How should therapy be adjusted for a patient with uncontrolled diabetes, on a sliding scale regimen with Humalog (insulin lispro) and 30 units of Lantus (insulin glargine) at bedtime, with a hemoglobin A1c (HbA1c) level of 10.7%?

Adjusting Insulin Therapy for Uncontrolled Diabetes with A1c of 10.7%

For a patient with an A1c of 10.7% on sliding scale Humalog and 30 units of Lantus at bedtime, therapy should be intensified to a basal-bolus insulin regimen with fixed mealtime insulin doses rather than sliding scale, and the Lantus dose should be increased by approximately 10-20% (to 33-36 units).

Assessment of Current Regimen

The current regimen is inadequate for several reasons:

• A1c of 10.7% indicates severely uncontrolled diabetes (target is <7% for most patients) 1
• Sliding scale insulin alone is reactive rather than proactive
• The basal insulin dose may be insufficient

Recommended Treatment Adjustments

1. Intensify Basal Insulin

• Increase Lantus (insulin glargine) from 30 units to 33-36 units (10-20% increase)
• Continue administering at bedtime
• Further titrate based on fasting blood glucose levels, aiming for target of <126 mg/dL 1

2. Convert from Sliding Scale to Fixed Mealtime Dosing

• Replace sliding scale Humalog with fixed pre-meal doses of rapid-acting insulin (Humalog)
• Start with approximately 0.1-0.2 units/kg per meal (typically 4-8 units per meal for average-sized adult)
• Adjust based on carbohydrate intake, pre-meal glucose, and anticipated activity 2

3. Implement Structured Monitoring

• Monitor blood glucose 4 times daily (before meals and at bedtime)
• Add post-prandial testing 1-2 hours after meals to guide prandial insulin adjustments 1
• Re-evaluate A1c in 3 months 2

Rationale for Recommendations

The American Diabetes Association recommends that patients with severely uncontrolled diabetes (A1c ≥10%) should be treated with insulin therapy 2, 1. For patients with type 1 diabetes, multiple daily injections (MDI) with basal and prandial insulin is the recommended approach 2, and similar principles apply to patients with type 2 diabetes with severe hyperglycemia.

Clinical studies have demonstrated that basal-bolus insulin regimens are more effective than basal insulin alone for patients with elevated A1c levels. In studies comparing insulin glargine with NPH insulin, both combined with insulin lispro, patients achieved better glycemic control with less hypoglycemia 3, 4.

Implementation Tips

• Educate the patient on carbohydrate counting to match prandial insulin to intake 2
• Start with conservative bolus doses to minimize hypoglycemia risk
• Consider using a consistent carbohydrate meal plan to simplify dosing
• Adjust the basal insulin dose every 3-4 days until fasting glucose targets are achieved

Common Pitfalls to Avoid

1. Inadequate basal insulin: Many providers hesitate to increase basal insulin sufficiently. Titrate based on fasting glucose values.

2. Overreliance on sliding scale: Sliding scale alone is reactive and leads to glucose fluctuations. Fixed mealtime doses with correction factors are more effective.

3. Insufficient monitoring: Without regular glucose monitoring, appropriate adjustments cannot be made.

4. Failure to address lifestyle factors: Reinforce consistent carbohydrate intake, physical activity, and medication adherence.

5. Delayed intensification: The high A1c of 10.7% indicates immediate need for regimen intensification rather than minor adjustments.

If the patient fails to achieve adequate control with the basal-bolus regimen after 3 months, consider adding a GLP-1 receptor agonist (for type 2 diabetes) or evaluating for insulin pump therapy (for type 1 diabetes) 1, 5.