My grandson is taking Terbinafine for toenail fungas, I noticed about a week into his treatment that his attitude changed. I thought he was just being a teenager but I have spoke to one of his teachers at school and while he knows and understands his work, he sits in class and doesn t get it finished and doesn t turn it in as well as testing poorly recently on a couple of tests he shouldn t of had any problem with. I am hoping its just him and not the medication.