What is the initial dosing for insulin therapy?

Initial Insulin Dosing Guidelines

The recommended starting total daily insulin dose is typically weight-based, ranging from 0.4 to 1.0 units/kg of body weight, with 0.5 units/kg being the typical starting dose for metabolically stable patients with type 1 diabetes. 1

Type 1 Diabetes Initial Dosing

• The starting total daily insulin dose for type 1 diabetes typically ranges from 0.4 to 1.0 units/kg of body weight 1
• A typical total daily starting dose in metabolically stable patients is 0.5 units/kg 1
• Higher weight-based starting doses may be needed for patients who present with diabetic ketoacidosis 1
• Higher insulin doses are often required during puberty 1
• The total daily insulin dose should be divided with approximately one-third (or 50%) as basal insulin and the remainder as prandial insulin 1, 2

Type 2 Diabetes Initial Dosing

• For insulin-naive type 2 diabetes patients, the recommended starting dose is 0.1-0.2 units/kg/day or up to 10 units once daily 1, 2
• Basal insulin alone is the most convenient initial insulin regimen for type 2 diabetes, beginning at 10 units or 0.1-0.2 units/kg, depending on the degree of hyperglycemia 1, 3
• Basal insulin is usually prescribed in conjunction with metformin and possibly one additional non-insulin agent 1, 3

Insulin Regimen Selection

• Most patients with type 1 diabetes should be treated with multiple daily injections (MDI) of both prandial and basal insulin or with continuous subcutaneous insulin infusion (CSII) 1
• Most patients should use rapid-acting insulin analogs to reduce hypoglycemia risk 1
• For type 2 diabetes, basal insulin alone is typically the initial regimen, with prandial insulin added if glycemic targets are not achieved 1

Dose Titration

• For basal insulin in type 2 diabetes, increase the dose by 2-4 units every 3-4 days until fasting blood glucose reaches target range (80-130 mg/dL) 3
• For more aggressive titration, doses can be increased by 10-15% or 2-4 units once or twice weekly until fasting blood glucose target is met 3
• Self-titration of insulin doses based on self-monitoring of blood glucose improves glycemic control 1

Special Considerations

• For patients on enteral/parenteral feeding requiring insulin, a reasonable starting point is 10 units of insulin glargine every 24 hours 3
• For patients transitioning from other insulin therapies to insulin glargine, dosage adjustments are recommended to lower the risk of hypoglycemia 2:
  • When switching from once-daily NPH insulin to once-daily insulin glargine, use the same dosage
  • When switching from twice-daily NPH insulin to once-daily insulin glargine, use 80% of the total NPH dosage

Common Pitfalls to Avoid

• Delaying insulin therapy in patients not achieving glycemic goals 3
• Not adjusting doses based on self-monitoring of blood glucose levels 3
• Overbasalization - using higher than necessary basal insulin doses that can mask insufficient mealtime insulin coverage 3
• Failure to recognize that insulin requirements may change with weight changes, illness, or changes in physical activity 3

By following these evidence-based guidelines for initial insulin dosing, clinicians can help patients achieve optimal glycemic control while minimizing the risk of hypoglycemia and other adverse effects, ultimately improving morbidity, mortality, and quality of life outcomes.