DRUGS ACTING ON THE DIGESTIVE ORGANS 25 



from the blood the salt should be given in concentrated solution, but 

 when a speedy purgative action only is required the saline should be 

 administered in considerable dilution. Concentrated or hypertonic saline 

 solutions cause copious transudation and secretion in the stomach so that 

 they become almost isotonic with the body fluids before leaving the viscus. 

 They irritate the stomach and retard its motor functions. Saline purga- 

 tives do not expel feces as well as others because they do not stimulate 

 peristalsis as much and leave much of the solids behind while mostly 

 liquid escapes. If absorbed they pass out by the kidneys and are 

 diuretic. 



The drastics included in this class of purgatives have the power of 

 markedly increasing intestinal secretion as well as peristaltic action. 



5. Cholaigogue Purgatives. — Cholagogues are agents which assist in 

 removing bile from the body. Some cholagogues are not generally con- 

 sidered purgatives, but it is proper to classify all of them thus, since 

 bile stimulates peristalsis. 



SUPPOSEDLY DIRECT CHOLAGOGUES. 



*Sodium salicylate *Sodium phosphate 



*Podophyllum Ipecac 



Aloes Euonymus 



Rhubarb *Nitro-hydrochloric acid 



Colchicum Corrosive sublimate 

 Sodium sulphate 



INDIRECT CHOLAGOGUES. 



Calomel 

 Mercury 

 Most purgatives in a less degree. 



The drugs marked with an asterisk have been found by clinical evi- 

 dence most active. 



The bile occurring at any time within the bowels is in part absorbed 

 and then re-secreted. This process may be repeated, indefinitely, but is 

 prevented by purgatives, especially those increasing peristalsis in the 

 duodenum and upper part of the jejunum (calomel), because they hurry 

 along and expel the bile in the gut before it has time to be absorbed. 



In this way calomel and purgatives are indirect cholagogues in re- 

 moving bile from the body; not by stimulating its secretion, but by 

 hastening its excretion from the bowels. The results of former experi- 

 menters have been swept aside by the more recent and thorough re- 

 searches of Stadelmann, on animals, and of Pfaff, on men, with biliary 

 fistulae. 



These researches show that there is no agent which has any marked 

 influence in increasing the secretion of bile, except bile itself. 



Salicylic acid and secretin do, however, have a feeble cholagogue 

 action. Moreover, there is no morbid condition in which increasing the 

 flow of bile would prove remedial. 



Clinically so-called cholagogues are, nevertheless, of value because 

 they act as purgatives (calomel), or as intestinal antiseptics (calomel. 



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