You can take Zantac, which is ranitidine and Zegrid, which is a proton pump inhibitor with an antacid, together. I take rantidine and a PPI and an antacid practically every day.
If I take Zantac, it makes me a bit constipated.
Don't take pepto with your drugs. Wait at least half an hour. This is because the pepto can stop your stomach from absorbing the drugs.
I hope this helps.