What adjustments should be made to the Lantus (insulin glargine) dose for a patient with hyperglycemia after missing carbohydrate coverage?

Lantus Dose Adjustment for Fasting Hyperglycemia

Increase your Lantus dose by 4 units (from 30 to 34 units) immediately, and continue increasing by 4 units every 3 days until your fasting blood glucose reaches 80-130 mg/dL. 1

Understanding Your Current Situation

Your fasting blood glucose of 187 mg/dL indicates inadequate basal insulin coverage, regardless of whether you missed carbohydrate coverage. 2 The missed meal insulin (carb coverage) affects postprandial glucose, not fasting levels—your elevated fasting glucose reflects insufficient overnight basal insulin action. 1

Evidence-Based Titration Protocol

For fasting glucose ≥180 mg/dL, the American Diabetes Association recommends increasing basal insulin by 4 units every 3 days until reaching target fasting glucose of 80-130 mg/dL. 1, 2

• If your fasting glucose drops to 140-179 mg/dL after adjustment, reduce the increment to 2 units every 3 days 1
• Continue daily fasting blood glucose monitoring during this titration phase 1, 2
• If any hypoglycemia occurs (glucose <70 mg/dL), immediately reduce your dose by 10-20% (3-6 units from current dose) 1

Critical Threshold Awareness

Monitor your total daily Lantus dose carefully—when it exceeds 0.5 units/kg/day (approximately 35-40 units for a 70-80 kg person), you may need prandial insulin added rather than continuing to escalate basal insulin alone. 1

Clinical signs that you're approaching this threshold include: 1

• Basal insulin dose >0.5 units/kg/day
• Large difference between bedtime and morning glucose (≥50 mg/dL)
• Experiencing hypoglycemia episodes
• High glucose variability throughout the day

Foundation Therapy Verification

Ensure you're on metformin (unless contraindicated), as it should be continued when intensifying insulin therapy and helps reduce total insulin requirements. 1

Common Pitfalls to Avoid

• Don't wait longer than 3 days between dose adjustments in stable situations—this unnecessarily prolongs time to achieve glycemic targets 1
• Don't blame the missed carb coverage for fasting hyperglycemia—fasting glucose reflects basal insulin adequacy, not meal coverage 3
• Don't continue escalating Lantus indefinitely—if your dose approaches 0.5-1.0 units/kg/day without achieving targets, adding prandial insulin becomes more appropriate 1

Monitoring Requirements

• Check fasting blood glucose daily during titration 1, 2
• Reassess your insulin regimen every 3-6 months once stable 1
• If fasting glucose normalizes but HbA1c remains elevated, this signals need for mealtime insulin coverage rather than more basal insulin 2