How should Novolin (human insulin) be administered to a patient with diabetes?

Novolin Administration Guidelines

Novolin (human insulin) should be administered subcutaneously 30-45 minutes before meals when used as prandial insulin, or according to specific timing protocols based on the formulation type (NPH, Regular, or premixed). 1

Route of Administration

Subcutaneous injection is the standard route for Novolin administration in non-critical care settings. 1 For critically ill patients requiring intensive glucose control, intravenous insulin infusion is the most effective method, but this applies to continuous infusion protocols rather than standard Novolin administration. 1

Timing Based on Formulation Type

Novolin R (Regular Human Insulin)

• Administer 30-45 minutes before meals to allow adequate absorption time for optimal postprandial glucose control 1
• For patients receiving enteral bolus feedings, give approximately 1 unit per 10-15 g carbohydrate subcutaneously before each feeding 1
• Regular human insulin may be added directly to parenteral nutrition solutions for patients receiving continuous peripheral or central nutrition 1

Novolin N (NPH Insulin)

• For steroid-induced hyperglycemia, administer NPH in the morning to match the pharmacokinetic profile of daily glucocorticoid therapy 2
• For basal coverage without steroid use, NPH can be given every 12 hours (typically morning and bedtime) 1
• A reasonable starting point for insulin-naive patients is 5 units of NPH subcutaneously every 12 hours 1

Novolin 70/30 (Premixed Insulin)

• Administer twice daily before breakfast and dinner 1
• Important caveat: Premixed insulin formulations are NOT routinely recommended for in-hospital use due to significantly increased hypoglycemia rates compared to basal-bolus regimens 1

Injection Site and Technique

• Rotate injection sites systematically to prevent lipohypertrophy and ensure consistent absorption 1
• Common sites include abdomen, thighs, upper arms, and buttocks
• Absorption is fastest from the abdomen, followed by arms, thighs, and buttocks

Critical Timing Considerations

For Hyperglycemic Patients

When pre-meal glucose is elevated (>180 mg/dL), administering regular insulin 15-30 minutes before the meal significantly improves postprandial glucose excursion compared to injection at mealtime. 3 The postprandial glucose excursion was reduced by -5.1 to -6.4 mmol/L/hour when insulin was given 15-30 minutes pre-meal versus +3.4 to +5.7 mmol/L/hour when given at or after the meal. 3

For Well-Controlled Patients

In patients with type 1 diabetes who are well-controlled on basal-bolus therapy, injecting regular insulin 5 minutes versus 30 minutes before meals showed minimal differences in overall glucose control, though a trend toward greater 90-minute postprandial increases was observed with the 5-minute timing. 4

Dosing Alignment with Meals

For patients eating regular meals, insulin injections must align with meals, and point-of-care glucose testing should be performed immediately before meals. 1

Critical safety measure: If oral intake is poor or unpredictable, administer prandial insulin immediately AFTER the patient eats, with the dose adjusted for the amount actually ingested. 1 This prevents severe hypoglycemia in patients who may not complete their meal.

Special Administration Protocols

Continuous Tube Feedings

For patients receiving continuous enteral nutrition, the total daily nutritional insulin component should be calculated as 1 unit per 10-15 g carbohydrate per day, or as 50-70% of the total daily insulin dose. 1

Correctional (Sliding Scale) Insulin

Correctional insulin should be administered subcutaneously every 6 hours using human regular insulin or every 4 hours using rapid-acting insulin. 1 However, sliding scale insulin as monotherapy is strongly discouraged and should never be the sole treatment approach. 1

Transition from IV to Subcutaneous

When discontinuing intravenous insulin, administer subcutaneous basal insulin 2-4 hours BEFORE stopping the IV infusion to prevent rebound hyperglycemia. 1 Converting to basal insulin at 60-80% of the 24-hour IV infusion dose is an effective approach. 1

Common Pitfalls to Avoid

• Never administer rapid-acting or regular insulin at bedtime for correction purposes, as this significantly increases nocturnal hypoglycemia risk 1
• Never mix Novolin with other insulin formulations in the same syringe unless specifically indicated (e.g., NPH can be mixed with regular insulin) 1
• Never rely solely on sliding scale insulin without scheduled basal and prandial components, as this leads to dangerous glucose fluctuations 1
• Never delay insulin administration beyond the recommended pre-meal window, as this results in inadequate postprandial glucose control 3