My boy cat Diego is on kitty prozac as well. But not what your kitty is on, something with some silly long name that starts with an F. I can never remember it, let alone pronounce it. He's on the highest dose he can have and is doing really, really well. He was attacking his sister kitty. After running the gamut of tests to ensure it was not a health issue I opted for this after the vet suggested maybe he be put down as there are lots of nicer kitties out there that could use a good home. I opted for the drugs cause I love my boy and I'm so glad I did now. I don't know if he will ever be able to get off of them but they've been a godsend for us these past couple of years.