I also face the issues with stage 4 CKD and medications for pain for low back pain. I refuse to take the injections as usually I have to travel alone. My kidney doctor says you can take up to 1200 mg daily of gabapentin but I have been on it so long that it no longer works. I have resorted to CBD gummies which help but are costly. My medication list is so long due to other diseases and just trying to keep progression slowed that to add even one more medication would send me over the edge. I also am facing dialysis later this year and personally decided that being pain free and living with dialysis is better for me than living with pain. At this point and time, I am looking for quality of life over quantity of life. Many patients can live for years on dialysis. I also have exercises which can be done safely in a chair or stretches that is done laying flat on the floor (I have to have someone help me up after though). Right now, with 8 physicians for multiple issues our goal is to keep my eyesight, reduce my pain, and work for a quality of life. So far, my eyesight is the only thing we have managed to save as you just keep treating symptoms and the list of medications to have to monitor and keep track of is so time consuming that your quality of life is messed up anyway.
I hope you find something that works for you but like I said, I found that CBD gummies and warm tea seems to be better than any other drug they allow.