GELSEMINE 42X 



Oelsemina^ Gelsemine. 

 (Non-official and uncertain in strength.) 

 Cose.— H., gr. \-i (.015-.03); D., gr.^-^ (.001-.003). 



Action External. — None. 



Action Internal. — Gelsemium exerts no action on the 

 digestive apparatus, or on tlie blood, after its absorption; 

 neither does it affect the circulation in medicinal doses, but 

 in toxic quantities it directly depresses the heart. The 

 influence of the drug on the vasomotor system is unknown. 



Nervous System and Muscles. — The prominent effect of 

 gelsemium is directed on the nervous system, as evidenced 

 by paralysis and convulsions after large doses. Both the 

 convulsant and paralyzant action are of spinal origin. That 

 the convulsions are not cerebral is shown by the fact that 

 they occur below the point of section in mammals (under 

 the influence of the drug), with divided spinal cord. That 

 they are not peripheral is proved by their occurrence in the 

 hind extremities when the posterior aorta is tied before the 

 animal is poisoned. The paralyzant action of gelsemium is 

 due to direct depression of the cells of the inferior cornua, 

 and this is followed, in the later stages of poisoning, by 

 depression of the motor nerve endings and spinal sensory 

 tract, with general anaesthesia. 



The cause of the secondary convulsions is undeter- 

 mined. A tetanizing principle in gelsemium, antagonistic to 

 gelsemine, such as we find in physostigma, has been thought 

 to be the cause of the convulsions. The muscles, motor 

 (except those of the face) and sensory nerves are unaffected 

 by gelsemium. 



Respiration. — Gelsemium, in toxic doses, progressively 

 weakens and paralyzes the medullary and spinal respiratory 

 centres, and death occurs from asphyxia. 



Eye. — In poisoning, in animals, there is dilatation of the 

 pupil produced in the latest stages of the toxic period. In 

 man, there is, in addition to this, paralysis and drooping of 

 the eyelids (ptosis), and paralysis of the recti muscles with 



Digitized by Microsoft® 



