How to manage a patient with hyperglycemia on 30 units of glargine (insulin glargine) with a fasting blood sugar of 380 mg/dL?

Immediate Insulin Dose Adjustment Required

For a fasting blood sugar of 380 mg/dL on 30 units of glargine, increase the dose by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL, and strongly consider adding prandial insulin coverage immediately given the severity of hyperglycemia. 1, 2

Aggressive Basal Insulin Titration

• Increase glargine by 4 units every 3 days when fasting glucose is ≥180 mg/dL until reaching target of 80-130 mg/dL 1, 2
• For this patient with fasting glucose of 380 mg/dL, the current 30 units is clearly insufficient and requires immediate escalation 2
• Continue daily fasting blood glucose monitoring during titration to guide adjustments 1, 2

Critical Threshold Monitoring

• Watch for overbasalization when basal insulin exceeds 0.5 units/kg/day (approximately 35-40 units for most adults) 1, 2
• Clinical signals of overbasalization include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia episodes, and high glucose variability 1, 2
• When basal insulin approaches 0.5-1.0 units/kg/day without achieving glycemic targets, adding prandial insulin becomes more appropriate than continuing to escalate basal insulin alone 1, 2

Adding Prandial Insulin Coverage

• Given the severity of hyperglycemia (fasting 380 mg/dL), strongly consider initiating prandial insulin immediately rather than waiting for basal optimization alone 1, 2
• Start with 4 units of rapid-acting insulin before the largest meal, or use 10% of the current basal dose (approximately 3-4 units) 1, 2
• Titrate prandial insulin by 1-2 units or 10-15% every 3 days based on 2-hour postprandial glucose readings 1, 2

Foundation Therapy Optimization

• Verify the patient is on metformin (up to 2000-2550 mg daily) unless contraindicated, as this combination provides superior glycemic control with reduced insulin requirements 1, 2
• Continue metformin when intensifying insulin therapy—do not discontinue 1, 2
• Discontinue sulfonylureas if present when advancing beyond basal-only insulin to prevent hypoglycemia 1, 2

Expected Outcomes and Timeline

• With aggressive titration (4 units every 3 days), most patients reach fasting glucose targets within 2-4 weeks 2, 3
• Fasting glucose of 380 mg/dL likely reflects both inadequate basal coverage AND postprandial excursions requiring mealtime insulin 2
• The principal action of basal insulin is to restrain hepatic glucose production overnight and between meals 1, 4, 5

Common Pitfalls to Avoid

• Do not delay insulin intensification—prolonged severe hyperglycemia increases complication risk 1, 2, 4
• Do not continue escalating basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia, as this leads to overbasalization with increased hypoglycemia risk and suboptimal control 1, 2
• Do not rely solely on correction (sliding scale) insulin—scheduled basal-bolus therapy is superior 1, 2, 6
• If hypoglycemia occurs without clear cause, reduce the dose by 10-20% immediately 1, 2

Patient Education Essentials

• Teach recognition and treatment of hypoglycemia with 15 grams of fast-acting carbohydrate 1, 2
• Ensure proper insulin injection technique and site rotation to prevent lipohypertrophy 1, 6
• Provide written instructions for self-titration based on fasting glucose patterns 2, 3