4G GENERAL ACTION OF DRUGS 



act through influencing the colloid chemistry of the renal cells. Produc- 

 tion of acid in the renal cells leads to their swelling, edema and lack of 

 function. All salts, glucose and alkalies antagonize this condition, reduce 

 edema of the renal cells, allow water to pass through them, and are all 

 diuretic. Acidosis and edema of the renal cells are brought about by 

 lack of oxygen — hence caffeine, digitalis and agents improving renal blood 

 supply are diuretics in supplying oxygen. Salts and sugar dehydrate 

 tissue; therefore, common salt, sucrose, glucose and lactose are diuretics 

 in abstracting water from the tissue and renal cells. 



f/ie*.— Diuretics are useful in removing toxins and waste solid mat- 

 ters in the blood resulting from disease or the imperfect oxidation of albu- 

 minoid substances. Their action depends on an extra ingestion of water. 

 In fevers the potassium salts are employed with spirit of nitrous ether, 

 alcohol and digitalis. They are antipyretics by eliminating pyrogenic 

 material. Tissue waste is increased by diuretics, and they are serviceable 

 in plethora, rheumatism and obesity. In acute disease of the kidneys, 

 salines and digitalis are indicated; in chronic renal disorders salines and 

 diuretin (expensive) are often used. Diuretics remove water from the 

 system. They are, therefore, employed in edema and dropsy of renal or 

 cardiac origin (digitalis), and in chronic effusions, as in pleuritis and 

 pericarditis. In cases with edema water must, however, be restricted and 

 a salt-free diet given. Diuretics lessen irritation of the kidneys by 

 diluting the urine when the secretion is concentrated or contains toxins' 

 or other irritants (uric acid, calcium oxalate, etc.).. Finally, stimulating 

 diuretics (buchu, turpentine, etc.), are indicated in chronic inflammatory 

 diseases of the kidneys and bladder, and in relaxed and paretic disorders 

 of the bladder (incontinence of urine) to excite the reflex and motor 

 functions of the sphincter and detrusor muscles. ^ 



Drugs Influencing the Reaction of Urine. 



In man and animals secreting an acid urine, the basic phosphates of 

 sodium and potassium in the blood are decomposed by the renal cells, 

 and acid phosphates of sodium or potassium — ^being more diffusible — are 

 eliminated, giving the urine its characteristic reaction, while the bases 

 remain behind. In the case of the herbivora the urine is alkaline, because 

 there are larger quantities of magnesium and calcium salts in the food, 

 which precipitate phosphoric acid in the stomach, and because there is an 

 excess of alkaline sodium and potassium salts in the blood. The urine 

 may best be madei acid by' benzoic acid, which is converted into hippurie 

 acid during its passage through the kidneys. Salicylic acid, urotropin, the 

 mineral acids (as acid salts), and large quantities of the vegetable acids 

 and boric acid tend to acidify the urine in a less degree. An acid urine 

 may be made alkaline by alkalies, as salts of potassium, lithium, sodium 

 and calcium, together with the vegetable salts, tartrates, citrates and 

 acetates, which circulate as carbonates in the blood. Drugs promoting 

 diuresis make the urine less acid because the basic sodium phosphate in 

 the blood is not so readily broken up in the kidney when it diffuses 

 through the cells in great dilution. Ammonia fails to make the urine 

 alkaline because it is transformed into urea. 



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