Aaah.......I thought that was just anti parasite, I'm an esha queen myself, seems to cure all when I have had problems, though I have never had a none eater to treat before.
I think if it were me I'd be trying hard to grow some nice green algae of some rocks and see if it will at least have a munch on that. At least it will give a clue as to whether it's an issue of acclimatisation and finding the right food to tempt him. You're little L144's Lisa just love mushroom, it's by far their favourite, they can see off a huge one in a day. It could just be trial and error assuming the meds don't work