Effect of Habu (Trimeresurus flavoviridis) antivenom on changes of hemostatic parameters following administration of crude venom from T. flavoviridis in rabbits.

We carried out experiments to examine the efficacy of Habu antivenom in relation to variations of hemostatic parameters induced by the administration of crude venom to rabbits. For neutralization of the crude venom by Habu antivenom, the correlation between the concentrations of Habu antivenom (Y) and crude venom (X) was expressed by the equation: Y = -0.473 + 0.539X. We examined the variations in hemostatic parameters in the state which crude venom was neutralized by Habu antivenom following the administration of crude venom (1 mg/kg) from Trimeresurus flavoviridis. Although the hemostatic parameters [level of fibrinogen, antithrombin III (AT-III) activity and alpha 2-plasmin inhibitor (alpha 2-PI) activity] underwent decreases after the administration of crude venom, they revealed fluctuations within the normal range after the Habu antivenom administration. The AT-III activity, however, decreased gradually until 90 min after the antivenom administration. These results suggested that Habu antivenom was effective in improving the abnormal coagulant activity induced by crude venom. However, the neutralization effect towards the coagulant activity of crude venom by the Habu antivenom did not continue for a long time and did not lead to recovery of the AT-III activity. Since excessive doses of antivenom can induce serious medical problems, we expect that simultaneous use of antivenom and AT-III preparation, instead of excessive and single use of Habu antivenom could provide a useful therapy for snake bites from the present study.