CHAPTEE IX 

 ANTIPYRETICS OR FEBRIFUGES 



These are agents used to reduce the temperature of the body in 

 fever, but most of them will not reduce a normal temperature. The 

 constant temperature of warm blooded animals depends upon a proper 

 balance between heat production and heat dissipation. Heat is 

 largely produced in the muscles and glands, and is largely lost 

 through the lungs, feces, urine, etc. The normal balance is main- 

 tained by the heat regulating mechanism. 



The circulation is an important factor both in heat production 

 and heat loss, since the vessels of the skin not only form a cooling 

 apparatus for the dissipation of heat produced in other parts of the 

 body (radiation) but also lessen its production in the following man- 

 ner: When the vessels of the skin are dilated, the blood not only 

 flows through them much more quickly and is cooled, but being with- 

 drawn from the muscles and glands, their activity is reduced and 

 consequently less heat is produced. The opposite is also true when 

 the cutaneous vessels are contracted. Since the condition of the ves- 

 sels is regulated by the vasomotor center, drugs acting upon it may 

 greatly modify body temperature. 



This group known as antipyretics will include only those 

 drugs whose most prominent action is to reduce temperature in 

 fevers. It does not include aconite, digitalis, alcohol, camphor, etc., 

 which have the power to lessen fever, but have at the same time more 

 important actions which have led to their grouping elsewhere. 



For convenience of study, antipyretics may be divided into three 

 therapeutic groups: the quinine (or antimalarial group of human 

 medicine), the coal tar or analgesic, and the salicylates or anti- 

 rheumatic. 



CINCHONA 



Synonym. Peruvian Bark. 



Two varieties of Cinchona are official, Cinchona (yellow cin- 

 chona) and Cinchona Kubra (red cinchona). They are the dried 

 barks of certain species of cinchona yielding 5 per cent, of the 

 alkaloids of the respective variety. The fluidextract and tincture 

 are made from cinchona and the compound tincture from the red 

 variety. 



Active Principles. Cinchona contains some eighteen or nine- 

 teen alkaloids, the four principal ones being quinine, quinidine, cin- 



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