Can Lantus (insulin glargine) be given with Novolog 70/30 (insulin aspart protamine/insulin aspart)?

Lantus Should Not Be Given with Novolog 70/30

Insulin glargine (Lantus) should not be mixed with other forms of insulin, including Novolog 70/30, due to the low pH of its diluent which can affect the pharmacokinetics of other insulins. 1

Rationale for Not Mixing Lantus with Other Insulins

• Insulin glargine has a unique formulation with an acidic pH (4.0) that is essential for its stability and prolonged action profile 2
• When mixed with other insulins, physicochemical changes can occur that alter the pharmacokinetic properties of both insulins, potentially leading to unpredictable glucose control 1
• The American Diabetes Association explicitly states that insulin glargine should not be mixed with other forms of insulin 1
• The FDA label for Lantus specifically warns against diluting or mixing Lantus with any other insulin or solution 3

Proper Administration of These Insulins

• Lantus (insulin glargine) should be administered as a separate injection once daily at the same time each day 3
• Novolog 70/30 (insulin aspart protamine/insulin aspart) is typically administered twice daily, before breakfast and dinner 4, 5
• When using both types of insulin in a regimen, they should be administered as separate injections 1, 3

Clinical Implications

• Using both insulins in a regimen (but as separate injections) can provide complementary coverage:
  • Lantus provides consistent 24-hour basal insulin coverage with no pronounced peak 6
  • Novolog 70/30 provides both intermediate-acting and rapid-acting components to cover basal and prandial needs 4
• Premixed insulins like Novolog 70/30 offer the advantage of fewer daily injections while providing both basal and prandial coverage 4, 5
• Basal insulins like Lantus may be used in combination with premixed insulins, but must be administered separately 1

Potential Alternatives

• If simplification of the regimen is desired, consider:
  • Using only Novolog 70/30 twice daily (before breakfast and dinner) 1, 4
  • Using Lantus once daily plus rapid-acting insulin (like regular Novolog) before meals 1
• When switching between insulin regimens, maintain the same total daily dose initially but adjust the distribution appropriately 7
• More frequent blood glucose monitoring is essential during any transition period between insulin regimens 7, 8

Common Pitfalls to Avoid

• Never mix Lantus in the same syringe with any other insulin 1, 3
• Avoid converting between insulin regimens on a 1:1 basis without considering appropriate dose adjustments 7, 8
• Don't neglect more frequent blood glucose monitoring during transition periods between insulin regimens 7
• Remember that meal timing becomes more critical with premixed insulins compared to basal-bolus regimens 7, 8