308 VEGETABLE DRUGS 



into the external jugular vein, and that it safely may be given in this 

 manner in a dose of 3 grains dissolved in 30 minims of water, to horses 

 in fair condition and of average weight. 



The toxic line is too closely approached, however, when physostig- 

 mine" is used in this way, and we should be careful not to cross it by 

 extending the dose. Arecoline hydrobromide acts as rapidly and with- 

 out the unpleasant accompaniments of purgation caused by eserine, so 

 that the former is generally preferable as a cathartic for use by the 

 intravenous method. According to Quitman eserine given subcutaneously 

 in divided doses (gr.l^ every 20-30 minutes to effect) is far more effective 

 in emptying the bowels than arecoline given in this manner. Seldom 

 more than One and one-half grains are required and in doses of this size 

 it is safe even for aged animals. 



The minimum fatal dose of physostigmine is stated to be from gr. 

 1/15-1/12 for dogs, and gr. 1/30-1/20 for cats. The treatment should 

 be pursued with emetics, or the stomach tube, and the antidote, 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 de- 

 presses 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 peri- 

 pheral vagi in the heart, and so hasten a fatal result. Strychnine is 

 antagonistic to eserine in stimulating the respiratory centres and inferior 

 cornua. 



Uses External. — Physostigmine has been injected empirically, but it 

 is asserted with good results, into chronic dropsical effusions of joints 

 and bursae of tendons in horses, after removal of the fluid by aspiration. 

 From .05-.1 Gm. is used, dissolved in 5-10 Gm. of sterile water; and this 

 treatment is followed by cold applications for several days afterwards. 



Uses Internal. — Three physiologic actions of eserine are put to thera- 

 peutic uses. 



1 . The myotic action on the eye. 



2. Stimulation of the involuntary muscles. 



3. Depression of the inferior cornua. 



1. Eserine is useful, in alternation with atropine, to break up 

 adhesions to the iris ; to lessen intraocular tension in glaucoma ; and to 

 prevent prola_pse of the iris and staphyloma, after wounds and ulcers of 

 the cornea. It is also employed to contract the pupil and shut out the 

 light in photophobia, and to antagonize the influence of atropine on the 

 eye. The action of eserine is, however, not nearly so powerful or per- 

 sistent as that of atropine on the eye, and is somewhat painful. It is 

 employed in 1 per cent, solution. 



2. Physostigmine is mainly of value for its action in rapidly stimu- 



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