Medical Treatment 



cians and nurses is essential (l\irinji- tlie entire 

 hospitalization period. 



SPECIFIC THERAPY 



Antivenin 



The early administration of antivenin, particu- 

 larly followiufj a se^■ere envenomation, cannot be 

 overemphasized. A few minutes may mean the 

 difference between life and death. The choice of 

 antivenin, the route of injection and the amount 

 to be g'wen will depend upon a number of dif- 

 ferent factors (see below). In most cases, the 

 more species oi- <i'enus specific the antivenin, the 

 more effective it will be. However, at the present 

 time tlieie is a great deal of variation in the 

 effectiveness of the commercially available anti- 

 venins; some polyvalent types appear to be more 

 u.sefiil than some which are genus specific. Un- 

 fortunately, there is no standardized process for 

 the production of antivenin, and indeed there is 

 no conformity in testing methods. Thus, the 

 physician will need to depend on the specific in- 

 formation supplied witli (he antivenin, or ujjon 

 more detailed data provided by a medical facility 

 in the area. Ampoules of antivenin usually have 

 an "expiration date" indicated, 'riiougli tiiis is 

 the limit of the pro<lurer"s pei'ind of potency, tlic 

 antivenin docs not suddenly become inell'ectixc 

 on that (late. Some ])ro(lucers have indicated 

 that the etl'ectiveness of the aiiti\cMin is not 

 greatly impaired until it has become cloudy or 

 milky in api)earanci'. A list of the a\'ailablc 

 antivenins is provided on ])ages ITiD-lTO. 



Certain ])rinciples can, however, guide the 

 physician in his choice of an antivenin. In 

 general, the lyophilized preparation is to l)e pre- 

 ferred to the nonlyophilized one; and antivenins 

 prepared by fractionation with anunonium sul- 

 fate, or some similar process f'oi' removing (he low 

 antibody containing fractions, are usually super- 

 ior to those in which the whole serum is packaged. 

 Almost all andvenins cui-rendy available ai'e i)re- 

 pared in hoi'ses, but widiin (he next few years 

 some antivenins will be prepared from sera of 

 other animals. 



The amount of antivenin re(piired to neutralize 

 the effects of a venom will depend upon a number 

 of different factors. However, some general in- 



structions can be given. Following appropriate 

 skin or eye tests, in cases of minimal envenoma- 

 tion, 1 or 2 units (vials, tubes or packages) will 

 usually suffice. Some manufacturers, however, 

 advise 3 or -1 units, even in relatively minor cases. 

 In moderately severe cases, 3 to 5 units may be 

 required; while in severe cases, 10 or more units 

 may sometimes be needed. "NAHiile as many as 45 

 units (450 ml. of antivenin) have been given to 

 a single patient, this is never warranted, and in- 

 deed is very dangerous. 



The choice of the route of administi'ation will 

 dejiend, among the other factors previously noted, 

 upon (he amount of (ime (hat has transpired be- 

 tween (he bite and the adminis(i-a( ion of (he anti- 

 venin. The longei' the delay (he more ni'gen( (he 

 m>ed for in(ra\euous an( ivenin. IIoweNer. no( all 

 ])roduc(s can be given in( ravenously with (he same 

 degree of safety. The physician should consult 

 (he bi-ochure which accompanies the an(ivenin 

 before injecting the serum. In(ravenous anti- 

 venin is also indicated for those patients in shock. 



In most cases, a portion of the first unit should 

 be injected subcutaneously jiroximal to the bi(e or 

 surrounding the wound or in advance of the 

 swelling. T'nder no ehTumxf(inee>i .ihoiild anti- 

 rrn/n be injected info a fnger or toe. Avoid giv- 

 ing large amounts of the antivenin into the in- 

 jured ])ar(. for (his makes it difficult to determiiu' 

 liow nuich swelling is due to the venom and how 

 much is due to the i)resence of antivenin. .V 

 second portion of the anti\enin should be in- 

 jected iiuranuiscularly into a large muscle mass 

 distaiu from the wound. The last portion of 

 the first uui( should be given in( ravenously, if 

 at all possible. It can 1h> added to a [)hysiol<)gic 

 saline solution and given in a contintious dri]). 

 Subseipient doses <-an then be ad<led to the saline 

 solut ion. 



Antix'enin is of \alue in lU'ut ralizing certain 

 effects of the venom, but perhaps not all. I( is 

 difficuU to determine how long after envenoma- 

 (ion an(ivenin can be given and still be effective. 

 Certainly, it is of value if given within 4 hours 

 of a bite; it is of lesser value if administration 

 is delayed for 8 hours, and it is of questionable 

 value after 10 hours, except j)erhaps in cases of 

 poisoning by certain elapids. It seems advisable 

 (o reconunend its use up to 12 hours following 

 en\enoma(ion, unless (here is a definite contra- 



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