Comparison of New and Old Over-the-Counter Remedies for Gastric Acid

Now that histamine blockers are available over the counter at non-prescription strength, people must often choose between these newer agents and older antacids. This randomized, double-blind, placebo-controlled trial compared famotidine (Pepcid AC, 10 mg), calcium carbonate antacid tablets (Tums, 1000 mg), and placebo in 18 healthy volunteers.

The subjects were given two meals at 2.5 and 6 hours after taking the medications, while intragastric pH was maintained at 4.0 through an infusion of sodium bicarbonate. The amount of sodium bicarbonate required to maintain this pH was used to assess the effectiveness of the therapy.

Both famotidine and calcium carbonate lowered the need for sodium bicarbonate by about the same amount, but with differen…