Insulin Glargine (Lantus) Dose Adjustment with Diamicron MR 120mg
When increasing Lantus (insulin glargine) dose in combination with Diamicron MR (gliclazide) 120mg, start with a 10% increase in the Lantus dose and adjust every 3 days based on fasting blood glucose levels, while monitoring closely for hypoglycemia due to the additive effects of both medications.
Initial Dose Adjustment Strategy
When adjusting Lantus dose in combination with Diamicron MR 120mg:
Starting point for dose increases:
- Begin with a 10% increase in current Lantus dose
- Adjust every 3 days until target fasting glucose of 80-130 mg/dL is achieved 1
Monitoring requirements:
- Check fasting blood glucose daily
- Monitor more frequently in the first 3-4 weeks after dose changes
- Be vigilant for signs of hypoglycemia, especially at night
Special Considerations with Sulfonylureas
Diamicron MR (gliclazide) is a sulfonylurea that increases insulin secretion, creating important considerations when combined with Lantus:
- Hypoglycemia risk: The combination increases hypoglycemia risk due to additive effects 2
- Dose adjustment: Consider reducing Diamicron MR dose by 50% when increasing Lantus significantly 2
- Mechanism: Gliclazide increases both insulin pulse mass and basal insulin secretion 3, which can potentiate the effect of exogenous insulin
Kidney Function Considerations
- eGFR assessment: Monitor kidney function as it affects both medications
- Dose reduction: For patients with eGFR <60 mL/min/1.73m², consider a lower starting dose of Lantus (0.114 U/kg/day) 4
- Monitoring frequency: Increase monitoring frequency to every 3-6 months if eGFR <60 mL/min/1.73m² 2
Practical Titration Algorithm
For patients on both Lantus and Diamicron MR 120mg:
| Fasting Blood Glucose | Lantus Dose Adjustment |
|---|---|
| >180 mg/dL | Increase by 4 units |
| 140-180 mg/dL | Increase by 2 units |
| 110-139 mg/dL | Increase by 1 unit |
| 80-110 mg/dL | No change |
| <80 mg/dL | Decrease by 2 units |
Timing and Administration
- Lantus administration: Administer at the same time each day for consistent effect 1
- Split dosing option: Consider twice-daily Lantus if experiencing significant morning hypoglycemia despite dose titration 5
- Do not mix: Insulin glargine should not be mixed with other forms of insulin due to its acidic pH 2
Monitoring for Adverse Effects
- Hypoglycemia signs: Educate patient on recognizing hypoglycemia (sweating, tremors, confusion)
- Nocturnal hypoglycemia: Monitor especially carefully as this is a common risk with long-acting insulin and sulfonylureas
- Carry glucose source: Patient should always have quick-acting carbohydrates available 1
Dose Calculation Formula
For patients requiring significant dose adjustments, consider this formula:
Optimal daily Lantus dose = starting dose (0.15 × weight in kg) + incremental dose (baseline HbA1c - target HbA1c + 2) 4
- Reduce starting factor to 0.135 for women
- Reduce starting factor to 0.132 for patients on sulfonylureas like Diamicron MR
Cautions
- Avoid large (>20%) initial reductions in insulin dose when making adjustments 2
- Be aware that patients with decreased kidney function have increased risk of hypoglycemia due to decreased insulin clearance 2
- Monitor for potency issues with insulin - if unexplained increases in blood glucose occur, consider replacing the vial 2
Following this structured approach will help optimize glycemic control while minimizing the risk of hypoglycemia when adjusting Lantus doses in patients also taking Diamicron MR 120mg.