Popular brands of antacids are Alka-Seltzer, Tums, Phillips’ Milk of Magnesia, Mylanta and Gaviscon, according to MedlinePlus. They all work well but have different ingredients that cause different side effects. Although tablets are more convenient, liquid forms work faster.
Alka-Seltzer is a sodium bicarbonate antacid that contains baking soda, according to WebMD. People with high blood pressure or who are on a salt-restricted diet should avoid it. Tums contains calcium, so it may cause constipation, but it can also be used as a calcium supplement. Phillips' Milk of Magnesia contains magnesium and may cause diarrhea; it is a laxative that is also used for constipation relief. Mylanta contains aluminum and magnesium, so it is less likely to cause constipation than aluminum-only or magnesium-only brands.
Gaviscon contains alginic acid. It creates a foam between acid and the esophagus. This is a different mechanism than in most antacids that work by changing the acid. This is a good choice for those with no damage to the esophagus, according to MedicineNet.com.
All these antacids should be used short-term. See a doctor if persistent heartburn or heartburn that does not get better with antacids is present. These could be symptoms of appendicitis, a stomach ulcer, gallstones or bowel problems.