20 GENERAL ACTION OF DRUGS 



erally employed refers to their effect in exciting peristaltic action^ and so 

 expelling gas from the stomach and bowels. The aromatics are consider- 

 ably more valuable for this purpose than the bitters. Carminatives also 

 prevent griping caused by many cathartics, aid digestion, and disguise 

 the taste of disagreeable drugs. Capsicum and ginger are most fre- 

 quently prescribed in veterinary practice. 



Digestives. — Pepsin is occasionally of benefit in the treatment of 

 dogs and young animals in case of enfeebled gastric digestion resulting 

 from acute diseases or other general causes. It should be administered 

 directly after eating, and is prescribed to advantage with hydrochloric 

 acid. As a general proposition it is inadvisable to give agents which 

 merely substitute an artificial for the natural digestion, except as a tem- 

 porary expedient. A wiser course consists in removing the cause of indi- 

 gestion by proper feeding or by enforcing abstinence from food, and in 

 the use of remedies calculated to strengthen the natural digestive func- 

 tions. 



Pancreatin may be given during, or immediately after, eating, and 

 will assist gastric digestion for some time before sufficient acid is se- 

 creted to destroy it. In fact, some authors (Hare) insist that this sub- 

 stance is more valuable in any case than pepsin in aiding stomach 

 digestion, although pancreatin is more commonly given several hours after 

 eating, to promote intestinal digestion. Papain is another agent which is 

 employed as an artificial digestive of vegetable origin. Its value is not 

 yet definitely determined. 



Antiseptics. — These agents are sometimes used to prevent or arrest 

 fermentation of food in the stomach and bowels. Since fermentation is 

 primarily due to indigestion, it is essential to remove the cause by diet 

 and other rational means rather than to combat the effects of indigestion. 

 Large doses of antiseptics hinder the digestive processes and may endan- 

 ger the life of the patient, so that it is impossible to attain perfect anti- 

 sepsis in the alimentary canal. 



Among the dr,ugs more commonly employed for their antiseptic 

 action on the contents of the digestive tract may be mentioned: 



Carbolic acid Bismuth subcarbonate 



Creosote Bismuth salicylate 



Creolin Bismuth subgallate 



Naphtol Sodium sulphite, bisulphite and 



Naphtalin hyposulphite 



Bismuth subnitrate Hydrogen dioxide 



Emetics are drugs which cause vomiting. The act of vomiting pro- 

 ceeds from irritation of the vomiting centre in the medulla, which is in 

 close proximity to the respiratory centre. This centre is either' acted 

 upon ' directly by drugs circulating in the blood, or reflexly by agents 

 stimulating sensory nerves in various parts of the body. Thus, irritation 

 of the sensory nerve-endings of the mouth, throat, gullet, lungs, heart, 

 stomach, bowels, biliary passages, peritoneum, uterus and kidneys, may 

 produce vomition. Vomiting is occasioned by simultaneous contraction 



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