PART IV. PHARMACOLOGY. 



STRYCHNINE. 



Strychnine (C2iH22N2O2 = 331-73) is an alkaloid derived from the dried ripe 

 seed of Strychnos Nux Vomica, a tree indigenous to southeastern Asia. 



Pharmacodynamics. 



Central Nervous System. Strychnine remarkably heightens synaptic conductiv- 

 ity in the anterior columns of the spinal cord, extending motor response and disrupt- 

 ing normal co-ordinating influences. It also greatly intensifies sensory irritability. 

 It increases cerebral reflexes, especially those of the special senses. 



Muscular System. Strychnine has no direct action on voluntary muscle, but in- 

 directly stimulates involuntary muscle. 



Respiration. Strychnine slightly quickens and deepens respiration, when admin- 

 istered in small doses. Poisonous doses produce asphyxia by spasm of the respiratory 

 muscles. 



Heart is not affected directly. 



Blood-pressure. Strychnine stimulates the vasomotor centers, raising slightly the 

 blood-pressure through constrictor action in the splanchnic area, which is not offset 

 by the peripheral dilatation. 



Alimentary Tract.- Strychnine stimulates the flow of saliva. 



Metabolism. Oxidation is augmented by strychnine. 



Temperature is slightly increased from the advanced oxidation. 



Absorption takes place rapidly from the alimentary tract and from the subcuta- 

 neous tissues. 



Excretion is mainly via kidneys, and is much prolonged (2 to 8 clays), though the 

 greater part is eliminated in a few hours. 



Tolerance is not acquirable; in fact, susceptibility to strychnine action seems to 

 increase with its use. 



Symptoms. 



Therapeutic Doses. Poisonous Doses. 



Improved appetite. Tense muscles of face and neck. 



Cheerfulness. Heightened reflex irritability. 



Accentuated color-sense. Restlessness. 



Extended field of vision. Involuntary tremors. 



Sharpened sense of hearing. Convulsive movements. 



More delicate tactility. Risus sardonicus. 



Facial cyanosis. 



Opisthotonus. 



Asphyxia and exhaustion. 

 Therapeutics. 



The principal indication for Strychnine is as a stimulant for the central nervous 

 system. 



Dosage. 



Strychnina, 0.0006 to 0.002 Gm. 

 Strychnine Sulphas, 0.0006 to 0.002 Gm. 

 Tinctura Nucis Vomicse, 0.3 to 1.2 mil. 



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