Aluminum-based antacids (such as Amphojel) are less potent and work more slowly than other products do. They may also cause constipation. Some may cause calcium loss and should not be taken by women who are past menopause. If you have kidney problems, check with your doctor before you use aluminum-based antacids.
Combination aluminum-magnesium antacids are less likely to cause constipation or diarrhea than are aluminum-only or magnesium-only antacids. Examples include Maalox, Mylanta, and Riopan. Many of these types of antacids contain simethicone to help break down gas bubbles in your stomach.
Antacids with alginic acid (such as Gaviscon) contain a foaming agent that floats on top of the stomach contents. This may help keep stomach juices from coming in contact with your esophagus.