An antacid is a base that neutralizes this excess acid. This excess acid is what could be causing the ulcer or making it worse and preventing healing. So we neutralize the acid with an antacid so the ulcer is no longer being irritated and can heal. It provides almost instant symptomatic relief. It promotes healing of the ulcer which unfortunately takes 6-8 weeks.
The goal of an antacid is to buffer the stomach pH so it is between 4-5, which is still very acidic but the stomach pH is normally 1-2. We don’t make the stomach be completely neutral (pH of 7) because that will cause a reaction called rebound acidity where the stomach will put out more acid than usual.
We administer antacids at times when we are going to have the most amount of acid: Usually 1 hour after a meal and 3 hours after a meal. We don’t have slow release antacids so we can’t control what happens to the pH at night (short of taking antacids in the middle of the night), which causes our therapy to fail.
- Neutralizes excess acid that causes ulcerations
- Provides symptomatic relief
- Promotes healing of ulcers
- Goal: Buffer stomach pH between 4 and 5
- Exceeding pH of 5 leads to rebound acidity
- Administration time: 1 and 3 hours post meal
Sodium Bicarbonate (Rolaids): This is our best neutralizing antacid but it has a lot of sodium. Our problem with it is that it may be “too good” making the pH exceed 5 and we risk rebound acidity.
Aluminum Hydroxide (Alternagel, Amphojel): weak antacid but it’s constipating.
Magnesium Hydroxide: good antacid but it causes diarrhea.
So how do we get around this problem of one causing constipation and the other causing diarrhea? We combine them! And this is known as Maalox or Mylanta as it’s both Magnesium Hydroxide and Aluminum Hydroxide mixed together.
Tums also falls under antacids. It’s calcium carbonate (instead of sodium carbonate) and not as strong as these others. When we’re dealing with tums, it’s usually just to provide relief from stomach upset. The calcium in calcium carbonate is also not very well absorbed and it must be taken with other foods. Some people even take it for the calcium itself.