Patients considering the use of antacids should inform the physician of certain medical conditions, such as a history of allergies to medicines containing aluminum, calcium, magnesium, simethicone or sodium bicarbonate. Allergies to other substances substances (e.g., foods, preservatives, dyes) should also be reported.

Many antacids contain high levels of sodium (salt) and may cause patients to retain water. Patients should inform their physician if they are on low-sodium diets. In addition, patients who have had a colostomy (surgery that creates an opening from the colon to the surface of the body) or ileostomy (surgery that creates an opening from the ileum to the surface of the body) or a history of inflamed bowel may be at risk for retaining fluid and electrolytes such as sodium or potassium. Patients with edema (swelling of the hands, feet or lower legs), heart disease, liver disease or toxemia related to pregnancy may find that antacids with sodium cause the body to retain too much water.

Patients with kidney disease may find that use of antacids raises blood levels of aluminum, calcium and magnesium. This can increase the risk of side effects associated with antacids. People with sarcoidosis (disease marked by the formation of nodules in the lymph nodes, lungs, bones and skin) who use antacids that contain calcium may experience kidney problems or excessive levels of calcium in the blood (hypercalcemia). Patients with parathyroid disease may find that using antacids that contain calcium also leads to abnormal levels of calcium in the blood.

Antacids may also make several conditions worse, including:

• Colitis
• Constipation
• Hemorrhoids
• Intestinal blockage or intestinal or rectal bleeding
• Alzheimer’s disease (only antacids containing aluminum)
• Bone fractures