The best replacement for antacid is acid reducer.

The best alternatives to antacid are rated as following:
★★★★★  acid reducer
★★★  ppi
★★  tums
  acid reducers
  anti acid

Your alternative for antacid is not listed? Suggest!
Speaking about antacid, one probably shouldn't forget about alginic acid.

Other search terms related to antacid and their ratings are:

★★★★★ alginic acid
★★ z pack
You have in mind a companion for antacid and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of antacid in all years. Click on graph for more.
acid reducer