Insulin Therapy Guidelines

Introduction to Insulin Therapy

• The initial dose of insulin for patients requiring insulin therapy is typically 10 units per day or 0.1-0.2 units/kg per day, with subsequent titration by increasing 2 units every 3 days until reaching target fasting plasma glucose without hypoglycemia, as recommended by the American Diabetes Association 1, 2
• The American Diabetes Association recommends monitoring blood glucose regularly, especially when initiating or adjusting insulin doses to minimize the risk of hypoglycemia 1, 2
• The standard international unit (IU) is the universally accepted unit for insulin dosing, with insulin typically available in concentrations of 100 units per mL (U-100) as the most common formulation, according to the American Diabetes Association 3, 1

Initiation and Titration of Insulin Therapy

• For basal insulin, the initial dose is typically 10 units/day or 0.1-0.2 units/kg/day, as recommended by the American Diabetes Association 1
• Evidence-based titration involves increasing the dose by 2 units every 3 days until fasting plasma glucose goals are reached, as recommended by the American Diabetes Association 1
• Assess adequacy of insulin dose at every visit 1
• For hypoglycemia: determine cause; if no clear reason, reduce dose by 10-20% 1, 2

Prandial Insulin Therapy

• Start with one dose with the largest meal or meal with greatest postprandial glucose excursion 1, 2
• Initial prandial dose: 4 units per day or 10% of basal insulin dose 1, 2
• Titration: Increase dose by 1-2 units or 10-15% twice weekly 2
• For hypoglycemia: determine cause; if no clear reason, lower corresponding dose by 10-20% 2
• The dose of rapid-acting insulin can be calculated using the formula: (carbohydrates ÷ carbohydrate ratio) + (current glucose - target glucose) ÷ insulin sensitivity factor, to cover carbohydrates and correct hyperglycemia, as recommended by the American Academy of Pediatrics and the American Diabetes Association 4, 5, 6, 7

Conversion to Twice-Daily Regimen and Administration of Pre-Mixed Insulin

• If using bedtime NPH and converting to twice-daily regimen: Total dose = 80% of current bedtime NPH dose, with 2/3 given before breakfast and 1/3 given at bedtime 2
• Administer pre-mixed insulin twice daily: 2/3 before breakfast, 1/3 before dinner 2

Special Considerations

• The use of concentrated insulins (U-200, U-300, U-500) allows for the delivery of higher doses with smaller injection volumes for patients requiring large insulin doses, as stated by the American Diabetes Association 1
• Therapy with corticosteroids may require adjustments in the insulin ratios due to increased insulin resistance, as noted by 5, 7
• When administering rapid-acting insulin, consider the insulin still active from previous doses to avoid stacking doses and the risk of hypoglycemia, as suggested by the British Journal of Anaesthesia 8

Nutrition and Insulin Therapy

• The carbohydrate ratio can be estimated as 1 unit of insulin covering 10-15g of carbohydrates in enteral nutrition, and the insulin sensitivity factor can be estimated by dividing 1800 by the total daily dose (TDD) of insulin, with 1 unit reducing glucose levels by the calculated factor 4, 5, 6, 7
• The following table provides insulin recommendations for different types of nutrition:

Hypoglycemia Risk Management

• Monitor blood glucose regularly to minimize the risk of hypoglycemia 1, 2
• For hypoglycemia: determine cause; if no clear reason, reduce dose by 10-20% 1, 2
• The American Diabetes Association recommends adjusting the insulin dose based on the patient's glucose patterns, with adjustments made to the carbohydrate ratio if postprandial glucose is consistently out of target, and to the insulin sensitivity factor if corrections do not bring glucose to target 9