are you on any other meds? When I went to get a scrpit filled for some anti-nausea tablets (Maxalon) the pharmacist said that I shouldn't be taking them with one of my psych meds. I was on several at the time so can't remember which one it specifically reacted to, but it made sense given the severe side affects that I had...
Just a thought as to why you might have reacted to it...or could you be going into labour?!?! (vomitting was my 1st 'sign' of labour lol)