Medicine & USMLE

Intermediate 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


Intermediate acting insulin formulations include NPH insulin. This type of insulin works slower than rapid or short-acting insulins but faster than long-acting insulins, with a peak time averaging around 5 hours after administration. Remember that NPH has a cloudy appearance and that when mixed with regular insulin, it should be drawn up in the syringe last, after regular insulin has already been drawn.

Key Points

  • Intermediate Acting Insulin
    • Drug Names
      • NPH (Humulin N, Novolin N)
    • Onset, Peak, Duration
      • Onset = 1.5-4 hours
      • Peak = ~5 hours
        • Exact peak depends on patient and ranges from 4-12 hours
      • Duration = 12-18 hours
    • Nursing Considerations
      • Cloudy” in appearance
      • When mixing with Regular insulin, draw NPH insulin LAST
        • Clear before cloudy, or “RN” - regular before NPH