with some anti Bs,it is okay to take zantac like an hour before your anti B dose,but you would have to ask the pharmacist about this ans whether it would affect the absorbtion of the anti B you are on. i had to do this with cipro and this was okay with the pharm. one other thing you can do to avoid this completley is just to get an pennicillin shot at the docs office instead of the orals. i cannot tolerate alot of the anti Bs out there,they all feel like they are boring a hole thru my stomach with very severe burning like an ulcer? just horrible. so now,when i need an anti B for like strep or other infections,i always ask about the penn shot first and if we can take care of this with it. it is sooo much better than dealing with the stomach crap that some of us just have with anti Bs. zithromax is the only anti B i can take that doesn;t do this to my stomach. you could go back to your doc and ask about gettig the shot if you are just beginning the course too ya know? hope you feel better soon. FB