Antacids can help neutralize stomach acids, which can cut that burning sensation you feel when you have an empty stomach. Antacids are very effective in soothing stomachs, but they can have side effects. For example, magnesium-based antacids can cause diarrhea, while calcium-based antacids can cause constipation. Antacids with aluminum hydroxide can also cause constipation.
The dose in an antacid tablet is lower than in liquid preparations and therefore may be less likely to contribute to secondary problems.