CHAPTEE X 

 DRUGS AFFECTING CHIEFLY THE NERVOUS SYSTEM 



These agents may be classified as : 



1. Those acting upon the central nervous system. 



A. Tliose stimulating. 



B. Those depressing. 



2. Those acting upon the peripheral nervous system. 



A. Those stimulating. 



B. Those depressing. 



DRUGS ACTING UPON THE CENTRAL NERVOUS SYSTEM 

 A. STIMULANTS TO THE CENTRAL NERVOUS SYSTEM 



Those agents which stimulate the central nervous system are : 

 Caffeine, strychnine, atropine and cocaine. Caffeine and nux 

 vomica or strychnine are the most important. 



CAFFEINE GROUP 



Caffeine is an alkaloid obtained from the coffee plant, Coffea ara- 

 hica, or from damaged tea leaves, Thea sinensis. It is found in 

 plants in widely separated parts of the world and which have no close 

 botanical relationship. The Arabians and Egyptians used the 

 roasted seeds of Ooffea arahica; the Western Africans, the seeds of 

 kola nuts ; the natives of the Amazon region, guarana made by pound- 

 ing the seeds, Paullinia Cupana, into a paste and drying this by 

 heat ; the Chinese and Japanese fermented tea leaves. In Paraguay 

 and Uraguay, " mate " or Paraguay tea, the dried leaves and shoots 

 of a species of ilex or holly were used ; in ISTorth America, Appalach 

 tea ilex cassine. The Mexicans and West Indians made a beverage 

 from the fermented seeds of the chocolate plant which contain a 

 similar aO^aloid, theohromine. 



Tea contains about 1 — 4 per cent., coffee 0.6 — 2 per cent., kola 

 nuts 1 — 2 per cent.. Mate 1 — 3 per cent, and guarana 3 — 6 per cent. 

 That obtained from tea was formerly called theine. 



Preparations and Doses. 



Gaffeina, caffeine is a white powder. One gram dissolves in 16 

 mils of water and 66 mils of alcohol. 



Doses. H. gr. xv — xxx; 1. — 2. D. gr. j — ^vij ; 0.06 — 0.5. 



126 



