PHYSOSTIGMINE 417 



former mode of administration is employed than after the 

 latter. Moreover, the disagreeable accompaniments of 

 purging last twice as long (five hours) after the hypodermic 

 method than after the intravenous injection (two and a half 

 hours). Muir deduces from his experiments that physos- 

 tigmine is a safe and active cathartic for the horse and is 

 free from evil after-effects; that along with increased peris- 

 talsis and mucous evacuation from the bowels there are 

 colic and more rapid pulse-rate with muscular tremors and 

 weakness; that eserine acts more quickly and effectively 

 when injected into the external jugular vein, and that it 

 may be safely given in this manner in a dose of 3 grains 

 dissolved in 30 minims of water, to horses in fair con- 

 dition and of average weight. 



The toxic line is closely approached, however, when 

 physostigmine is used in this way, and we should be 

 careful not to cross it by exceeding the dose. Barium 

 chloride acts as rapidly and without the unpleasant accom- 

 paniments of purgation caused by eserine, so that the 

 former is generally preferable as a cathartic for use by the 

 intravenous method. 



The minimum fatal dose is stated to be from gy^.-rfTZ 

 for dogs, and gr.^-^ for cats. The. treatment should be 

 pursued with emetics, or the stomach pump, and the anti- 

 dote, atropine. The latter will prevent death in rabbits 

 when given five minutes after the administration of three 

 times a minimum fatal dose. Atropine should be given 

 under the skin, together with alcoholic stimulants, digitalis, 

 and ammonia by the mouth. Artificial respiration should 

 be practised and external heat applied. The essential action 

 of atropine in antagonizing eserine, consists in stimulation 

 of the respiratory centres, while it depresses the peripheral 

 cardiac vagi, and so, to a certain extent, counteracts the 

 primary influence of eserine on the heart. Large doses of 

 atropine may only exaggerate the secondary depression of 

 eserine upon the peripheral vagi in the heart, and so hasten 



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