Alka-Seltzer is a common antacid used to relieve an upset stomach ... The carbon dioxide forms when two key ingredients in these tablets, citric acid and baking soda (sodium bicarbonate), dissolve in ...

Even some antacids - such as Alka-Seltzer -- contain aspirin ... and vitamins. "Bring a list of all the medicines and supplements you take to your doctor," says Nieca Goldberg, MD, a spokesman ...