider alternative medications such as SGLT2 inhibitors or GLP-1 receptor agonists that have demonstrated cardiovascular and renal benefits 2, 3
Elderly Patients
- Start at the lower end of the dosing range (30 mg MR or 40 mg immediate-release) 1
- Gliclazide MR has shown sustained efficacy in elderly patients with reductions in HbA1c similar to those observed in the general population 1
During Ramadan (for Muslim patients)
- For once-daily dosing: Take the full dose before the sunset meal (Iftar) 2
- For twice-daily dosing: Take half the usual morning dose at the predawn meal (Suhur) and the full dose at the sunset meal (Iftar) 2
- Example: If usual dose is 80 mg twice daily, take 40 mg at predawn and 80 mg at sunset 2
Efficacy and Safety Considerations
- Gliclazide MR effectively reduces both fasting and postprandial glucose levels over a 24-hour period 1
- The drug increases insulin secretory burst mass and basal insulin secretion without changing secretory burst frequency 4
- Hypoglycemic episodes are infrequent with gliclazide MR (approximately 5% of patients) 1
- No episodes of nocturnal hypoglycemia or hypoglycemia requiring third-party assistance were observed in clinical trials of gliclazide MR 1
Dose Optimization
- Dose escalation from 40 mg to 80 mg daily has been associated with significant improvement in mean blood glucose 5
- Further escalation from 80 mg to 160 mg daily may not provide additional clinical benefit in most patients 5
- Even low doses (20 mg daily) have shown efficacy in patients with relatively good glycemic control (HbA1c <7.0%) 6
Monitoring Recommendations
- Monitor fasting and postprandial glucose levels to assess efficacy 1, 4
- Adjust dose based on glycemic response, with the goal of achieving target HbA1c 1
- Watch for symptoms of hypoglycemia, especially when initiating therapy or increasing doses 6
- Consider reducing the dose if HbA1c is well-controlled or if there are frequent episodes of hypoglycemia 3