4 THERAPEUTIC AGENTS DEFINED 



III. AGENTS WHICH ACT UPON ORGANISMS WHICH INFEST THE 



HUMAN BODY 



Antiseptics. 



Disinfectants. 



Antizymotics. 



Anthelmintics. 



Antiparasitics. 



Antiperiodics. 



THERAPEUTICAL AGENTS DEFINED 



HAEMATICS restore the quality of the blood to normal condition. They 

 exert a direct influence on the composition of the blood: e.g., preparations 

 of iron, of manganese, cod-liver oil, etc. 



ALKALIES act, in the concentrated form, as caustics (escharotics), but 

 when diluted, as antacids. Dilute alkalies, if given before meals, however, 

 will stimulate the production of the acid gastric juice. The carbonates 

 of potassa and soda and the bicarbonates, also preparations of the alka- 

 line earths, such as lime-water and mixtures of magnesium carbonate, are 

 good examples. Some of the salts of the alkalies have a remote antacid 

 effect, becoming decomposed in the blood and excreted in the urine, which 

 they render less acid. 



ACIDS. These have an action opposite to that of the alkalies. When 

 much diluted, they are administered for the purpose of checking hyper- 

 acidity of the stomach, by stimulating the production of the alkaline pan- 

 creatic juice and checking the acid gastric juice. Examples: Dilute hydro- 

 chloric acid, phosphoric acid. 



DIGESTANTS. Agents which effect solution (digestion) of food in the 

 alimentary canal. Examples: Pepsin, pancreatin, trypsin, papain, etc. 



ANTIPYRETICS. Agents which reduce the temperature of the body, 

 either by reducing the circulation or diminishing tissue change, or metabo- 

 lism, or favoring the loss of heat through radiation, conduction, etc. Ex- 

 amples: Quinine, aconite, antipyrine, antimony, etc. 



ALTERATIVES. A term used to designate a class of agents which alter 

 the course of morbid conditions, modifying the nutritive processes while 

 promoting waste, by stimulating secretion, absorption, and the elimination 

 of morbid deposits; especially used in the chronic diseases of the skin. 

 Employed in the treatment of phthisis, syphilis, gout, neuralgia, asthma, 

 etc. Examples: Arsenious acid, mercury, iodine and the iodides, sarsa- 

 parilla, guaiac, colchicum, stillingia, etc. 



CEREBRAL EXCITANTS. Agents which increase the functional activity 

 of the cerebrum, without causing any subsequent depression of brain 

 function. Examples: Camphor, valerian, caffeine, cannabis (in small 

 doses), etc. 



CEREBRAL DEPRESSANTS have an opposite effect to the preceding, 

 lessening brain activity. Some of the drugs of this class are employed 

 as hypnotics or as analgesics. 



