Medicine & USMLE

Long Acting Insulin

Anti-Diabetic Drugs
  1. Insulin Overview
  2. Rapid Acting Insulin
  3. Short Acting Insulin
  4. Intermediate Acting Insulin
  5. Long Acting Insulin
  6. Metformin
  7. Sulfonylureas
  8. Canagliflozin
  9. Pioglitazone


Long-acting insulins include the drugs glargine and detemir. Long acting insulins are given once daily, have no peak, and instead work steadily over a duration of around 24 hours. Long acting insulins cannot be mixed; they must be given in their own syringe.

Key Points

  • Long Acting Insulin
    • Drug Names
      • Glargine (Lantus)
      • Detemir (Levemir)
    • Onset, Peak, Duration
      • Onset = 1-2 hours
      • Peak = ~1 day (no peak)
        • Exact peak for detemir depends on patient and ranges from 4-9 hours
        • Glargine’s peak is so slow and long (>12 h) that there is no apparent peak in dose
      • Duration = up to 24 hours
    • Nursing Considerations
      • Cannot be mixed
        • Never mix long-acting insulins with other insulin formulations (e.g. regular insulin)
      • Inject once daily, at the same time each day
      • Given to prevent, not correct, hyperglycemia
        • Long peak is intended to counteract baseline production of glucose by liver