Antacids (Oral)

Before Using This Medicine

If you are taking this medicine without a prescription, carefully read and follow any precautions on the label. For antacids, the following should be considered:

Allergies - Tell your health care professional if you have ever had any unusual or allergic reaction to aluminum-, calcium-, magnesium-, simethicone-, or sodium bicarbonate-containing medicines. Also, tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Diet - Make certain your health care professional knows if you are on a low-sodium diet. Some antacids contain large amounts of sodium.

Pregnancy - Studies on effects in pregnancy have not been done in either humans or animals. However, there have been reports of antacids causing side effects in babies whose mothers took antacids for a long time, especially in high doses during pregnancy. Also, sodium-containing medicines should be avoided if you tend to retain (keep) body water.

Breast-feeding - Some aluminum-, calcium-, or magnesium-containing antacids may pass into breast milk. However, these medicines have not been reported to cause problems in nursing babies.

Children - Antacids should not be given to young children (under 6 years of age) unless ordered by their doctor. Since children cannot usually describe their symptoms very well, a doctor should first check the child. The child may have a condition that needs other treatment. If so, antacids will not help and may even cause unwanted effects or make the condition worse. In addition, aluminum- or magnesium-containing medicines should not be given to premature or very young children because they may cause serious side effects, especially when given to children who have kidney disease or who are dehydrated.

Older adults - Aluminum-containing antacids should not be used by elderly persons with bone problems or with Alzheimer's disease. The aluminum may cause their condition to get worse.

Other medicines - Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking antacids, it is especially important that your health care professional know if you are taking any of the following:

• Cellulose sodium phosphate (e.g., Calcibind) - Calcium-containing antacids may decrease the effects of cellulose sodium phosphate; use with magnesium-containing antacids may prevent either medicine from working properly; antacids should not be taken within 1 hour of cellulose sodium phosphate

• Fluoroquinolones (medicine for infection) - Antacids may decrease the effects of these medicines

• Isoniazid taken by mouth (e.g., INH) - Aluminum-containing antacids may decrease the effects of isoniazid; isoniazid should be taken at least 1 hour before or after the antacid

• Ketoconazole (e.g., Nizoral) or
• Methenamine (e.g., Mandelamine) - Antacids may decrease the effects of ketoconazole or methenamine; these medicines should be taken 3 hours before the antacid

• Mecamylamine (e.g., Inversine) - Antacids may increase the effects and possibly the side effects of mecamylamine

• Sodium polystyrene sulfonate resin (SPSR) (e.g., Kayexalate) - This medicine may decrease the effects of antacids

• Tetracyclines (medicine for infection) taken by mouth - Use with antacids may decrease the effects of both medicines; antacids should not be taken within 3 to 4 hours of tetracyclines

Other medical problems - The presence of other medical problems may affect the use of antacids. Make sure you tell your doctor if you have any other medical problems, especially:

• Alzheimer's disease (for aluminum-containing antacids only) or
• Appendicitis (or signs of) or
• Bone fractures or
• Colitis or
• Constipation (severe and continuing) or
• Hemorrhoids or
• Intestinal blockage or
• Intestinal or rectal bleeding - Antacids may make these conditions worse

• Colostomy or
• Ileostomy or
• Inflamed bowel - Use of antacids may cause the body to retain (keep) water and electrolytes such as sodium and/or potassium

• Diarrhea (continuing) - Aluminum-containing antacids may cause the body to lose too much phosphorus; magnesium-containing antacids may make diarrhea worse

• Edema (swelling of feet or lower legs) or
• Heart disease or
• Liver disease or
• Toxemia of pregnancy - Use of sodium-containing antacids may cause the body to retain (keep) water

• Kidney disease - Antacids may cause higher blood levels of aluminum, calcium, or magnesium, which may increase the risk of serious side effects

• Sarcoidosis - Use of calcium-containing antacids may cause kidney problems or too much calcium in the blood

• Underactive parathyroid glands - Use with calcium-containing antacids may cause too much calcium in the blood