At what time is hypoglycemia likely to occur with NPH insulin?

Hypoglycemia is likely to occur with NPH insulin primarily in the afternoon, particularly around 3 PM, leading into dinner time. NPH insulin is an intermediate-acting insulin that typically has a peak action time between 4 to 8 hours after injection. If a person administers NPH insulin in the morning, the peak action period aligns with the afternoon, which is when blood glucose levels can drop significantly if not properly managed with food intake or additional carbohydrates.

The peak effect coincides with common meal times, and if a meal is skipped or insufficiently balanced with carbohydrates, the risk of hypoglycemia increases. Monitoring for symptoms during this timeframe is crucial to avoid drops in blood glucose levels that could lead to hypoglycemic events.

Other time periods provided do not align with the pharmacokinetics of NPH insulin. Before breakfast would occur before the insulin has a significant impact, immediately after meals would be during the rising action of the insulin rather than a drop, and before bed would not be the peak time for NPH. Therefore, the timing associated with the peak action of NPH insulin clearly indicates that the risk of hypoglycemia is most significant in the afternoon before dinner.