Faithful Mumma, its a 'newer' drug and is still a catergory B1 drug (from memory), I had to really push to get it from a local GP. It comes in wafer form so you put it under your tongue and it dissolves, great cause if I was putting a tablet in mouth my mouth it sent me back down the toilet!
It name is Zofran Zydis Wafers (ondansetron). I was finally given that as I went slightly loppy and somewhat paraletic on Maxalon. If maxalon doesnt help you then this might be your answer. HTH