Fentanyl patches are most definitely a thing, but they aren't given out much anymore, AFAIK. People do use them recreationally, but normally by chewing on small bits of the patch or smoking it somehow. It is super dangerous and I have heard of many people ODing that way, because the patches have time released dosages on them.

I knew a kid in high school that had stomach cancer and was prescribed fentanyl patches. He would trade the patches to junkies for weed, because he hated them. This was before medical marijuana so doctors were still throwing out opiates at everything.

I think that you are right that the patches are less potent when used correctly, but addicts aren't doing that when they get their hands on them. I think they have definitely cut down on giving them out nowadays, though.