How to adjust Lantus (insulin glargine) dosage?

How to Adjust Lantus (Insulin Glargine) Dosage

Start Lantus at 10 units per day or 0.1-0.2 units/kg per day, then increase by 2 units every 3 days until fasting plasma glucose reaches target (80-130 mg/dL) without hypoglycemia. 1

Initial Dosing

• Begin with 10 units once daily OR 0.1-0.2 units/kg per day 1
• For patients with severe hyperglycemia (A1C >10% or glucose ≥300 mg/dL), consider starting at 0.3-0.4 units/kg per day 1
• Administer at the same time each day—timing can be morning, evening, or bedtime based on patient schedule and glucose patterns 1, 2

Titration Algorithm

The evidence-based approach is straightforward: 1

• Increase dose by 2 units every 3 days if fasting glucose remains above target 1
• Target fasting plasma glucose: 80-130 mg/dL (4.4-7.2 mmol/L) 1
• Base adjustments on the mean fasting glucose over the previous 3 days 3

Alternative patient-managed titration (shown to achieve better A1C reduction): 3

• Increase by 2 units every 3 days in the absence of hypoglycemia (glucose <72 mg/dL) 3
• This approach resulted in greater A1C reductions (-1.22% vs -1.08%) compared to clinic-managed titration 3

Managing Hypoglycemia

• If hypoglycemia occurs (glucose <80 mg/dL or <4.4 mmol/L): 1
  • Determine the cause first 1
  • If no clear reason identified, reduce dose by 10-20% 1
  • If >2 fasting values per week are <80 mg/dL, decrease dose by 2 units 1

When to Reassess and Intensify

Monitor at every visit for signs of inadequate basal insulin coverage: 1

• Large bedtime-to-morning glucose differentials 1
• Significant postprandial glucose excursions (>180 mg/dL) 1
• High glucose variability or persistent A1C above goal 1
• Daily dose exceeding 0.5 units/kg, especially approaching 1 unit/kg 1

If A1C remains above goal after 3-6 months of optimized basal insulin: 1

• Consider adding GLP-1 receptor agonist (may use fixed-ratio combination like iGlarLixi) 1
• Consider adding prandial insulin if significant postprandial excursions persist 1

Special Populations

Older adults (≥65 years): 1

• Use more conservative fasting glucose targets: 90-150 mg/dL (5.0-8.3 mmol/L) 1
• Consider morning dosing to reduce nocturnal hypoglycemia risk 1
• If dose titration shows 50% of fasting values above goal over 2 weeks, increase by 2 units 1

Steroid-induced hyperglycemia: 4

• Start at 0.3 units/kg per day (higher than standard dosing) 4
• Administer in the morning to match glucocorticoid pharmacokinetics 4
• Patients may require 40-60% more insulin than standard dosing 4
• Avoid bedtime NPH in this setting, but Lantus can be used morning or evening 4

Common Pitfalls to Avoid

• Do not undertitrate: Many patients remain on inadequate doses for months, leading to prolonged hyperglycemia and worse outcomes 1
• Do not delay adjustments: Titrate every 3 days, not weekly or monthly 1
• Do not ignore nocturnal hypoglycemia: Lantus has lower nocturnal hypoglycemia risk than NPH, but switching timing (bedtime to morning or vice versa) may help if it occurs 5, 2
• Do not mix with other insulins in the same syringe: Lantus may coprecipitate with rapid-acting insulins 2
• Do not continue aggressive basal titration indefinitely: Once daily dose exceeds 0.5-1.0 units/kg without reaching goal, consider adding prandial coverage rather than further increasing basal dose 1

Monitoring Requirements

• During titration phase: Daily fasting glucose monitoring is essential 1, 6
• After stabilization: Frequency can be reduced based on individual needs 1
• Assess adequacy at every clinical visit using fasting glucose trends and A1C 1