My 2yo daughter has taken 4 Tums per day for the last few months to satisfy her calcium requirements. She was just yesterday switched from Prevacid to Axid, and there's a big label on the bottle (liquid) that says "Do not take with antacids" in bold letters. I just asked the pharmacist who filled it if that means don't take antacids at the same time as Axid or don't take antacids at all. He said it meant don't take antacids within two hours either side of the Axid dose. Do you agree? Wouldn't the warning label say something to that effect if it's just a time restriction and not a total restriction? Thanks.

Hi Lesley, this is a suspected interaction whereby the bioavailability of the axid (or zantac, or tegamet or pepcid) may be slightly reduced when given at the same time as the antacid. There are conflicting results from studies that try to test this theory and while the peak availability may be reduced, it doesn't seem to drop the peak plasma level below what is considered to be therapeutic. In any case, it is probably better to just separate the doses by a couple of hours (and yes you can still give the antacid - just separate it from the axid dose).
Thanks
Graham Ph.C.