You are prescribing rapid acting insulin for a patient newly-diagnosed with type-1 diabetes mellitus. Which of the following is suitable to prescribe?

• A. Insulin lispro
• B. Insulin glargine
• C. Regular insulin
• D. Insulin aspart

Answer: (B)

Understanding how insulin works is essential here. In type 1 diabetes, treatment aims to mimic normal insulin secretion with basal-bolus therapy: a basal insulin provides steady background coverage, while rapid-acting insulins cover meals and correct postprandial spikes.

Long-acting insulin like glargine provides a constant, background effect over about 24 hours and is not used for mealtime coverage. Rapid-acting insulins, such as lispro and aspart, act quickly after injection, peak in about 1–2 hours, and last only a few hours, making them suitable for controlling glucose rise after meals.

Regular insulin has a slower onset and longer duration than rapid-acting insulins, so it’s not the best choice for rapid mealtime coverage with current regimens.

So for rapid-acting needs in a newly diagnosed patient, lispro or aspart would be suitable choices; glargine would be reserved for the basal component of therapy rather than rapid-acting coverage.