SERUM ANTITETANICUM SICCUM 461 



administered subcutaneously, as soon as possible after the discovery of 

 the disease. Every hour's delay is dangerous. For cases seen more than 

 twenty-four hours after onset, for cases with membrane extending beyond 

 the tonsils, or for cases with severe symptoms or seen to be of virulent, 

 rapidly spreading type, the dose should at least be doubled. 



The site of injection is usually the loose tissues of the back. In severe 

 cases it is preferable to use the intravenous route in addition to the sub- 

 cutaneous, because absorption from the subcutaneous tissue is slow. The 

 intravenous injection should not be given more rapidly than i mil per 

 minute. The serum should be free from sediment and warmed to body 

 temperature. On account of the saving of time in this method of admin- 

 istration the dose need only be one-half or one-fourth as great as that 

 necessary for subcutaneous administration in the given case. Sufficient 

 antitoxin should be given at the initial treatment to arrest and cure the 

 disease, but if the amount necessary has been underestimated the dose 

 may be repeated once in six hours or increased. The prophylactic dose 

 is 1000 units; for very young infants, 500 units. This should be repeated 

 every two weeks if exposure continues. 



The preparation consists of a solution of certain antitoxin proteins 

 in physiologic sodium chloride solution. The antitoxin proteins are 

 separated from the native antitetanic serum by precipitation with am- 

 monium sulphate. The precipitate is then dissolved in saturated sodium 

 chloride solution and the salts are removed by dialysis. After dialysis is 

 complete, sufficient sodium chloride is added to make an 0.8 per cent, 

 solution. Concentrated tetanus antitoxin is a transparent or slightly 

 opalescent liquid, sometimes with a slight granular or ropy sediment; it 

 may be more or less viscous. Its actions and uses are the same as those 

 of tetanus antitoxin, unconcentrated. 



SERUM ANTITETANICUM SICCUM, U.S.P. This dried serum 

 is either in the form of orange or yellowish flakes or small lumps, or a 

 yellowish-white powder without odor. The serum is readily soluble in 

 nine parts of distilled water, the solution being opalescent and slightly 

 viscous. For use the serum must be dissolved in recently boiled and 

 cooled distilled water, preferably in the original container and under the 

 most rigid aseptic conditions. Dried antitetanic serum if kept as directed 

 does not lose in potency, as does the liquid serum. It is sometimes used 

 .as a dusting powder or for local application to infected wounds. It must 

 comply with the requirements for control and labeling under Serum 

 Antitetanicum and the standard of strength, expressed in units of antitoxic 

 power, shall be that established by the United States Health Service. 



This serum is prepared from tetanus antitoxin by a method similar 

 to that used in preparing diphtheria antitoxin, dried. 



Antitoxins keep their potency longer in the dry than in the liquid state. 

 .A powdered form of this preparation may be used in wounds as an addi- 



