What is the initial dosage of Mixtard (biphasic insulin) based on blood glucose levels?

Mixtard Insulin Dosing Based on Blood Glucose Levels

The initial dosage of Mixtard (biphasic insulin) should be 0.1-0.2 units/kg/day, administered twice daily, with dose adjustments based on blood glucose monitoring. 1

Initial Dosing Algorithm

When starting Mixtard insulin therapy:

1. Calculate weight-based starting dose:

   • Start with 0.1-0.2 units/kg/day total daily dose 1
   • Divide into two equal doses (pre-breakfast and pre-dinner)

2. Blood glucose-based adjustments:

   • For patients with blood glucose ≥300 mg/dL or HbA1c ≥9%: Consider starting at the higher end of the range (0.2 units/kg/day) 1
   • For elderly patients or those at higher risk of hypoglycemia: Start at the lower end (0.1 units/kg/day) 1

Dose Titration Protocol

• Adjust dose every 3 days based on blood glucose patterns 1
• Target fasting glucose: 80-130 mg/dL 1
• Dose adjustments:
  • If fasting glucose consistently >130 mg/dL: Increase evening dose by 2 units
  • If pre-dinner glucose consistently >130 mg/dL: Increase morning dose by 2 units
  • If hypoglycemia occurs: Reduce corresponding dose by 10-20% 1

Mixtard Formulation Selection

Mixtard is available in different fixed-ratio formulations:

• Mixtard 30 (30% regular insulin, 70% NPH)
• Mixtard 50 (50% regular insulin, 50% NPH)

Selection should be based on blood glucose patterns:

• Mixtard 30: Standard starting formulation for most patients
• Mixtard 50: Consider for patients with significant post-breakfast hyperglycemia 2

Special Considerations

• Hypoglycemia risk: Monitor closely during initiation and dose adjustments
• Meal timing: Administer 15-30 minutes before meals
• Blood glucose monitoring: Check glucose before breakfast, before lunch, before dinner, and at bedtime initially

Correction Doses for Hyperglycemia

For blood glucose >180 mg/dL, consider adding rapid-acting insulin 1:

• 150-200 mg/dL: Add 2 units
• 201-250 mg/dL: Add 4 units
• 251-300 mg/dL: Add 6 units

• 300 mg/dL: Add 8 units and notify provider

Common Pitfalls to Avoid

1. Inappropriate timing: Ensure Mixtard is administered 15-30 minutes before meals
2. Fixed dosing: Failure to adjust doses based on blood glucose patterns
3. Inadequate monitoring: Insufficient blood glucose checks during initiation phase
4. Ignoring hypoglycemia: Failure to reduce dose after hypoglycemic events
5. Overlooking patient education: Patients need instruction on injection technique, site rotation, and hypoglycemia management

While premixed insulin analogues like Mixtard provide convenience with fewer daily injections, they offer less flexibility than basal-bolus regimens. For patients requiring tighter glycemic control, multiple daily injections with separate basal and bolus insulins may eventually be needed 3, 1.