(3) Speed of action. It is desirable that an antacid product act quickly once
it has been ingested.
Other side effects specific to individual agents.
a. Sodium Bicarbonate (NaHCO3). Sodium bicarbonate is used as a gastric
antacid, urinary alkalizing agent, and an agent used to counteract the lowering of the pH
of the blood in heart failure (raising the pH of the blood during heart failure increases the
pharmacological effectiveness of epinephrine). The usual dosage of sodium
bicarbonate is 0.3 to 2 grams as needed. Side effects associated with this agent
include systemic alkalization (raising the pH of the blood) and acid rebound. The
patient receiving sodium bicarbonate for antacid purposes should be told that it should
not be used frequently and that it should not be used for prolonged periods. Sodium
bicarbonate is available in tablets of various strengths and in powder form.
b. Calcium Carbonate and Glycine (Titralac). Titralac is used as a gastric
antacid. The usual dosage of this product is from one to four tablets or from one to four
teaspoonsful four times daily. Side effects associated with this product include acid
rebound and systemic alkalization. The patient receiving this product should be
cautioned not to use it for prolonged periods. Persons receiving the tablets should be
told to chew them thoroughly before swallowing them. Patients receiving the
suspension should be told to shake the preparation well before taking the medication.
Titralac is available in both suspension form (1 gram calcium carbonate and 300
milligrams of glycine per 5 milliliters) and tablet form (300 milligram tablets and 600
c. Magnesium Hydroxide (Milk of Magnesia). Magnesium hydroxide is used
both as an antacid and as a cathartic (laxative). The antacid dose of milk of magnesia
(MOM) is one to two teaspoonsful as needed. The cathartic dose of MOM for adults is
one to two tablespoonsful taken with one or more glasses of water. Patients taking this
product should be cautioned that they can obtain the laxative effect if they take too large
a dose or if they take the antacid dose too often. A side effect associated with MOM is
diarrhea. Patients who receive MOM in suspension form should be told to shake the
suspension thoroughly, while patients taking the tablet form of the product should be
cautioned to chew the tablets thoroughly.