I have no experience with this, but did use the fetynal pain patch. With any transdermal dermal patch you have to careful in regards to discarding them, even after the use of it, which ingediants can still be active, harmfull, and may be obtained by pets, children, even adults, accidently, even by stepping on them. Somehow my translucent patch got stuck on my arm when discarding in the trash after putting on a new patch on my chest, meaning I received more dosage than I was usually taking. I then used the new backing to put on the old one, I could have even put in a jar like I do with my old insulin needles. I also put the date on the patch I put on. Glad your cat is ok, and you were able to get replacements. Good luck with the rest of your treatments.