i had a lidocaine infusion about....... 4 years ago... so i don't remember the specifics... but it lasted about 2-3 hours and i remember feeling very sleepy. the relief lasted i think for about 2-3 weeks. i was then placed on a medication that worked in the same way as the lidocaine infusion. the infusion was used more as an indicator test to see if the particular med would help me. sorry but i don't remember what that med was... if i can think of it i'll let u know