[Length of effectiveness of calcium-containing and calcium-free antacids. A double-blind study].

The effect of a Ca-containing and Ca-free antacid on meal-stimulated acid secretion was examined by intragastric titration with pH being measured extragastrically. The Ca-containing antacid was more effective in neutralisation of the intragastric content (pH greater than 5,8) and increasing the pH (p less than 0,002). The acid secretion was reduced (p less than 0,04) by the Ca-free antacid and remained constant after administration of the Ca-containing antacid. There were no significant differences between acid secretion before and after the administration of the Ca-free and the Ca-containing antacid.