The nurse administers 10 units of NPH insulin at 7 a.m. At what time does the nurse expect the patient to experience the peak benefit of the NPH insulin?

Choice A rationale The onset of action for NPH insulin is typically 1.5 to 4 hours after administration. A peak at 8 a.m. would be too early, as it is only one hour after the injection time of 7 a.m. This timing would be more characteristic of a rapid-acting insulin such as lispro (Humalog) or aspart (Novolog). Choice B rationale NPH insulin is an intermediate-acting insulin. Its pharmacokinetics are characterized by a typical onset of 1.5 to 4 hours, a peak effect of 4 to 12 hours, and a duration of 14 to 24 hours. Given a 7 a.m. administration, the peak benefit is expected within the 4-12 hour window, making 10 a.m. a plausible time for the peak. Choice C rationale A peak at 5 p.m. would represent 10 hours post-administration, which falls within the typical 4-12 hour peak range for NPH insulin. However, 10 a.m. (3 hours post-administration) is also within the peak window and a more common early peak time. Both B and C are scientifically plausible, but 10 a.m. is a more representative average early peak. Choice D rationale A peak at 11: p.m. would be 16.5 hours after the 7 a.m. administration. This time is well outside the typical 4 to 12-hour peak range for NPH insulin. By 11: p.m., the insulin's effect would likely be waning or nearing the end of its duration of action.