Zantac Duo Fusion™ Acid Reducer + Antacid. New! From the makers of Zantac®. Famotidine 10mg / calcium carbonate 800 mg. Magnesium hydroxide 165mg tablets. Dual action™. Just 1 tablet relieves heartburn due to acid indigestion. Cool mint. Chewable tablets. Use: Relieves heartburn associated with acid indigestion and sour stomach. Other information: Each tablet contains: Calcium 330mg; magnesium 70mg. Read the directions and warnings before use. Read the bottle label. It contains important information. All rights reserved. Questions Call 1-888-285-9159 (English/Spanish), M-F, 8:30 - 5 EST. © 2016, BI Pharmaceuticals, Inc.