Comparative study of the efficacy and safety of two polyvalent, XXXX fractionated [IgG and F(ab')2] antivenoms, in Bothrops asper bites in Colombia.

@entity1 @entity6212 @entity548 @entity908 @entity2688 @entity1003 @entity733 @entity751 @entity810
The efficacy and safety of two polyvalent horse-derived antivenoms in Bothrops asper envenomings were tested in a randomized, double-blind, clinical trial performed in Colombia. Both antivenoms were manufactured from the same pool of hyperimmune plasma. Antivenom A was made of F(ab')2 fragments, generated by pepsin digestion and @entity6212 precipitation, whereas antivenom B consisted of whole IgG molecules produced by @entity6212 precipitation followed by ion-exchange chromatography. Besides the different nature of the active substance, antivenom B had higher protein concentration, slightly higher turbidity and aggregate content. No significant differences were observed in the efficacy of antivenoms. Both halted local and systemic @entity548 (P = 0.40) within 6-12 h of treatment in 100% of the cases, and @entity1003 (P = 0.87) within 6-24 h in 84.7% of @entity1 , and within 48 h in all of them, in agreement with restoration of plasma fibrinogen concentration. Venom concentrations in serum dropped significantly (P < 0.001), to very low levels, 1 h after antivenom infusion. Nevertheless, eight @entity1 (11.1%), four for each antivenom, presented recurrence of venom antigenaemia at different times, from 6 to 96 h, with clinical significance ( @entity1003 ) only in one group B @entity1 (2.9%). Serum @entity908 kinase (CK) activity was increased, as a consequence of local myonecrosis. There was no significant difference (P = 0.51) in the incidence of early adverse reactions to antivenom administration (28.9% for @entity1 of group A and 20.6% for @entity1 of group B), most of the reactions being mild, mainly cutaneous. The most frequent complications were @entity2688 (16.7%), @entity733 formation (5.6%), @entity810 (8.3%), and @entity751 (5.6%). In conclusion, IgG and F(ab')2 antivenoms, prepared by @entity6212 fractionation, presented similar efficacy and safety profiles for the treatment of B. asper envenomings in Colombia.
