What is the duration of action for mepivacaine when used in a nerve block?

When mepivacaine is utilized in a nerve block, it typically has a duration of action that ranges from 90 to 180 minutes. This duration is influenced by factors such as the specific formulation of mepivacaine used (plain vs. with a vasoconstrictor), the site of the injection, and individual patient factors. Mepivacaine is known for providing effective anesthesia with a relatively quick onset and moderate duration, making it suitable for various dental and surgical procedures.

Other durations provided, such as 60 minutes, 3-5 hours, and 5-8 hours, do not accurately reflect the clinical use of mepivacaine in nerve blocks. Specifically, 60 minutes would be too short for its intended applications, while 3-5 hours and 5-8 hours suggest a prolonged effect that is more characteristic of other anesthetics or injections with added vasoconstrictors that protract the anesthetic effect. Thus, the 90-180 minutes range correctly captures the expected duration for mepivacaine in clinical practice.