Hi All, I take Zonisamide(Zonagran) and Phenytoin(Dilantin) and have thickened mucous down in the back of my throat.This started after I had a problem with the underside of my tongue going very red and the bottom of my mouth swelling.I had already been on both drugs for a while before this occurred, I have seen my G.P. she thinks I've had a virus. Any thoughts? Janet