Final answer:
The local anesthetic with the longest lasting effects is typically bupivacaine, providing analgesia that can last for several hours, depending on the technique of administration and potential combination with other substances.
Step-by-step explanation:
The local anesthetic with the longest lasting analgesic effects will typically be a long-acting agent. One of the more commonly used long-acting local anesthetics is bupivacaine. Such drugs are often used in procedures where prolonged pain relief is desired, like certain surgical or dental procedures. Bupivacaine has the advantage of providing extended periods of analgesia, which can last for several hours. It works by blocking nerve signals in your body, which makes it an effective local anesthetic. However, it is worth noting that the duration of analgesic effects can also be affected by the technique of delivery, such as the use of nerve blocks, and whether or not the anesthetic is combined with other substances like epinephrine which can prolong its action.