Can I use detemir (Levemir) and Lantus (glargine) together?

Using Detemir and Lantus Together

Using detemir (Levemir) and glargine (Lantus) together is not recommended as they are both long-acting basal insulins and would serve redundant purposes in diabetes management. 1, 2

Rationale Against Combined Use

• Long-acting insulin analogs like detemir and glargine are designed to provide basal insulin coverage, and using both simultaneously does not align with physiological insulin requirements 2
• The World Health Organization guidelines indicate that these insulins serve similar functions - providing background insulin coverage with minimal peaks in action 1
• Both insulins have similar pharmacokinetic profiles with onset of action at 2-4 hours and duration of up to 24 hours, making their concurrent use redundant 1
• Standard insulin regimens for diabetes require a combination of basal insulin (like detemir OR glargine) plus prandial insulin coverage, not multiple basal insulins 2

Appropriate Insulin Management

• The recommended approach for type 1 diabetes is to use a single long-acting insulin analog (either detemir OR glargine) for basal coverage, combined with rapid-acting insulin for mealtime coverage 2
• Approximately 50% of daily insulin requirements should be provided as basal insulin and 50% as prandial insulin 2
• Long-acting insulin analogs like detemir and glargine are specifically indicated as part of a regimen that includes mealtime insulin, not in combination with each other 2

Differences Between Detemir and Glargine

• While both are long-acting analogs, they have some clinical differences that may guide the choice of one over the other:
  • Detemir is associated with less weight gain compared to glargine 3
  • Glargine is more likely to be effective with once-daily dosing, while detemir often requires twice-daily administration 3
  • Detemir shows lower within-subject variability and potentially lower risk of hypoglycemia 4

Clinical Considerations

• If current glycemic control is suboptimal with one basal insulin, the appropriate approach is to:
  • Optimize the dose of the current basal insulin
  • Ensure adequate prandial insulin coverage
  • Consider switching to the alternative basal insulin if needed, rather than adding a second one 1, 2
• For patients with type 1 diabetes who experience frequent severe hypoglycemia with human insulin, switching to a long-acting analog is recommended, but still as part of a basal-bolus regimen 1

Potential Risks of Combined Use

• Using two basal insulins together could increase the risk of hypoglycemia 1
• The unpredictable overlap in action times could lead to difficulty in dose titration and glucose management 2
• The combination would not address postprandial glucose excursions, which require rapid-acting insulin 2

The evidence strongly supports using either detemir or glargine as the basal component of insulin therapy, but not both simultaneously, as this approach lacks physiological rationale and could complicate diabetes management without providing additional benefits.