What is the initial dosing for NPH (Neutral Protamine Hagedorn) insulin?

NPH Insulin Dosing

Start NPH insulin at 10 units daily or 0.1-0.2 units/kg/day, administered as a single morning dose for most patients with type 2 diabetes, or split into twice-daily dosing (two-thirds morning, one-third evening) for patients requiring more comprehensive coverage. 1

Initial Dosing Strategy

Standard Starting Dose

• Begin with 10 units subcutaneously once daily OR 0.1-0.2 units/kg/day 1
• For a 70 kg patient, this translates to approximately 7-14 units daily 2
• Administer as bedtime NPH when used as basal insulin replacement 1
• Administer as morning NPH specifically for steroid-induced hyperglycemia to match glucocorticoid peak effect 2, 3

Timing Considerations

• Bedtime administration is the standard approach for basal insulin coverage in type 2 diabetes 1
• Morning administration is specifically indicated for steroid-induced hyperglycemia, as NPH peaks at 4-6 hours, aligning with glucocorticoid-induced hyperglycemia 2, 3
• For twice-daily regimens, give two-thirds of total dose before breakfast and one-third before dinner 1

Titration Protocol

Dose Adjustment Algorithm

• Increase by 2 units every 3 days to reach fasting plasma glucose target without hypoglycemia 1
• Set an individualized fasting glucose target (typically 80-130 mg/dL) 1
• If hypoglycemia occurs, reduce dose by 10-20% after determining no clear precipitating cause 1, 2
• Continue titration until fasting glucose consistently meets target 1

Monitoring Requirements

• Check fasting glucose daily during titration phase 1
• For hospitalized patients or those on enteral/parenteral nutrition, monitor every 2-4 hours 1, 2
• Target blood glucose range of 80-180 mg/dL in hospital settings 2

Special Populations and Situations

Enteral/Parenteral Nutrition

• Start with 5 units NPH subcutaneously every 12 hours or 10 units every 24 hours if no prior insulin history 1
• Calculate nutritional insulin component as 1 unit per 10-15 grams of carbohydrate per day 1
• This typically represents 50-70% of total daily insulin dose when patient is receiving continuous feeding 1
• Add correctional insulin every 4-6 hours using rapid-acting or regular insulin 1

Steroid-Induced Hyperglycemia

• Initial dose: 0.1-0.2 units/kg/day administered in the morning 2, 3
• For high-dose glucocorticoids, expect 40-60% higher insulin requirements than standard dosing 2, 3
• Administer NPH in morning to coincide with peak steroid effect (4-6 hours post-dose) 2, 3
• When tapering steroids, reduce NPH dose by 10-20% to prevent hypoglycemia 2, 4

Conversion from Bedtime to Twice-Daily NPH

• Use 80% of current bedtime NPH dose as the new total daily dose 1, 2
• Distribute as two-thirds morning and one-third evening 1
• This conversion is appropriate when once-daily dosing provides inadequate daytime coverage 1

Common Pitfalls to Avoid

Dosing Errors

• Do not rely solely on fasting glucose to guide NPH dosing in steroid-induced hyperglycemia, as this leads to under-treatment of daytime hyperglycemia and potential nocturnal hypoglycemia 3
• Avoid increasing basal insulin beyond approximately 0.5 units/kg/day without considering overbasalization and need for prandial insulin 1
• Do not discontinue basal insulin in type 1 diabetes patients even if enteral feedings are stopped, as this risks diabetic ketoacidosis 1

Hypoglycemia Management

• When hypoglycemia occurs, systematically evaluate for precipitating causes (missed meals, increased activity, medication errors) 1
• If no clear cause identified, reduce dose by 10-20% before next administration 1, 2
• In hospitalized patients with documented hypoglycemia, 75% have no insulin dose adjustment made—this represents a critical safety gap that must be addressed 1

Transition Considerations

• Insulin requirements decrease rapidly after steroid discontinuation—prompt dose adjustments are essential to avoid hypoglycemia 2
• For patients on tube feedings, NPH must be reduced or held if feeding is interrupted, as NPH duration of action is 12-18 hours 4
• Consider switching to long-acting basal analogs if patient develops recurrent hypoglycemia or frequently forgets evening NPH doses 1

Comparison with Long-Acting Analogs

• NPH requires more frequent dosing (1.6-1.9 injections daily) compared to glargine (1.1 injections daily) 5
• Long-acting analogs (glargine, detemir) reduce symptomatic and nocturnal hypoglycemia risk compared to NPH, though advantages are modest 1
• NPH remains the preferred choice for steroid-induced hyperglycemia due to its intermediate-acting profile matching glucocorticoid pharmacokinetics 2, 3
• Cost considerations may favor NPH in resource-limited settings 1