Which local anesthetic has the shortest duration when administered in a local anesthetic block?

The local anesthetic with the shortest duration when administered in a block is mepivacaine, particularly in its 3% formulation. Mepivacaine has a relatively quick onset and a duration of action that generally ranges from 1 to 2 hours when used for nerve blocks. This is shorter compared to other anesthetics like bupivacaine, which can provide analgesia for several hours, or lidocaine and articaine, which typically have intermediate durations of action ranging from about 2 to 3 hours under similar conditions.

The choice of mepivacaine can be particularly beneficial in certain clinical scenarios where a shorter duration of anesthesia is desired, such as in outpatient procedures or when postoperative pain management is required without prolonged numbness. Understanding the pharmacokinetic profiles of these agents helps practitioners select the most appropriate anesthetic for their patients' needs.