328 VEGETABLE DRUGS ^ 



There is also great excess of secretion which may result in a drowning 

 process. A poisoned animal is drowned in its own secretion. The res- 

 piration becomes weak and slow and death occurs from asphyxia after 

 lethal doses. 



Nervous System and Muscles. — Medicinal doses do not cause any 

 functional disturbance of the nervous system^ but very large doses excite 

 the spinal motor tract and reflex centres and cause convulsions in frogs, 

 succeeded by spinal depression and paralysis. The latter is due in part 

 to an influence on the muscles themselves. Tremors occur occasionally 

 in man and the domestic animals in poisoning. The sensory nerves escape 

 unscathed. The involuntary muscles are stimulated throughout the body, 

 owing to the direct action of the drug upon their motor nerve terminations. 



Skin. — Moderate doses of pilocarpine stimulate but slightly the 

 secretion of sweat in the lower animals, but in man the secretion is enor- 

 mous (1 qt. to 1 gal.). The salivary secretion appears to supplant that 

 of the skin in the domestic animals, unless very large doses are employed 

 (H., gr.vii-xii), which cause diarrhea, salivation and loss of body weight 

 (40 to 60 lbs.), and may entail pulmonary edema and heart failure. In 

 the horse, after a therapeutic dose of pilocarpine is given under the skin, 

 salivation occurs within 10 minutes and may last 2 hours, but the skin 

 is only slightly moist — if at all. The secretory nerve terminations are 

 stimulated. The secretions of tears, nasal mucus and milk are slightly 

 increased in the same manner, and the growth of hair is rendered more 

 luxurious. 



Temperature. — The temperature is reduced by evaporation from the 

 skin, if there is much sweating. 



Genito-Urinary Organs. — Pilocarpine exerts a slight and uncertain 

 oxytocic action on the pregnant uterus and has sometimes precipitated 

 parturition in pregnant animals at full term. The unstriped muscle of 

 the spleen and bladder is stimulated, and micturition is frequent. Pilo- 

 carpine, in repeated small doses, augments the flow of urine and prob- 

 ably increases tissue waste and the excretion of urea by its general 

 action on the secretions. It is eliminated unchanged by the urine. 



Eye. — Pilocarpine contracts the pupil when applied to the eye; it 

 also reduces tension of the eyeball and induces contraction of the ciliary 

 muscle. The myosis is due to stimulation of the peripheral oculomotor 

 nerve endings. When the alkaloid is given internally it may contract the 

 pupil, but jaborandi, or the fluid extract, is less likely to do so on 

 account of the opposing alkaloid (jaborine), which tends to dilate the 

 pupil. 



Summary. — Pilocarpine possesses two important actions. 1. To i»- 

 crease secretions (stomach, pancreas, intestines, salivary glands, sudo- 

 riparous, lachrymal and mammary glands, kidneys, bronchial and nasal 

 mucous membranes, and ear). 2. To stimulate the involuntary muscles 

 (stomach, intestines, heart, bronchial tubes, uterus, bladder, spleen, ves- 

 sels and iris). Both actions are peripheral and are exerted on the secre- 

 tory and motor nerve terminations. 



Administration. — Pilocarpine is given usually when an immediate 



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