What is the recommended weight-based dosing of NPH (Neutral Protamine Hagedorn) insulin for managing steroid-induced hyperglycemia?

Weight-Based Dosing of NPH Insulin for Steroid-Induced Hyperglycemia

For steroid-induced hyperglycemia, the recommended initial NPH insulin dosing is 0.3-0.5 units/kg per day administered in the morning to match the pharmacokinetic profile of daily glucocorticoid therapy. 1

Initial Dosing Recommendations

• Start with 0.1-0.2 units/kg per day for patients with mild hyperglycemia or those who are insulin-naïve 1
• Use 0.3-0.5 units/kg per day for patients on high-dose glucocorticoids or with significant insulin resistance 1, 2
• For patients with higher BMI, consider using the higher end of the dosing range due to increased insulin resistance 2
• When converting from bedtime NPH to morning NPH for steroid coverage, use 80% of the current bedtime NPH dose to reduce hypoglycemia risk 3, 4

Administration Timing

• Administer NPH insulin in the morning to coincide with the peak action of daily glucocorticoids 3, 1
• This timing alignment helps address the predominant hyperglycemia pattern seen with steroids (midday to midnight) 5
• Morning administration allows for better monitoring during waking hours and reduces risk of undetected nocturnal hypoglycemia 4

Dose Titration and Monitoring

• Monitor blood glucose every 2-4 hours initially, particularly before meals and at bedtime 1, 2
• For persistent hyperglycemia, increase the dose by 2 units every 3 days until target blood glucose is achieved 1
• If hypoglycemia occurs, determine the cause; if no clear reason is found, lower the NPH dose by 10-20% 3, 1
• Assess adequacy of insulin dose at every visit and consider clinical signals of overbasalization 3

Adjusting for Steroid Taper

• Reduce NPH insulin dose by 10-20% when tapering steroids to prevent hypoglycemia 1
• For patients on twice-daily NPH regimen, focus primarily on reducing the morning dose when tapering morning steroids 1
• Continue monitoring closely during steroid taper as insulin requirements will decrease proportionally 1

Special Considerations

• Patients with renal impairment may require lower initial doses (0.1-0.2 units/kg) due to decreased insulin clearance 4
• For patients with significant insulin resistance or on high-dose steroids, insulin requirements may be 40-60% higher than standard dosing 1, 2
• Consider splitting the NPH dose (2/3 morning, 1/3 evening) if daytime hyperglycemia persists despite dose adjustments 1

Alternative Approaches

• If glycemic targets are not achieved with once-daily morning NPH, consider converting to a twice-daily NPH regimen 3, 4
• For patients struggling with multiple daily injections, mixed insulin formulations containing NPH may be considered 3
• Consider adding prandial insulin if postprandial hyperglycemia persists despite NPH optimization 3

Common Pitfalls to Avoid

• Avoid bedtime NPH in patients with steroid-induced hyperglycemia as the peak action may cause nocturnal hypoglycemia 2
• Do not underestimate insulin requirements in patients on high-dose steroids; inadequate dosing leads to persistent hyperglycemia 2, 6
• Be aware that more aggressive initial NPH dosing based on steroid dose (approximately 0.5 units/mg prednisone equivalent) may allow for earlier achievement of euglycemia without increased hypoglycemia risk 6