Can a patient with uncontrolled morning hyperglycemia (200-300 mg/dL) on Novolin 70/30 (aspart protamine/aspart) 10 units daily be switched to Lantus (insulin glargine)?

Switching from Novolin 70/30 to Lantus for Uncontrolled Morning Hyperglycemia

Yes, you should switch from Novolin 70/30 to Lantus (insulin glargine), but the current 10 units daily dose is grossly inadequate for morning sugars of 200-300 mg/dL—you need to start Lantus at a higher dose and titrate aggressively. 1

Why the Current Regimen is Failing

• Novolin 70/30 is a premixed insulin (70% NPH/30% regular insulin) that provides both basal and prandial coverage, but 10 units once daily is insufficient for any meaningful glycemic control when morning sugars are 200-300 mg/dL. 2, 3
• The American Diabetes Association recommends starting basal insulin at 10 units once daily OR 0.1-0.2 units/kg body weight for insulin-naive patients with type 2 diabetes, but this patient clearly needs more aggressive dosing given the severe hyperglycemia. 1
• Morning fasting glucose of 200-300 mg/dL indicates inadequate basal insulin coverage overnight, which is the primary role of Lantus. 1

Recommended Switching Strategy

Immediate Action: Switch to Lantus with Aggressive Dosing

• Start Lantus at 0.2 units/kg body weight once daily (or at minimum 10-15 units if weight unknown), administered at the same time each day, preferably at bedtime to target morning fasting glucose. 1, 4
• For fasting glucose ≥180 mg/dL, increase Lantus by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL. 1
• If fasting glucose is 140-179 mg/dL, increase by 2 units every 3 days. 1

Critical Threshold to Monitor

• When Lantus dose exceeds 0.5 units/kg/day without achieving glycemic targets, you must add prandial insulin rather than continuing to escalate basal insulin alone—this prevents "overbasalization" which causes hypoglycemia without improved control. 1
• Clinical signs 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

Essential Concurrent Therapy

• Continue or start metformin at maximum tolerated dose (up to 2000-2500 mg daily) unless contraindicated, as this combination provides superior glycemic control with reduced insulin requirements and less weight gain compared to insulin alone. 1, 5
• The American Diabetes Association explicitly recommends continuing metformin when adding or intensifying insulin therapy. 1

Daily Monitoring Requirements

• Check fasting blood glucose every morning during titration and record all values to guide dose adjustments every 3 days. 1
• Target fasting glucose: 80-130 mg/dL. 1
• If hypoglycemia occurs without clear cause, reduce Lantus dose by 10-20% immediately. 1

When to Add Prandial Insulin

• If after 3-6 months of optimizing Lantus, fasting glucose reaches target but HbA1c remains above goal, or if Lantus dose approaches 0.5-1.0 units/kg/day without achieving HbA1c targets, add prandial insulin. 1
• Start with 4 units of rapid-acting insulin before the largest meal, or use 10% of the current basal dose. 1
• Titrate prandial insulin by 1-2 units or 10-15% every 3 days based on 2-hour postprandial glucose readings. 1

Critical Pitfalls to Avoid

• Do not continue with only 10 units of any insulin when morning sugars are 200-300 mg/dL—this represents dangerous therapeutic inertia that prolongs hyperglycemia exposure and increases complication risk. 1, 5
• Do not rely on sliding scale insulin alone—the American Diabetes Association explicitly condemns this approach as it treats hyperglycemia reactively rather than preventing it. 1, 6
• Do not delay insulin intensification—prolonged severe hyperglycemia (months at glucose levels >200 mg/dL) should be specifically avoided due to increased risk of complications. 1, 5

Administration Guidelines

• Administer Lantus subcutaneously into the abdominal area, thigh, or deltoid, rotating injection sites within the same region to reduce risk of lipodystrophy. 4
• Do not dilute or mix Lantus with any other insulin or solution due to its low pH. 1, 4
• Lantus should be administered at the same time every day for consistent basal coverage. 1, 4