Hi i feel I should write my experience with matrifen patch and Tizanidine a muscle relaxant. I was on matrifen for nearly a year before I started having sleeping problems ended up sleeping alot during the day and waking up and going to the loo at night.
Finally 3 years later i saw a sleep doc and had an overnight sleep study and found out I had central sleep apnea where your brain doesnt make an effort to breath while asleep so came off matrifen patch(fentanyl) and it had gone.
But because I had been put on tizanidine in the mean time I still had sleep probs but because sleep studies came up normal. I did not know it was tizanidine at the time because of course I had been taking matrifen at the same time. But two years later I was getting fed up with sleep probs plus hallucinations as well and decided to try coming off it After asking Drs. I completely came off it and dont have sleep probs or hallucinations now.
Sorry for it being such a long post.