178 DEPRESSANTS TO PERIPHERAL NERVES 



■whicli simply cuts off the nerve influences, tends to reduce the milk, 

 but cannot cause complete stoppage of it. The action is obtained 

 both from external application and internal administration. The 

 action upon the digestive glands and those of the respiratory system 

 has been mentioned previously. The lack of influence upon the kid- 

 neys is due to the fact that the secretion of these glands is not so 

 dependent upon nervous influences. 



Eye. Atropine causes dilatation of the pupil, with loss of re- 

 action to light, loss of power of accommodation and an increase in 

 intra ocular pressure, and lessens pain. The dilatation of the pupil 

 and loss of accommodation are due to paralysis of the endings of the 

 oculo motor nerves, while the increase in pressure usually accom- 

 . panics dilatation of the pupils, because this tends to shut off the 

 escape of fluid through the spaces of Fontana at the margin of the 

 pupil, into the canal of Schlemm. These effects are produced from 

 both the local application and general application of the drug. My- 

 driasis will be produced in about one-half hour after local applica- 

 tion of the drug, reach the maximum in % — 1 hour, and last for sev- 

 eral days. Loss of power of accommodation is not produced so 

 quickly and does not last so long. 



Pain. Atropine gives moderate relief from the pain of iritis 

 and other intraocular inflammations. 



With Homotropine the effect is secured more promptly, but is not 

 so persistent and consequently this drug is to be preferred for diag- 

 nostic purposes or for examination of the interior of the eye, while 

 atropine is to be recommended when it is desired to keep the pupil 

 dilated for a considerable period of time, as in iritis. 



Temperature. Therapeutic doses have no effect upon the 

 temperature, but large doses frequently raise temperature, prob- 

 ably on account of an increased circulation and oxygenation. Toxic 

 doses lower the temperature. 



Absorption and Elimination. Atropine is rapidly absorbed. 

 It is quickly eliminated by the kidneys, although some is oxidized by 

 the tissues. The greater part is eliminated by the kidneys unchanged. 



Urinary Organs. The action upon the amount of urine is un- 

 certain and unimportant: but in poisoning both suppression and re- 

 tention have been reported. Since the drug is largely excreted vm- 

 changed, the urine is a dilute solution of it, and atropine will exert 

 a remote local action in the urinary tract and lessen pain and spasm. 

 In cases of poisoning, the urine concentrated by boiling and applied 

 to the eye of an animal will dilate the pupil and hence may be 

 employed as a test for poisoning. 



Therapeutics. 



1. To relax spasm and over-contracted smooth m,uscle. Bella- 

 donna is of but little service in general convulsion or those of spinal 



