Hi mum was put on Donepizil 5mg tablets starting from Monday. She is now feeling sick, dizzy with bad headaches. She really is not feeling well at all and barely eating. Does anyone know how long the side effects last? It is awful seeing her like this, I haven;t actually told her it could be one of her tablets though as she would refuse to take it and the consultant did say to try and stick with it until her body adjusts to it.