What is the recommended dose of Insulatard (NPH insulin) for a patient with a blood glucose level of 309 mg/dL?

Immediate Insulin Dose Adjustment for Blood Glucose of 309 mg/dL

For a blood glucose of 309 mg/dL on Insulatard (NPH insulin), increase the dose by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL, and add correction insulin immediately using a sliding scale approach. 1

Understanding Your Current Situation

Your blood glucose of 309 mg/dL indicates inadequate basal insulin coverage and requires aggressive titration. 1 The target fasting glucose should be 80-130 mg/dL. 1

Immediate NPH Insulin Adjustment

• Increase your current NPH dose by 4 units every 3 days when fasting glucose is ≥180 mg/dL (which 309 mg/dL clearly exceeds). 1, 2
• Continue this aggressive titration until your fasting glucose consistently reaches 80-130 mg/dL. 1
• If you experience hypoglycemia (blood glucose <70 mg/dL) without clear cause, reduce the dose by 10-20% immediately. 1

Correction Insulin Protocol

For immediate management of your current hyperglycemia, implement this correction scale with regular insulin or rapid-acting insulin:

• Blood glucose 150-200 mg/dL: 2 units 3
• Blood glucose 201-250 mg/dL: 4 units 3
• Blood glucose 251-300 mg/dL: 6 units 3
• Blood glucose 301-350 mg/dL: 8 units 3
• Blood glucose >350 mg/dL: 10 units and notify provider 3

Based on your current glucose of 309 mg/dL, you would take 6 units of correction insulin now. 3

Critical Threshold Monitoring

• When your NPH dose exceeds 0.5 units/kg/day and approaches 1.0 units/kg/day without achieving glycemic targets, adding prandial (mealtime) insulin becomes more appropriate than continuing to escalate NPH alone. 1, 2
• Watch for signs of "overbasalization": bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia episodes, or high glucose variability throughout the day. 1

Daily Monitoring Requirements

• Check fasting blood glucose every morning during this titration phase. 1
• Record all glucose values to guide dose adjustments every 3 days. 1
• Monitor for hypoglycemia symptoms: shakiness, sweating, confusion, rapid heartbeat. 1

Foundation Therapy

• Continue metformin (if you're taking it) unless contraindicated, as this combination provides superior glycemic control with reduced insulin requirements. 2
• Metformin should be at maximum tolerated dose (up to 2000-2550 mg daily). 2

When to Add Mealtime Insulin

If after optimizing your NPH dose (achieving fasting glucose 80-130 mg/dL) your HbA1c remains above target after 3-6 months, you will need to add prandial insulin:

• Start with 4 units of rapid-acting insulin before the largest meal. 1
• Alternatively, use 10% of your current NPH dose as the starting prandial dose. 1
• Titrate prandial insulin by 1-2 units every 3 days based on 2-hour post-meal glucose readings. 1

Common Pitfalls to Avoid

• Do not wait longer than 3 days between NPH adjustments in stable conditions, as this unnecessarily prolongs time to achieve glycemic targets. 1
• Do not continue escalating NPH beyond 0.5-1.0 units/kg/day without addressing post-meal hyperglycemia, as this leads to overbasalization with increased hypoglycemia risk. 1, 2
• Never use correction insulin alone as your only treatment—you need scheduled basal insulin (NPH) as the foundation. 2

Hypoglycemia Management

• Treat any glucose <70 mg/dL immediately with 15 grams of fast-acting carbohydrate (3-4 glucose tablets, 4 oz juice, or 1 tablespoon honey). 1
• Recheck glucose in 15 minutes and repeat treatment if still <70 mg/dL. 1
• Always carry fast-acting carbohydrates with you. 1

When to Contact Your Healthcare Provider

• If fasting glucose remains >180 mg/dL after 2-3 weeks of titration. 1
• If you experience repeated hypoglycemia episodes. 1
• If your NPH dose exceeds 0.5 units/kg/day without achieving fasting glucose targets. 1