18 GENERAL ACTIONS OF DRUGS 



the cause of tympanites, the antacids are conjoined to advan- 

 tage with carminatives (sodium bicarbonate and ginger). 

 The alkaline carbonates allay pain by means of the carbonic 

 dioxide set free in their decomposition in the digestive tract, 

 and the antacids are also beneficial in dissolving an exces- 

 sive secretion of mucus in catarrhal conditions of the alimen- 

 tary canal. 



The antacids are synonymous with alkalies, with the 

 exception of the neutral vegetable salts — acetates, citrates 

 and tartrates — of potassium and sodium, which are some- 

 times classed under this head. These do not alkalize the 

 contents of the stomach, but nevertheless are broken up in 

 the body and transformed into carbonates and thus render 

 the urine more alkaline during their elimination. Among 

 those included in the following list the sodium compounds 

 are much less active in alkalizing the urine than the potas- 

 sium salts. Sodium bicarbonate is in most fieqnent use in 

 digestive disorders, but ammonium carbonate is particularly 

 appropriate in flatulence, because it possesses the added 

 power of stimulating peristaltic action and expelling flatus. 



ANTACIDS. 



Sodium carbonate Ammonium carbonate 



Sodium bicarbonate Magnesia 



Potassium carbonate Magnesium carbonate 



Potassium bicarbonate Calcium carbonate (chalk) 



Solution of potash Solution of lime (lime water) 



Ammonia 



Acids. — The mineral acids — together with stomachics — 

 increase the vascularity and movements of the stomach. 

 The natural hydrochloric acid of the gastric juice assists in 

 the conversion of proteids (in the food) into peptones, and 

 is, therefore, the acid of most use in relation to stomach 

 digestion. It should be given one-half to two hours after 

 feeding animals, and it not only supplies any abnormal defi- 

 ciency of the natural acid secretion, but also stimulates the 

 formation of pepsin from pepsinogen, and the normal pro- 

 duction of this acid in the stomach. 



