Bothrops
venoms are rich in
enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e.,
calcium and
phospholipids, while
antivenoms variably neutralize
venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus
venoms; (ii) to study their activity on the whole blood using rotational thromboelastometry (ROTEM); (iii) to evaluate the contribution of
calcium and
phospholipids in their activity; and (iv) to compare the effectiveness of four
antivenoms (Bothrofav™, Inoserp™ South America, Antivipmyn™ TRI, and PoliVal-ICP™) on the procoagulant activity of these two
venoms.
Venom composition was comparable. Both
venoms exhibited hypercoagulant effects. B. lanceolatus
venom was completely dependent on
calcium but less dependent on
phospholipids than B. atrox
venom to induce in vitro coagulation. The four
antivenoms neutralized the procoagulant activity of the two
venoms; however, with quantitative differences. Bothrofav™ was more effective against both
venoms than the three other
antivenoms. The relatively similar
venom-induced effects in vitro were unexpected considering the opposite clinical manifestations resulting from envenomation (i.e., systemic
bleeding with B. atrox and
thrombosis with B. lanceolatus). In vivo studies are warranted to better understand the pathophysiology of systemic
bleeding and
thrombosis associated with Bothrops
bites.