A nurse is preparing to administer regular insulin to a client before lunch. If the insulin is given at 11:00 AM, at what time should the nurse expect the medication to peak?

Rationale: A. A peak at 3:00 PM would be 4 hours after the 11:00 AM dose, which is longer than the typical peak range for regular insulin. This timing is more consistent with long-acting insulin preparations, which are designed to have a slow, sustained effect and are not intended to manage postprandial glucose spikes. Administering regular insulin requires monitoring during its actual peak period to prevent hypoglycemia. B. Although regular insulin has an onset of action of about 30–60 minutes, the insulin is only beginning to lower blood glucose levels at 11:30 AM. This is too early to reflect the maximum blood-glucose-lowering effect, so monitoring for hypoglycemia at this time would not capture the peak risk period. C. Regular insulin administered subcutaneously at 11:00 AM typically has an onset of 30–60 minutes, a peak effect at 2–4 hours, and a duration of 5–8 hours. Therefore, the peak effect would occur approximately 2 hours after administration, around 1:00 PM. This is the time when the insulin is most active and the patient is at highest risk for hypoglycemia. It is essential for the nurse to educate the patient about monitoring blood glucose, recognizing signs of hypoglycemia, and having fast-acting carbohydrates available during this period. Proper timing of meals and monitoring aligns with the pharmacokinetics of the medication, ensuring safe and effective blood glucose control. D. Twelve noon is one hour after the 11:00 AM injection, which corresponds to the early action phase of regular insulin. At this point, the medication has begun to lower blood glucose, but it has not yet reached its peak activity, so this is not the period of highest hypoglycemia risk. Monitoring exclusively at this time could miss the true peak and underestimate patient risk.