Bw
the main ingredient you have to stay clear from is aluminum. So as long as zantac has no aluminium in it- it should be fine. If not, give the OB or even a chemist a call to find out. I got some gavison from the chemist that didnt work at all, but as i said, the Rennies i got from the supermarket did, and it says on the packet that they are safe to use during pg!
I would be ringing your OB today and organising the script ASAP. Why put yourself through another nite of hell! Plus the longer you leave it, the more chance you can burn your throat- trust me that aint fun either!

take care and hang in there!!

odette