Actrapid is a Prandial (Mealtime) Insulin
Actrapid (human regular insulin) is a prandial insulin used to control postprandial glucose excursions, not a basal insulin. It is designed to be administered before meals to manage blood glucose after eating 1.
Pharmacokinetic Profile
Actrapid is a short-acting human insulin with distinct characteristics that define its role as prandial coverage:
- Onset and Duration: Regular human insulin like Actrapid has a slower onset and longer duration of action compared to rapid-acting analogs, but it is still fundamentally a mealtime insulin 1, 2.
- Timing of Administration: Actrapid should ideally be administered 30 minutes before meals for optimal postprandial glucose control, whereas rapid-acting analogs can be given immediately before eating 3, 4.
- Peak Action: The insulin reaches peak levels more slowly than rapid-acting analogs, which is why the 30-minute pre-meal timing is recommended 3.
Clinical Use in Insulin Regimens
In typical multidose treatment plans, Actrapid serves as the prandial component combined with a longer-acting basal formulation 1:
- Basal insulin (NPH, glargine, detemir, or degludec) is titrated to regulate overnight and fasting glucose 1.
- Prandial insulin like Actrapid manages postprandial glucose excursions when administered before meals 1.
- In type 1 diabetes, approximately 30-50% of daily insulin is given as basal, with the remainder as prandial insulin 1.
Comparison to Modern Alternatives
While Actrapid remains effective, rapid-acting analogs (lispro, aspart, glulisine) offer clinical advantages over regular human insulin 2, 5:
- Faster onset of action with reduced tendency to aggregate as hexamers 2.
- Better postprandial glucose control when given immediately before meals 3, 6.
- More physiological insulin profiles that closely mimic endogenous prandial secretion 6, 4.
Studies demonstrate that when Actrapid is injected 30 minutes before a meal, it achieves similar postprandial control to rapid-acting analogs given immediately pre-meal 3. However, immediate pre-meal administration of Actrapid results in inferior glucose control compared to both properly timed Actrapid and rapid-acting analogs 3.
Common Pitfall to Avoid
Do not confuse Actrapid with basal insulin or use it for basal coverage. Regular human insulin is not suitable for providing consistent 24-hour basal insulin levels 7. True basal insulins like glargine, detemir, degludec, or NPH should be used for basal-only coverage due to their pharmacokinetic profiles 7.