Insulin Intensification Required for Rising A1c
This patient requires immediate insulin dose adjustment and discontinuation of glyburide, as the combination of a sulfonylurea with complex insulin regimens significantly increases hypoglycemia risk while providing inadequate glycemic control. 1
Critical Safety Issue: Discontinue Glyburide
- Glyburide is contraindicated in older adults and should be stopped immediately 1
- Glyburide is a longer-duration sulfonylurea associated with increased hypoglycemia risk, particularly problematic in elderly patients 1
- When moving beyond basal insulin to more complex regimens, sulfonylureas should be discontinued to prevent dangerous hypoglycemia 2
Current Regimen Analysis
The patient is on Novolin 70/30 (premixed insulin containing 70% NPH and 30% regular insulin):
- 22 units at breakfast
- 6 units at lunch
- 22 units at dinner
- Total daily dose: 50 units
This premixed regimen lacks the flexibility needed for proper titration, as the fixed 70:30 ratio cannot be individualized to match variable carbohydrate intake and activity patterns 2
Recommended Treatment Plan
Step 1: Simplify and Intensify the Insulin Regimen
Transition to basal-bolus therapy using the algorithm for older adults with type 2 diabetes 1:
- Calculate total daily dose (TDD): Current 50 units
- Split as 50% basal, 50% prandial 2, 3:
- Basal insulin (Lantus or similar): 25 units once daily at bedtime
- Prandial insulin (rapid-acting): Start with 8 units before each meal (25 units ÷ 3 meals)
Step 2: Titration Protocol
Basal insulin adjustment 2, 3:
- Increase by 4 units every 3 days if fasting glucose ≥180 mg/dL
- Increase by 2 units every 3 days if fasting glucose 140-179 mg/dL
- Target fasting glucose: 80-130 mg/dL
Prandial insulin adjustment 2:
- Increase by 1-2 units or 10-15% twice weekly based on 2-hour postprandial glucose readings
- Target postprandial glucose: <180 mg/dL
Step 3: Monitor for Overbasalization
Stop escalating basal insulin when dose exceeds 0.5 units/kg/day (approximately 35-40 units for most elderly patients) 2, 3
Warning signs of overbasalization include 2:
- Bedtime-to-morning glucose differential ≥50 mg/dL
- Hypoglycemia episodes
- High glucose variability
Alternative Simplified Approach for Elderly Patients
If the patient has difficulty with multiple daily injections or cognitive limitations 1:
Option: Twice-daily premixed insulin 2:
- Novolin 70/30: 25 units before breakfast, 25 units before dinner
- Simpler than basal-bolus but less flexible
- Titrate total daily dose upward by 10% weekly until A1c approaches target
Essential Monitoring
- Daily fasting blood glucose during titration phase 2, 3
- Check A1c every 3 months until stable 4
- Assess for hypoglycemia at every visit, particularly given advanced age 1
- If hypoglycemia occurs, reduce the corresponding insulin dose by 10-20% immediately 2, 3
Individualized A1c Target for Elderly Patients
Given the patient's age, target A1c of 7.5-8.0% may be more appropriate than <7.0% to minimize hypoglycemia risk while still preventing hyperglycemic symptoms 1, 4
Tight glycemic control (A1c <7%) in older adults with multiple medical conditions is considered overtreatment and should be avoided 1
Common Pitfalls to Avoid
- Do not continue glyburide when intensifying insulin—this dramatically increases hypoglycemia risk in elderly patients 1, 2
- Do not rely on sliding scale insulin alone—scheduled basal-bolus regimens are far superior 2
- Do not delay insulin intensification—the A1c rise from 9.3% to 10.3% indicates urgent need for adjustment 2, 4
- Do not continue escalating premixed insulin without addressing the lack of flexibility in the regimen 2