Which of the following is a rapid acting insulin drug?

Lispro, commonly known by its brand name Humalog, is classified as a rapid-acting insulin. Rapid-acting insulins are designed to quickly manage blood glucose levels by mimicking the body's natural insulin response to meals. They typically start to take effect within 15 minutes after injection, peak in about 1 to 2 hours, and can last for approximately 3 to 5 hours.

Understanding the pharmacokinetics of different insulin types is crucial for effective diabetes management. On the contrary, Lantus and Glargine are both formulations of long-acting insulin, providing a steady release of insulin to help control blood sugar levels over a 24-hour period without significant peaks. NPH, on the other hand, is an intermediate-acting insulin that has a longer onset and can lead to peaks and duration that differ, making it less effective for immediate post-meal blood sugar control compared to rapid-acting insulins. Thus, the rapid onset and short duration of Lispro make it the correct choice for this question regarding rapid-acting insulin drugs.