Starting Dose for 70/30 Insulin
For insulin-naïve patients with type 2 diabetes, start 70/30 insulin at 10 units or 0.1-0.2 units/kg body weight per day, divided into two equal doses given 30 minutes before breakfast and dinner. 1, 2
Initial Dosing Strategy
The most straightforward approach for patients failing oral medications is to begin with 10 units twice daily (before breakfast and dinner), which provides a safe starting point regardless of body weight 1. This conservative dose minimizes hypoglycemia risk while establishing the insulin regimen 2.
For patients who prefer weight-based dosing, use 0.1-0.2 units/kg/day divided into two equal doses 1, 2. This translates to approximately:
- 70 kg patient: 7-14 units total daily (3.5-7 units per injection)
- 90 kg patient: 9-18 units total daily (4.5-9 units per injection)
Patients with type 2 diabetes typically require ≥1 unit/kg/day at steady state, but starting lower prevents hypoglycemia during the titration phase 2.
Administration Timing
Administer doses 30 minutes before breakfast and 30 minutes before dinner 1, 2. This timing is critical—premixed insulin requires consistent meal timing to avoid hypoglycemia 3. The fixed ratio of rapid-acting and intermediate-acting components means patients must eat within the specified timeframe after injection 3.
Titration Protocol
After establishing the starting dose, implement systematic titration every 2-3 days 1, 2:
Target fasting blood glucose: 80-110 mg/dL 1, 2
- If ≥50% of fasting glucose readings exceed target: increase dose by 2 units 2
- If >2 fasting readings per week are <80 mg/dL: decrease dose by 2 units 2
- Evaluate glycemic control every 2 weeks and adjust accordingly 1
Research demonstrates that starting with once-daily 70/30 insulin (12 units before dinner) achieved HbA1c <7% in 41% of patients, while twice-daily dosing increased success to 70% 4. This supports the twice-daily starting approach recommended in current guidelines.
Special Populations Requiring Lower Starting Doses
Use lower starting doses (closer to 0.1 units/kg/day or even less) for 2:
- Age >65 years
- Renal impairment (any degree)
- Poor or unpredictable oral intake
- History of hypoglycemia
These patients face substantially higher hypoglycemia risk and require more conservative titration 2.
Transitioning from Other Insulin Regimens
For patients already on basal insulin, the American College of Endocrinology recommends maintaining the same total daily dose initially, distributing approximately 2/3 before breakfast and 1/3 before dinner 3. However, the American Association of Clinical Endocrinologists suggests dividing the total daily dose into two equal doses when transitioning 1. The 2/3-1/3 split reflects typical insulin requirements but may require adjustment based on individual glucose patterns 3.
Critical Safety Considerations
Do not mix 70/30 insulin with other insulins in the same syringe, particularly glargine 3. The premixed formulation is designed as a complete product and mixing alters its pharmacokinetic profile 3.
Discontinue sulfonylureas when starting 70/30 insulin to reduce hypoglycemia risk 2. Continue metformin as it provides complementary insulin sensitization without increasing hypoglycemia 2, 5.
Monitor blood glucose more frequently during the first 2-4 weeks, focusing on both fasting and postprandial values 3. This is when hypoglycemia risk peaks as doses are being established 3.
When to Intensify Beyond Starting Dose
If HbA1c remains >7% after 16 weeks of optimized twice-daily dosing, consider 1, 4:
- Adding a third injection (6 units before lunch) 4
- Switching to basal-bolus regimen for more precise control 2
- Adding GLP-1 receptor agonist to reduce insulin requirements 1, 2
Research shows that adding a third daily injection of 70/30 insulin achieved HbA1c <7% in 77% of patients who failed twice-daily dosing 4. However, this increases complexity and hypoglycemia risk 4.
Common Pitfalls to Avoid
Do not use the same dose for morning and evening injections without assessing individual patterns—while equal dosing is the starting point, most patients ultimately require higher morning doses 3.
Do not continue escalating 70/30 insulin indefinitely if targets aren't met—this represents therapeutic inertia and increases hypoglycemia without proportional benefit 2. When doses exceed 0.5 units/kg/day, consider regimen intensification or adding non-insulin agents 2.
Avoid premixed insulin in patients with unpredictable eating patterns—the fixed ratio limits flexibility and substantially increases hypoglycemia risk 2.
Human regular/NPH 70/30 products (Novolin, Humulin) can be purchased at significantly lower cost than analog premixed insulins at select pharmacies, making them accessible options for cost-conscious patients 6.