In a patient taking prednisone each morning, who currently receives 52 U neutral protamine Hagedorn (NPH) insulin and 20 U rapid‑acting insulin in the morning and 8 U NPH insulin in the evening, with evening blood glucose in the low‑100 mg/dL range, how should the NPH insulin be redistributed to achieve more even basal coverage?

Redistribute NPH to Prevent Evening Hypoglycemia in Steroid-Induced Hyperglycemia

Reduce your evening NPH from 8 units to 0 units and increase your morning NPH from 52 units to approximately 60 units as a single morning dose, administered concurrently with your 8 AM prednisone. 1

Rationale for Single Morning NPH Dosing

• Morning-only NPH is specifically designed for steroid-induced hyperglycemia because the 4–6 hour peak of NPH aligns with the midday-to-midnight hyperglycemic effect of morning prednisone. 1
• Your current evening NPH dose of 8 units is causing nocturnal hypoglycemia (blood glucose 93–104 mg/dL) because prednisone's hyperglycemic effect wanes overnight, leaving excess insulin action during sleep. 1
• The standard 2/3 morning and 1/3 evening split-dose regimen is appropriate for routine diabetes management, not for steroid-induced hyperglycemia where glucose elevation is time-restricted to daytime hours. 2

Specific Dose Adjustment Protocol

• Eliminate the evening 8 units of NPH entirely to prevent further nocturnal hypoglycemia. 1
• Increase morning NPH to 60 units (approximately 15% increase from your current 52 units) to maintain adequate daytime coverage while accounting for the removal of evening basal insulin. 1
• Administer the full morning NPH dose at the same time as your 8 AM prednisone to synchronize insulin peak with steroid-induced hyperglycemia. 1

Monitoring and Further Titration

• Check blood glucose every 2–4 hours for the first 48 hours after making this change to identify patterns of hyper- or hypoglycemia. 1
• Target fasting glucose < 130 mg/dL and daytime glucose 140–180 mg/dL. 1
• If fasting glucose remains elevated above 130 mg/dL after 3 days, increase morning NPH by 2 units every 3 days until target is achieved. 1
• If any glucose reading falls < 70 mg/dL, immediately reduce the morning NPH dose by 10–20% (6–12 units) without waiting. 1

Why Not Split NPH for Steroid Therapy

• Do not use the standard 2/3:1/3 split-dose regimen in steroid-induced hyperglycemia; this approach is designed for patients with endogenous insulin deficiency, not pharmacologically-induced daytime hyperglycemia. 2
• Splitting NPH into twice-daily dosing is only indicated when A1C remains above goal despite optimized once-daily NPH or when adding prandial insulin coverage is needed—neither applies to your situation of isolated nocturnal hypoglycemia. 2
• Research confirms that NPH and glargine are equally effective for steroid-induced hyperglycemia, but NPH requires lower total daily doses (0.27 vs 0.34 units/kg) when used as a single morning injection. 3

Managing Your Short-Acting Insulin

• Continue your 20 units of short-acting insulin in the morning to cover breakfast and provide additional daytime correction. 1
• Consider tightening your carbohydrate-to-insulin ratio or adding correctional doses every 4 hours if daytime glucose exceeds 150 mg/dL despite the increased morning NPH. 1

Common Pitfall to Avoid

• Do not maintain evening NPH "just in case"—the continuous tube feeding does not require evening basal insulin when prednisone is dosed only in the morning, and doing so perpetuates nocturnal hypoglycemia. 1
• If you later taper or discontinue prednisone, reduce morning NPH by 20–30% immediately to prevent severe hypoglycemia as steroid-induced insulin resistance resolves. 1