"i have multiple hernias in my low back and neck. my doctor abruptly stopped my vicodin because i had used it long term and was losing the effect of pain relief. started ultram 400mg a day. no withdrawal symptoms from vicodin. my pain level though didn&#039;t improve from the vicodin. i still feel the same as i did as the last few months of vicodin use. i have had bad withdrawal symptoms in the past from fentanyl and am a little worried about having to come off ultram someday as it appears to be hard to come off of. so basically it works like weak vicodin for me and i have had some erectile dysfunction symptoms as well. i saw someone else comment on that. i&#039;m young and never had any type of problems. i also take lyrica 150mg three times a day."