I have been taking Vicodin for many years for back problems/injury/surgery but stopped working after a while, due to tolerance. So my Dr. started me on Oxycodone which helped but I had severe itching and other bad side effects. My pain was so bad that she put me on Hydromorphone. It has not helped yet. I tried the minimum dose first and worked my way all the way up to the maximum dose my Dr. said I could take which is 12mg (not controlled or extended release) and all it does is give me a head ache and make me tired. Is this usual. Every person I have known or read about that has taken this, has always said things like"Oh it;s the miracle drug"or"This is the best pain reliever out there"or"Wow I feel like I'm in heaven instead of in pain"why do I have a head ache and won't it work?