A local anesthetic (LA) is a medication that causes absence of all sensation (including pain) in a specific body part without loss of consciousness,[1] providing local anesthesia, as opposed to a general anesthetic, which eliminates all sensation in the entire body and causes unconsciousness.[1] Local anesthetics are most commonly used to eliminate pain during or after surgery.[2] When it is used on specific nerve pathways (local anesthetic nerve block), paralysis (loss of muscle function) also can be induced.[3]