Slick, Yes, unfortunately most pain meds will affect the kidneys in cats. This is one reason why I'll be using a pain patch or buprenex on my Sunny. I hope that the extra litter boxes will help. You might also want to try buying some puppy pee pads and putting some of these down. I hope that you're able to find all of the pee spots and clean them up well. You can Max continue to remain in my thoughts and prayers. Please take care. (((HUGS)))