Which anesthetic corresponds to a 1% solution with max dose 5-7 mg/kg and onset of 2-5 minutes, duration 60-180 minutes?

• A. Lidocaine 1%
• B. Procaine 1%
• C. Mepivacaine 1%
• D. Lidocaine with epinephrine 1% + 1:200,000 epi

Answer: (D)

This question is about how adding epinephrine to a local anesthetic changes how much you can safely use and how long it lasts. Lidocaine at 1% is a common fast-onset local anesthetic, with typically a 2–5 minute onset. When you mix it with epinephrine, the vasoconstrictor tightens blood vessels, which slows the drug’s absorption into the bloodstream. That means you can safely use a higher total dose per kilogram and the anesthetic stays effective in the tissue longer. That combination yields a max dose around 5–7 mg/kg and a duration commonly in the 60–180 minute range.

So, among the options, the one that matches lidocaine at 1% with epinephrine 1:200,000 and the described dosing and duration is the preparation that includes epinephrine. Procaine and mepivacaine have different dosing limits and typically different onset and duration profiles, and without vasoconstrictor, the duration would generally be shorter. The presence of epinephrine best explains the higher max dose and the longer duration given.