What alternatives are available if a patient taking Humulin 70/30 (human insulin NPH 70%/regular 30%) 30 units twice daily before meals cannot obtain that specific insulin from the pharmacy?

Alternatives to Humulin 70/30 U-100 When Unavailable

If your pharmacy does not have Humulin 70/30, the most direct alternative is NovoLog Mix 70/30 (or Novolin 70/30), which provides equivalent glycemic control with the same 70% intermediate-acting/30% rapid-acting ratio and can be dosed identically at 30 units twice daily before meals. 1

Direct Substitution: Other Premixed Insulin Products

NovoLog Mix 70/30 (Insulin Aspart Protamine/Insulin Aspart)

• NovoLog Mix 70/30 can be substituted unit-for-unit (30 units twice daily before breakfast and dinner) and provides comparable HbA1c reduction to Humulin 70/30. 1, 2
• This formulation offers superior postprandial glucose control compared to human premixed insulin due to the rapid-acting aspart component, with peak insulin levels reached in half the time. 3, 4
• Administer 0-15 minutes before meals rather than the 30-45 minutes required for Humulin 70/30, providing greater convenience. 5, 4, 6
• Clinical trials demonstrate comparable overall glycemic control and hypoglycemia rates between NovoLog Mix 70/30 and human premixed insulin 70/30. 2, 4, 6

Novolin 70/30 (Human Insulin NPH/Regular)

• Novolin 70/30 is bioequivalent to Humulin 70/30 and can be substituted at the same dose (30 units twice daily). 1
• This is the most direct generic alternative with identical pharmacokinetics to Humulin 70/30. 1

Humalog Mix 75/25 (Insulin Lispro Protamine/Insulin Lispro)

• Contains 75% intermediate-acting and 25% rapid-acting insulin lispro, providing a slightly different ratio than 70/30 formulations. 3, 4
• Can be initiated at 30 units twice daily with adjustment based on glucose monitoring. 3, 7
• Offers improved postprandial control and allows injection immediately before meals. 3, 4, 7

Critical Considerations for Premixed Insulin Use

Lifestyle Requirements

• Meals must be consumed at consistent times every day to match the fixed insulin action profile of premixed formulations. 5
• Patients must eat similar amounts of carbohydrates each day to match the set doses. 5
• Skipping meals dramatically increases hypoglycemia risk because the intermediate-acting component continues working regardless of food intake. 5

When Premixed Insulin Is NOT Appropriate

• Premixed insulin should not be used in hospitalized patients due to unacceptably high hypoglycemia rates (64% vs 24% with basal-bolus therapy in randomized trials). 5, 8
• Patients requiring flexible meal timing or unpredictable eating patterns should use basal-bolus therapy instead. 5
• When total daily premixed insulin exceeds 0.5 units/kg/day without achieving targets, transition to basal-bolus therapy is recommended. 5

Superior Alternative: Transition to Basal-Bolus Therapy

Why Basal-Bolus Is Often Better

• Randomized trials demonstrate basal-bolus therapy provides better glycemic control with reduced hospital complications compared to premixed insulin regimens. 5
• Basal-bolus allows independent adjustment of basal and prandial components, providing greater flexibility and reducing hypoglycemia risk. 1
• This regimen is appropriate for patients who need flexible meal patterns or have variable carbohydrate intake. 5

Conversion from Humulin 70/30 to Basal-Bolus

• Calculate total daily dose: 30 units × 2 = 60 units/day. 1, 9
• Allocate 50% to basal insulin (e.g., insulin glargine): 30 units once daily at bedtime. 1, 9
• Allocate 50% to prandial insulin (e.g., insulin lispro or aspart): 10 units before each of three meals. 1, 9
• Continue metformin at maximum tolerated dose (up to 2000-2550 mg daily) to reduce total insulin requirements by 20-30%. 1

Titration Protocol for Basal-Bolus

• Basal insulin: Increase by 2 units every 3 days if fasting glucose 140-179 mg/dL; increase by 4 units every 3 days if fasting glucose ≥180 mg/dL. 1
• Prandial insulin: Increase each meal dose by 1-2 units every 3 days based on 2-hour postprandial glucose, targeting <180 mg/dL. 1
• Target fasting glucose: 80-130 mg/dL. 1

Monitoring and Safety

Hypoglycemia Management

• Treat any glucose <70 mg/dL immediately with 15-20 grams of fast-acting carbohydrate. 5
• Recheck glucose 15-20 minutes after treatment and repeat if hypoglycemia persists. 5
• If hypoglycemia occurs without obvious cause, reduce the implicated insulin dose by 10-20%. 1

Monitoring Requirements

• Daily fasting and pre-dinner glucose during titration phase. 5
• Check 2-hour postprandial glucose periodically to assess adequacy of rapid-acting component. 5
• Reassess therapy every 3-6 months with HbA1c measurement. 5

Cost Considerations

• Human insulin (NPH and Regular) products, including Humulin 70/30 and Novolin 70/30, can be purchased for considerably less than the average wholesale price at select pharmacies. 1
• NovoLog Mix 70/30 and Humalog Mix 75/25 are typically more expensive but offer convenience of mealtime dosing. 1, 4

Common Pitfalls to Avoid

• Do not mix or dilute premixed insulin with other insulin formulations. 5
• Never use premixed insulin if flexible meal timing is required—basal-bolus therapy is more appropriate. 5
• Do not continue premixed insulin beyond 0.5 units/kg/day without transitioning to basal-bolus therapy. 5
• Avoid using premixed insulin in hospitalized patients due to excessive hypoglycemia risk. 5