Insulin Dose Adjustments for Persistent Hyperglycemia
Your Lantus dose should be increased to 60 units (a 10-unit or 20% increase), your carb ratio should remain at 1:5 for now, and your correction factor should be changed from 1:25 to 1:20 to more aggressively address hyperglycemia. 1
Immediate Basal Insulin Adjustment
Your current situation shows inadequate basal insulin coverage with a fasting glucose of 231 mg/dL and post-meal glucose of 305 mg/dL despite carbohydrate correction. This indicates both insufficient basal coverage AND likely inadequate mealtime insulin.
Lantus Titration:
- Increase your Lantus by 10 units (from 50 to 60 units) immediately. 1 The American Diabetes Association recommends increasing basal insulin by 4 units every 3 days when fasting glucose is ≥180 mg/dL, but given your severely elevated levels (231 mg/dL), a more aggressive initial increase of 10 units (20%) is warranted. 1
- Continue increasing by 4 units every 3 days until your fasting glucose reaches 80-130 mg/dL. 1
- If fasting glucose remains 140-179 mg/dL after adjustments, increase by 2 units every 3 days. 1
Critical Threshold Warning
Watch for overbasalization: At 50 units, if you weigh approximately 50-100 kg, you're approaching or at the 0.5 units/kg/day threshold. 1 Once basal insulin exceeds 0.5 units/kg/day and approaches 1.0 units/kg/day, adding prandial insulin becomes more appropriate than continuing to escalate basal insulin alone. 1 Clinical signals of overbasalization include:
- Bedtime-to-morning glucose differential ≥50 mg/dL 1
- Hypoglycemia episodes 1
- High glucose variability 1
Carbohydrate Ratio Adjustment
Keep your carb ratio at 1:5 for now but monitor closely. 1 Your post-meal glucose of 305 mg/dL suggests either:
- Inadequate basal coverage (being addressed above)
- Insufficient mealtime insulin coverage
- Both
After optimizing basal insulin over the next 1-2 weeks, if post-meal glucose remains >180 mg/dL two hours after eating, then tighten your carb ratio to 1:4 (meaning 1 unit per 4 grams of carbohydrate). 1
Correction Factor (Sensitivity Factor) Adjustment
Change your correction factor from 1:25 to 1:20 immediately. 1 This means 1 unit of insulin will lower your blood glucose by approximately 20 mg/dL instead of 25 mg/dL, providing more aggressive correction of hyperglycemia.
The standard formula for correction factor is 1500/TDD (total daily dose). 1 If your total daily insulin dose is approximately 60-80 units, your correction factor should be around 1:19-25, so 1:20 is appropriate for more aggressive control.
Foundation Therapy Check
Ensure you're on metformin (unless contraindicated) at a dose of at least 1000mg twice daily (2000mg total). 1 Metformin should be continued when adding or intensifying insulin therapy, as it reduces total insulin requirements and provides complementary glucose-lowering effects. 1, 2
Monitoring Requirements
- Check fasting blood glucose daily during this titration phase. 1
- Monitor pre-meal and 2-hour post-meal glucose to assess adequacy of both basal and mealtime coverage. 1
- If you experience any hypoglycemia (glucose <70 mg/dL), reduce your insulin dose by 10-20% immediately. 1
When to Add Prandial Insulin
If after 2-3 weeks of optimizing basal insulin your fasting glucose reaches 80-130 mg/dL but your HbA1c remains elevated or post-meal glucose consistently exceeds 180 mg/dL, you'll need to add dedicated prandial (mealtime) insulin rather than relying solely on correction doses. 1
Start with 4 units of rapid-acting insulin before your largest meal (or 10% of your basal dose, approximately 5-6 units). 1 This provides scheduled mealtime coverage rather than reactive correction-only dosing, which is more effective for controlling postprandial hyperglycemia. 1
Common Pitfall to Avoid
Do not continue escalating Lantus beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia with dedicated prandial insulin. 1 Blood glucose in the 200-300 mg/dL range reflects both inadequate basal coverage AND postprandial excursions requiring mealtime insulin, not just correction doses. 1 Relying solely on correction insulin leads to suboptimal control and increased hypoglycemia risk. 1