Reasoning with a demented person won't work. So you'll have to figure out another way. Can you hire a cook? Or a caregiver that can slip meds into snacks? Can you lie, and tell her that the Exelon patch is to keep her skin beautiful?
You might find some useful ideas here:
http://alzlibrary.wordpress.com/2009/07 ... -medicine/
And you might find some useful ideas from the short article on anosognosia from this post:
Finally, you can do a search of past posts on the topic of "refusing to take medication" as this has come up before and there may be good ideas raised by others in the past.