NUX VOMICA — STRYCHNINE 131 



ated motor response. Strychnine tetan.us should be conceived as 

 caused by the extensive spreading of reflexes on the application of 

 normal stimuli. This spreading is not normally present except 

 after the strongest stimuli. 



Medullary centers. The centers in the medulla are first stimu- 

 lated, then depressed and finally paralyzed. This paralysis may be 

 obscured for a short time by the convulsions, but shows in the inter-, 

 missions between the convulsions in the later stages of poisoning; 

 and is the usual cause of death, unless the animal dies during a 

 respiratory spasm from asphyxia. Those factors concerned in the 

 death of the animal usually fail in the following order: Eespira- 

 tory center, vasomotor center, vagus center and cardiac muscle. 



Respiratory System. The respiratory center is stimulated 

 both directly and indirectly by increased muscular efFort causing the 

 respirations to be quickened and deepened, while large or toxic doses 

 quickly exhaust the center. Death takes place from asphyxia, due 

 either to tetanic contraction of the respiratory muscles during a con- 

 vulsion, or to exhaustion of the center between the convulsions. 



Circulatory System. Medicinal doses raise blood pressure and 

 slightly slow the heart. The former is due to vasoconstriction by 

 stimulation of the vasomotor center and the latter, to stimulation of 

 the vagus center. Frequently no result is seen. There is no action 

 on the heart in therapeutic doses, probably not in toxic ones, and 

 strychnine is not a cardiac stimulant in the truest sense of the word. 

 Clinicians, however, quite generally assert that it is a cardiac stimu- 

 lant. This does not necessarily mean that it has any direct action 

 on the heart but that the pulse is improved. The improvement in 

 the condition of the pulse is probably due to an increased blood 

 pressure. Toxic doses at first cause a great increase in blood pres- 

 sure due to stimulation of the vasomotor center, but this stimulation 

 is followed by depression and the pressure falls. 



Special Senses. All the special senses appear more sensitive 

 under influence of strychnine. Vision, hearing, and sound seem to 

 be more acute. 



Muscle. The tone of all muscle is improved. There is no 

 direct action upon muscle, but there may be increased muscular, 

 power, resulting from an increased reflex excitability together with 

 inaprovement of tone. 



Absorption and Elimination. Strychnine is rapidly absorbed 

 especially from the intestines and begins to be eliminated quite 

 quickly by the kidneys. Some is oxidized in the body and the re- 

 mainder is excreted in the urine. It can be found in the urine 

 within a few minutes after administration and most is excreted in a 

 few hours, although traces may be present for four or five days. 

 Cumulative action may take place if the drug is pushed to its limit 

 for some time, but is of rare occurrence. In strychnine poisoning. 



