gastrointestinal disorders
Medications for the Treatment of Gastric Acidity
Antacids
These agents neutralize gastric acid and reduce pepsin activity (which diminishes as gastric pH rises to>4.0). In addition, some antacids adsorb pepsin. Antacids may interfere with the absorption of other medications (eg,tetracycline,digoxin, iron). Antacids relieve symptoms, promote ulcer healing, and reduce recurrence. They are relatively inexpensive but must be taken 5 to 7 times/day. The optimal antacid regimen for ulcer healing seems to be 15 to 30 mL of liquid or 2 to 4 tablets 1 and 3 hours after each meal and at bedtime. The total daily dosage of antacids should provide 200 to 400 mEq of neutralizing capacity. However, antacids have been superseded by acid-suppressive therapy in the treatment of peptic ulcer and are used only for short-term symptom relief. In general, there are 2 types of antacids: Absorbable Nonabsorbable Absorbable antacids(eg,sodium bicarbonate,calcium carbonate) provide rapid, complete neutralization but may cause alkalosis and should be used only briefly (1 or 2 days). Nonabsorbable antacids(eg, aluminum ormagnesium hydroxide) have fewer systemic adverse effects and are preferred. Aluminum hydroxideis a relatively safe, commonly used antacid. With chronic use, phosphate depletion occasionally develops as a result of binding of phosphate by aluminum in the gastrointestinal tract. The risk of phosphate depletion increases in patients who have an alcohol use disorder, undernourished patients, and patients with renal disease (including those receiving hemodialysis).Aluminum hydroxidecauses constipation. Magnesium hydroxideis a more effective antacid than aluminum but may cause diarrhea. To limit diarrhea, many proprietary antacids combine magnesium and aluminum antacids. Because small amounts of magnesium are absorbed, magnesium preparations should be used with caution in patients with renal disease. 