The effect of different snake venoms and anti-venoms on thrombin clotting time in human plasma.

BACKGROUND

Crotaline snake species, or pit vipers, are distributed throughout Asia and America. While much is known about the clinical effect of these snake venoms, there is a lack of evidence related to the various anti-venoms available and their effectiveness in reversing the effect of different venoms.

AIM: This study aimed to determine the interaction of the venoms of the following species: Crotalus unicolor, Crotalus adamanteus, Crotalus vegrandis, Trimeresurus spp, Calloselasma rhodostoma, Bothriechis schlegelii and Agkistrodon and the following anti-venoms: Anticrotalico, Antivipmyn, Antibotropico, Antifidico and SAIMR by evaluating their effect on the thrombin clotting time in human plasma.

METHOD: The interactions of venoms and anti-venoms were evaluated using thrombin clotting time in human plasma.

RESULTS

The results demonstrate that Anticrotalico anti-venom was most effective for the Crotalid species (Crotalus unicolor, Crotalus adamanteus, Crotalus vegrandis). Anticrotalico extended the time to clot formation 2.7 fold for Crotalus Unicolor, 3 fold for Crotalus Adamanteus and 4.6 fold for Crotalus Vegrandis. The anti-venoms most efficient in reversing the effect of the Trimeresurus spp venom, were Anticrotalico, Antivipmyn, Antibotropico and Antifidico anti-venoms, which all completely reversed the effect of clot formation as evident by no clot formation within the 999 seconds measurement limit. Bothriechis schlegelii venom was neutralized by all anti-venoms tested. Calloselasma rhodostoma venom was neutralized by Antifidico as well as Anticrotalico. The most efficient anti-venoms against the Agkistrodon venom were Anticrotalico and Antibotropico. In general, monovalent anti-venoms had improved efficiency for their corresponding snake species, depending highly on the composition of the snake venom. This study confirms the importance of considering the choice of anti-venom in a clinical setting, to reverse the effect of specific snake venoms. In addition, this study suggests that some anti-venoms can be considered for use against a variety of snake-venoms.