Cross reactivity of three antivenoms against North American snake venoms.

The antivenom in the United States today is in short supply, expensive and may not even be the most effective in neutralizing venoms from snakes in certain geographical locations. The ED(50) is considered to be the best indicator of antivenom efficacy, however, other tests are needed. In this study, three antivenoms (Antivipmyn (Fab(2)H), Crotalidae Polyvalent Immune Fab (Ovine) (FabO) and UCV (FabV) were used to test the effectiveness of neutralization of eight venoms (Agkistrodon piscivorus piscivorus, Bothrops asper, Crotalus adamanteus, C. durissus durissus, C. horridus atricaudatus, C. h. horridus, C. atrox, and C. molossus molossus). Four different assays were used to study the efficacy of the antivenoms: the antihemorrhagic, antigelatinase, antifibrinolytic and antihide powder azure. Fab(2)H antivenom was more effective in neutralizing the enzymatic activities of these eight venoms than FabO and FabV antivenoms.