For a strong, yet gentle medicine that acts on contact to relieve heartburn, acid irritation, sour stomach, bloating and gas, try Mylanta Tonight. In each 10 mL dose there is 800 milligrams of calcium carbonate; 270 milligrams of magnesium hydroxide; and 80 milligrams of simethicone . Calcium-rich formula gives multi-symptom relief with its extra coating power. Honey chamomile flavor. Bottle contains 355 mL of smooth, creamy antacid liquid.