some antibiotics....and there are very few that have this effect, one is used to treat TB and one for long term acne use, but you will need to check.......affect the pill not because the make you sick, but because the speed up the rate that enzymes in the liver get rid of the hormones in the pill.
There will be a warning on the antio biotic leaftlet (the one that comes in the pack) if this is the case.
if yu vomit while taking the pill, for whatever reason, you should follow the inof on the leaflet about taking extra precautions