134 MEDULLA 



The minimal lethal dose of epinephrine administered sub- 

 cutaneously to man is from 10 to 20 mgms. per kilo of body- 

 weight; intravenously it is 0.1 to 0.25 mg. per kilo. Alarming 

 symptoms have followed the intravenous injection of 0.3 

 mgm. As little as 4 mgms. subcutaneously has proven fatal. 638 



The lethal dose for the rabbit per kilo of body weight is 

 0.05 to 0.4 mgm. administered intravenously. For the dog or 

 cat the lethal dose is 0.2 to 0.8 mgms. per kilo. 638 



The paralysis and convulsions which follow lethal doses of 

 epinephrine are results of changes in the central nervous sys- 

 tem presumably caused by vascular constriction. At autopsy, 

 one finds multiple hemorrhages throughout the body. The 

 heart is dilated. The lungs are edematous and filled with 

 blood. Hemorrhage is also found in the other serous cavities 

 and in the kidney. The pupils are dilated and the eyeballs 

 project due to sympathetic stimulation. 



The effects of sub-lethal doses of epinephrine is cumulative 

 so that the injection of a lethal dose in two injections with an 

 interval of some hours between the injections may still prove 

 fatal. Atropine is a valuable antidote. 639 



THERAPEUTIC USES OF EPINEPHRINE 



The versatile effects produced by the administration of 

 epinephrine have given it wide usefulness in practical thera- 

 peutics. 



Epinephrine receives wide application in conjunction with 

 the use of local and spinal anesthetics. Here it acts by aiding 

 the production of a bloodless field and, by preventing rapid 

 absorption of the anesthetic, prolongs the period of anesthesia, 

 maintains a high concentration of the anesthetic locally, and 

 prevents toxicity due to its absorption. 



The stimulating effect of epinephrine on the heart renders it 

 useful as an analeptic. When injected directly into the car- 

 diac muscle, the heart which has stopped may resume its beat, 

 particularly with the aid of massage. Epinephrine has been 



