From the Guidelines
NPH insulin has a duration of action of approximately 12 hours. The onset of action for NPH insulin is around 1 hour, with a peak effect between 6 to 8 hours after administration 1. This intermediate-acting insulin is often used to provide basal insulin coverage, and its duration can vary between individuals based on factors such as injection site, dose, and individual metabolism. Some key characteristics of NPH insulin include:
- Onset of action: 1 hour
- Peak effect: 6 to 8 hours
- Duration of action: 12 hours
- Cost: estimated $35 for a 10-mL vial, based on average wholesale prices in 2006 1. It is essential for patients to be aware of the peak action period of NPH insulin, as it may cause hypoglycemia if not matched with appropriate food intake. For complete 24-hour coverage, NPH is often prescribed twice daily, typically before breakfast and at bedtime, and blood glucose should be monitored frequently to establish the individual response pattern and adjust dosing accordingly.
From the Research
Duration of Action of NPH Insulin
- The duration of action of NPH insulin is estimated to be around 13 hours, with an onset of 3 hours and a peak of 6-7 hours 2.
- This estimate is based on a study that used pharmacodynamic modeling to establish time-action profiles for regular and NPH insulin.
- Another study compared the safety and efficacy of three basal-bolus regimens of NPH/regular insulin in the management of inpatient hyperglycemia, but did not specifically report on the duration of action of NPH insulin 3.
- Other studies have reported on the use of NPH insulin in various clinical settings, including steroid-induced hyperglycemia 4 and type 2 diabetes mellitus 5, but did not provide specific information on the duration of action of NPH insulin.
- A study comparing insulin glargine and NPH insulin as basal insulin for the treatment of glucocorticoid-induced hyperglycemia in hospitalized patients with type 2 diabetes and respiratory disease did not report on the duration of action of NPH insulin 6.