Diphtheria Antitoxin 471 



alive seventy-five to one hundred and five days in dry air, 

 and one hundred and twenty days in moist air. 



Diphtheria Antitoxin. Behring * discovered that the 

 blood of animals rendered immune against diphtheria by 

 inoculation, first with attenuated and then with virulent 

 organisms, contained a neutralizing substance (Anti-korper] 

 capable of annulling the effects of the bacilli or the toxin when 

 simultaneously or subsequently inoculated into susceptible 

 animals. This substance, held in solution in the blood- 

 serum of the immunized animals, is the diphtheria antitoxin. 

 For method of preparing the antitoxins see Antitoxins. 

 The serum may be employed for purposes of prophylaxis or 

 for treatment. 



Prophylaxis. The serum can be relied upon for prophy- 

 laxis in cases of exposure to diphtheria infection. In most 

 cases a single dose of 500 units is sufficient for the purpose. 

 The protection thus afforded does not continue longer than 

 about three months. The transitory nature of the immun- 

 ity afforded by prophylactic injections of antitoxin is prob- 

 ably dependent upon the fact that the antitoxin is slowly 

 excreted through the kidneys. 



Treatment. Diphtheria antitoxin is always to be admin- 

 istered by the hypodermic method at some point where the 

 skin is loose. Some clinicians prefer to inject into the ab- 

 dominal wall; some, into the tissues of the back. A slightly 

 painful swelling is formed, which usually disappears in a short 

 time. In a few cases sudden death, with symptoms sug- 

 gesting anaphylaxis (q. v.), has followed the injection. 



Ehrlich asserts that a dose of 500 units is valueless for the 

 treatment of diphtheria, 2000 units being probably an aver- 

 age dose for an adult and 1000 units for a child. As the 

 remedy is practically harmless, it is far better to err on the 

 side of administering too much than on that of not enough. 

 Forty thousand units have been administered to a moribund 

 child with resulting cure. The administration of the 

 remedy should be repeated in twelve hours if the disease 

 is one or two days old, in six hours if three or four days old, 

 in four hours if still older. The serum may have to be given 

 two, three, four, or even more times, according to the case. 

 Occasionally there is an outbreak of local urticaria rarely 

 general urticaria. Sometimes considerable local erythema 



*" Deutsche med. Wochenschrift," 1890, Nos. 49 and 50; "Zeit- 

 schrift fiir Hygiene," xn, i, 1892. 



