How do you calculate the Lantus (insulin glargine) dose?

Lantus (Insulin Glargine) Dosing Calculation

The optimal starting dose for Lantus (insulin glargine) is 0.1-0.2 units/kg/day or 10 units per day, with subsequent titration of 2 units every 3 days until the fasting plasma glucose target is reached without hypoglycemia. 1

Initial Dosing Recommendations

Starting Dose Options:

• Weight-based approach: 0.1-0.2 units/kg/day 1
• Fixed dose approach: 10 units per day 1

Special Population Considerations:

• Patients with retinopathy: Consider lower starting dose of 0.12 units/kg/day 2
• Patients with renal impairment (eGFR <60 mL/min/1.73m²): Consider lower starting dose of 0.114 units/kg/day 2
• Women: May require slightly lower starting dose (0.135 units/kg/day) 2
• Patients on sulfonylureas: Consider slightly lower starting dose (0.132 units/kg/day) 2

Dose Titration Algorithm

1. Set a fasting plasma glucose target based on individual patient factors 1
2. Increase dose by 2 units every 3 days until target fasting glucose is reached without hypoglycemia 1
3. If hypoglycemia occurs: Determine cause; if no clear reason, reduce dose by 10-20% 1

Practical Formula for Dose Calculation

A simplified formula derived from clinical data can be used for dose calculation 2:

Optimal daily dose = Starting dose (0.15 × weight in kg) + Incremental dose (baseline HbA1c - target HbA1c + 2)

Administration Considerations

• Administer once daily at the same time each day 3, 4
• Can be administered at any time of day, though evening dosing is most common 4
• In patients with highly variable insulin requirements or high insulin resistance, twice-daily dosing may be considered 4

Monitoring and Dose Assessment

• Assess adequacy of insulin dose at every visit 1
• Monitor for signs of overbasalization (elevated bedtime-to-morning glucose differential, hypoglycemia, high glucose variability) 1
• If A1C remains above goal despite optimized basal insulin, consider adding prandial insulin or GLP-1 receptor agonist 1

Common Pitfalls to Avoid

1. Underdosing: Starting with too low a dose can delay achievement of glycemic targets
2. Overly aggressive titration: Can increase risk of hypoglycemia
3. Failure to adjust for special populations: Patients with renal impairment or retinopathy may require lower doses 2
4. Mixing with other insulins: Lantus should not be mixed with other insulins in the same syringe 4
5. Inadequate monitoring: Failure to regularly assess fasting glucose levels can lead to suboptimal dosing

By following this structured approach to Lantus dosing, you can optimize glycemic control while minimizing the risk of hypoglycemia in patients requiring basal insulin therapy.