I have been prescribed Voltaren but my Doctor was reluctant to give it to me due to the side effect of changing kidney function. I have extreme back pain due to an injury and surgery several years ago. I also had a valve replacement and after that it was complicated with renal failure. My kidneys did come good. I have just had blood tests and my Dr has just called me to tell me that I must stop the Voltaren immediately as it is interfering with kidney function. Is there anything I can take to help the pain?