Which insulin preparation has the slowest onset and longest acting profile?

Which insulin preparation has the slowest onset and longest acting profile?

• A. Glargine (Lantus)
• B. Lispro (Humalog)
• C. Regular (Humulin-R)
• D. Ultralente

Answer: (D)

Understanding how insulin preparations differ in onset and duration helps explain why ultralente fits this question. Among the insulins listed, rapid-acting types like lispro act within minutes and last only a couple of hours. Regular insulin starts working in about 30 to 60 minutes and lasts roughly 6 to 8 hours. Glargine is long-acting with a steady effect over about 24 hours, starting in roughly 1 to 2 hours. Ultralente, on the other hand, has the slowest onset, taking several hours to begin lowering glucose, and provides action for the longest duration, often around a day or more. Because it combines the slowest start with the longest effect, ultralente is the best answer here.

Understanding how insulin preparations differ in onset and duration helps explain why ultralente fits this question. Among the insulins listed, rapid-acting types like lispro act within minutes and last only a couple of hours. Regular insulin starts working in about 30 to 60 minutes and lasts roughly 6 to 8 hours. Glargine is long-acting with a steady effect over about 24 hours, starting in roughly 1 to 2 hours. Ultralente, on the other hand, has the slowest onset, taking several hours to begin lowering glucose, and provides action for the longest duration, often around a day or more. Because it combines the slowest start with the longest effect, ultralente is the best answer here.