What are the typical insulin dosages for type 1 and type 2 diabetes?

Typical Insulin Dosages for Type 1 and Type 2 Diabetes

For patients with type 1 and type 2 diabetes, basal insulin should be initiated at 10 units per day or 0.1-0.2 units/kg/day, with prandial insulin starting at 4 units or 10% of the basal dose per meal. 1

Initial Insulin Dosing

Type 1 Diabetes

• Basal insulin: Approximately one-third of total daily insulin requirements 2
• Prandial insulin: Remaining two-thirds of total daily insulin requirements
• Total starting dose: 0.5 units/kg/day 3
• Must always be used with short-acting insulin 2

Type 2 Diabetes

• Basal insulin: 10 units per day or 0.1-0.2 units/kg/day 1
• Prandial insulin (when needed): 4 units per meal, 0.1 units/kg per meal, or 10% of basal dose per meal 1
• Total daily dose when insulin resistance present: Often ≥1 unit/kg 1

Insulin Titration Guidelines

Basal Insulin Titration

Adjust every 3 days based on fasting blood glucose (FBG) patterns 3:

• FBG ≥180 mg/dL: Increase by 6-8 units
• FBG 140-179 mg/dL: Increase by 4 units
• FBG 120-139 mg/dL: Increase by 2 units
• FBG 100-119 mg/dL: Maintain or increase by 0-2 units
• FBG <100 mg/dL: Decrease by 2-4 units
• Any hypoglycemia (<70 mg/dL): Decrease by 10-20%

Prandial Insulin Titration

Adjust each meal dose separately based on 2-hour postprandial glucose (PPG) patterns 3:

• PPG >200 mg/dL: Increase by 2-4 units
• PPG 150-200 mg/dL: Increase by 1-2 units
• PPG 100-150 mg/dL: No change
• PPG <100 mg/dL: Decrease by 1-2 units
• Any hypoglycemia: Decrease corresponding meal dose by 10-20%

Special Insulin Formulations

Concentrated Insulins

• U-500 regular insulin: For patients requiring >200 units/day 1
• U-300 glargine and U-200 degludec: Allow higher doses with less volume 1
• U-200 lispro: May improve adherence for those requiring large doses 1

Premixed Insulin

• Contains fixed proportions of basal and prandial insulin 1
• Simplifies dosing but requires relatively fixed meal schedule and carbohydrate content 1
• Examples: NPH/Regular 70/30 (70% NPH, 30% regular insulin) 1

Clinical Considerations

Switching Between Insulin Types

When switching from:

• TOUJEO (U-300 glargine) to U-100 glargine: Use 80% of previous dose 2
• Once-daily NPH to once-daily glargine: Same dose 2
• Twice-daily NPH to once-daily glargine: 80% of total NPH dose 2

Combination Therapy

• When adding prandial insulin to basal insulin, consider decreasing basal insulin dose if A1C is <8% 1
• Consider GLP-1 receptor agonists before adding prandial insulin to basal insulin 1

Common Pitfalls to Avoid

1. Overbasalization: Signs include basal dose >0.5 units/kg, high bedtime-morning glucose differential (≥50 mg/dL), or hypoglycemia 1
2. Insulin stigmatization: Avoid using insulin as a threat or describing it as a sign of personal failure 1
3. Inadequate monitoring: Blood glucose monitoring is essential for insulin dose adjustments 3, 4
4. Injection site issues: Rotate injection sites to prevent lipohypertrophy, which can affect insulin absorption 3, 2
5. Cost barriers: Consider cost when selecting insulin products, as prices have increased substantially 1

Patient Education

• Equip patients with self-titration algorithms based on blood glucose monitoring 1
• Provide comprehensive education on hypoglycemia recognition and management 3
• Ensure consistent meal timing and carbohydrate content to match insulin action 3

By following these dosing guidelines and considering individual patient factors, clinicians can effectively initiate and adjust insulin therapy to achieve optimal glycemic control while minimizing the risk of hypoglycemia.