A snack should be scheduled for a patient on isophane insulin suspension (NPH) during which part of the day?

• A. One-half hour prior to the dose
• B. Immediately after the dose
• C. Mid-afternoon
• D. Every two hours during the daytime

Answer: (C)

Isophane insulin suspension (NPH) is an intermediate-acting insulin. It starts to lower blood glucose after about 1–2 hours, reaches a peak several hours later, and then lasts for many hours. The risk of hypoglycemia is greatest during this peak, so a snack is timed to cover that period of maximum insulin activity. If the morning dose is given, the peak tends to occur in the late morning to mid-afternoon, making a snack in the mid-afternoon the best choice to help prevent low blood glucose during the peak. Snacking just before the dose targets onset, snacking immediately after misses the peak coverage, and snacking every two hours is unnecessary for this insulin’s action profile.