STRYCHNINE 301 



advised, to the weight of the animal. Five to eight grains of nux vomica 

 will kill dogs. 



The minimum fatal dose of strychnine for man is one-half a grain. 

 Usually four to seven grains constitute a lethal quantity, but recovery 

 has ensued following the ingestion of 22 grains, after a full meal. 



Horses. — The toxic symptoms in horses resemble those already de- 

 scribed in the dog. They do not appear for some time (20 minutes to 6 

 hours), depending on the rapidity of absorption wjien the drug is swal- 

 lowed, and include excitement, muscular spasm and convulsions, increased 

 frequency of the pulse, and difficult respiration. Death occurs in con- 

 vulsions or in the interim between them. The minimum fatal dose of 

 strychnine, when given under the skin, is about ll/^ to 3 grains, and when 

 swallowed, 3 to 5 grains of the alkaloid, or 1 to 2 ounces of nux vomica. 

 A 1000-pound mare having clonic spasms in early stages of azoturia died 

 with typical symptoms of strychnine poisoning within three minutes of 

 receiving one grain of strychnine subcutaneously. 



Cattle are similarly affected with horses and dogs. There are exhib- 

 ited muscular spasms, frequent pulse, difficult respiration, sensitiveness 

 to light, sounds and external stimuli, protrusion of the eyeballs and con- 

 vulsions. The fatal dose, by the mouth, varies greatly owing to difficulty 

 of absorption in the complicated and capacious digestive apparatus of 

 these ruminants. This is true of all medicines. When given under the 

 skin, the lethal dose is a little larger than that for horses. The fatal dose 

 for swine is said to be from gr. l/6-gr. 3/4. Chickens are comparatively 

 insusceptible; also guinea pigs and some monkeys. 



Strychnine poisoning differs from tetanus in the fact that muscular 

 rigidity is continuous in the latter, but disappears to a considerable 

 degree, if not completely, in the periods between the convulsions, in the 

 case of strychnine poisoning. Moreover, in tetanus the body and limbs 

 are less, and the jaw more affected; while in strychnine poisoning the 

 condition is reversed. 



Treatment. — fhe treatment embraces the use of chemical antidotes, 

 as iodine or its salts, or tannic acid; animal charcoal and emetics or 'the 

 stomach tube, before absorption has occurred. Chloroform, chloral and 

 amyl nitrite were formerly considered the best antidotes to strychnine 

 but recent experiments prove these too depressant to the respiratory 

 centres. Artificial respiration is of service in paralysis, but not in con- 

 vulsions, unless air be forcibly driven into the trachea through a catheter. 

 The best treatment consists in ether anesthesia, intratracheal insufflation 

 and intravenous saline infusion (Githens & Meltzer, 1912). 



Post-Mortem Appearances. — These are simply those of asphyxia, 

 with the usual congestive lesions and dark fluid blood, except spinal 

 hyperemia is observed. 



Uses Internal. — The indications for the employment of strychnine 

 may be directly deduced from its .physiological actions. The indications 

 are as follows: 



1. To stimulate the respiratory and vasomotor centres and nervous 

 system. 



Digitized by Microsoft® 



