Looks like it is a bit like slow release Tramadol which is also a synthetic opioid in the same family of drugs. My doctor has mentioned palexia as an option if I have to move on from tramadol which Ive been taking for years. I'm reluctant to up the ante at this stage so we are keeping it in reserve.
I'm not a big fan of the SRs, I find they leave me feeling a bit hung over and headachy as they wear off--not a problem with the standard version. It kicks in, then it stops.
For me, Tramadol works well to give me some relief from myalgia and joint aches as well as the misery of encapsulated implants -not pain free mind you, just bearable. I prefer to take one in the morning which Ive found allows me to get up and moving. It lasts about 4 hours. After that I've decided I've just got to live with the pain. Which is my excuse for being diabolically grumpy in the afternoon. The SR version really didn't agree with me but everyone is different. Good luck