Developed in the late 1800s, Diphtheria-antitoxin is a medication made up of antibodies used in the treatment of diphtheria. However, it is no longer recommended for prevention of diphtheria. For those who don’t know what Diphtheria is, it is actually an infectious disease caused by the bacterium Corynebacterium diphtheria, which primarily infects the throat and upper airways, and produces a toxin affecting other organs. The illness has an acute onset and the main characteristics are sore throat, low fever and swollen glands in the neck. Besides, the toxin may, in severe cases, cause myocarditis or peripheral neuropathy. Basically, Diphtheria-antitoxin counters the effects of the diphtheria toxin by neutralizing them. As for the side effects of this drug, they include serum sickness and allergic reactions. Bear in mind that Diphtheria-antitoxin should be used cautiously during pregnancy.