CAFFEINE Ig-r 



Caffeina Citrata, citrated caffeine is a mixture of caffeine and 

 citric acid. It gi^'es a clear syrupy solution with a small quantity of 

 water but caffeine precipitates on dilution, then redissolves on further 

 dilution. 



Doses. About twice those of caffeine. It is not suitable for 

 hypodermic administration. 



Caffema Citrata Effei-vescens, effervescent caffeine citrate is an 

 effervescent preparation. It is not used to any extent in veterinary 

 medicine. The doses would be about the same as for citrated caf- 

 feine. 



Caffeinw Sodio-Benzoata, Caffeine-Sodium-Benzoate is a mixture 

 of caffeine and sodium benzoate. It contains when dried to constant 

 weight not less than 46 nor more than 50 per cent, of anhydrous 

 caffeine, the remainder being sodium benzoate. It occurs as a white 

 odorless powder with a slightly bitter taste. One gram dissolves in 

 1.1 mils of water ; some caffeine separates on standing and in 30 mils 

 of alcohol. It may be used hypodermically. 



Doses. PI. oj — ijss; 4 — 10. D. gTS. jss — xxx; 0.1 — 2. 



Caffeinse. Sodio-Salicylas N. F. contains about 60 per cent, of 

 caffeine. The doses are the same as for the preceding salt. It may 

 also be used subcutaneously. 



Action, Digestive System. Caffeine slightly stimulates peris- 

 talsis, increases the appetite in man, is a mild chologogue and laxa- 

 tive but is not used for these actions. 



Circulatory System. The characteristic actions of therapeutic 

 doses of caifeine are to accelerate the heart, increase its force and 

 raise blood pressure. The increased rate and force are due to direct 

 action on the cardiac muscle, while the blood pressure is raised on 

 account of the increased efficiency of the heart and constriction of the 

 blood-vessels through stimulation of the vasomotor center. On the 

 other hand, in some cases the rate of the heart is diminished and 

 blood pressure lowered on account of a tendency to stimulate the in- 

 hibitory center in the medulla and dilatation of some of the peri- 

 pheral vessels through action upon the plain muscle of their walls. 

 After very large or toxic doses, the heart beats so rapidly that the 

 ventricles do not have time to fill, delirium cordis takes place and the 

 organ stops in diastole. 



Respiratory system. Caffeine stimulates the respiratory center 

 and increases both the number and depth of the respirations. 



Nervous System. Caffeine is a true central nervous stimulant. 

 In man the psychic functions are first stimulated, then the motor 

 area is excited as is shown by restlessness, excitement and increase of 

 movements. Finally the cord is stimulated as is shown by convul- 

 sions. The action upon the brain is shown in animals by increased 



