What is the recommended insulin dosing schedule for patients requiring insulin therapy?

Recommended Insulin Dosing Schedule for Patients Requiring Insulin Therapy

The recommended insulin dosing schedule for patients requiring insulin therapy is a basal-bolus approach, with basal insulin given once or twice daily along with rapid-acting insulin before meals, plus corrective doses of rapid-acting insulin as needed. 1

Initial Insulin Dosing

For Insulin-Naïve Patients with Type 2 Diabetes:

• Start with basal insulin at 10 units per day or 0.1-0.2 units/kg/day 1, 2
• Set fasting plasma glucose target and choose an evidence-based titration algorithm 1
• Increase dose by 2 units every 3 days to reach fasting glucose target without hypoglycemia 1
• For hypoglycemia: determine cause; if no clear reason, lower dose by 10-20% 1

For Patients with Type 1 Diabetes:

• Approximately one-third of total daily insulin requirements should be basal insulin 2
• Must use short-acting, premeal insulin to satisfy the remainder of daily insulin requirements 2
• Sliding scale insulin alone should never be used in patients with type 1 diabetes 1

Basal-Bolus Regimen

Dosing Structure:

• For insulin-naive patients or those on low doses: total daily insulin dose between 0.3-0.5 units/kg 1
• Half of total daily insulin dose allocated to basal insulin (1-2 times daily) 1
• Other half allocated to rapid-acting insulin (divided three times daily before meals) 1
• Lower doses for patients with higher hypoglycemia risk (older patients >65 years, renal failure, poor oral intake) 1

For Patients on Higher Insulin Doses:

• For patients treated with higher doses of insulin at home (≥0.6 units/kg/day), reduce total daily insulin dose by 20% while in hospital to prevent hypoglycemia 1

Basal-Plus Approach

• Preferred for patients with mild hyperglycemia, decreased oral intake, or undergoing surgery 1
• Consists of a single dose of basal insulin (0.1-0.25 units/kg/day) 1
• Add corrective doses of insulin for increased glucose before meals or every 6 hours if nil by mouth 1
• Recommended for patients with diabetes who are fasting or expected to undergo procedures 1

Prandial (Bolus) Insulin

• Recommended starting dose: 4 units, 0.1 units/kg, or 10% of the basal dose 1
• If A1C <8% when starting mealtime bolus insulin, consider decreasing the basal insulin dose 1
• Rapid-acting analogs are preferred due to their prompt onset of action 1
• Increase dose by 1-2 units or 10-15% twice weekly based on blood glucose response 1

Important Considerations

Transitioning Between Insulin Regimens:

• When switching from intravenous to subcutaneous insulin, estimate requirements based on the average amount infused during the previous 12 hours 1
• When switching from twice-daily NPH to once-daily glargine, the recommended starting glargine dosage is 80% of the total NPH dosage 2

Avoiding Hypoglycemia:

• The basal-bolus approach is associated with a 4-6 times higher risk of hypoglycemia compared to sliding scale insulin therapy 1
• In controlled settings, the incidence of mild iatrogenic hypoglycemia with basal-bolus is about 12-30% 1
• For patients at high risk of hypoglycemia, consider the basal-plus approach instead of full basal-bolus 1

Regimens to Avoid:

• Premixed insulin therapy (human insulin 70/30) has been associated with an unacceptably high rate of hypoglycemia and is not recommended in the hospital setting 1
• Sliding scale insulin alone is associated with clinically significant hyperglycemia in many patients and its use has been discouraged except in patients without diabetes who have mild stress hyperglycemia 1

Special Situations

For Patients Receiving Enteral Nutrition:

• Use basal insulin (isophane insulin every 8h, detemir every 12h, or glargine every 24h) along with short-acting insulin every 4-6 hours 1
• If tube feeding is interrupted, start intravenous 10% dextrose infusion at 50 mL/h 1

For Patients on Glucocorticoids:

• For patients without diabetes receiving high-dose steroids, a single dose of isophane insulin in the morning might be appropriate 1
• For patients with diabetes on insulin therapy, addition of isophane insulin (0.1-0.3 units/kg/day) to usual insulin regimen can significantly improve glycemic control 1

Self-Management Education:

• Equip patients with an algorithm for self-titration of insulin doses based on self-monitoring of blood glucose 1
• Provide comprehensive education regarding self-monitoring, diet, and hypoglycemia management 1