Abstract:
Russell's viper is the most important cause of life-threatening snake
bite and acute renal failure in Sri Lanka. Only equine polyspecific antivenoms
imported from India are available. They have not proved effective clinically or in
clearing venom antigenemia and they frequently cause reactions. In an attempt to
reduce mortality and morbidity, a newmonospecific ovine Fab fragment
antivenom (PolongaTab; Therapeutic Antibodies, Inc., London, United Kingdom)
was raised against Sri Lankan Russell's viper venom. In a preliminary dosefinding study in 35 patients, an initial dose of 3-4 g restored blood coagulability
permanently and stopped systemic bleeding, even in severely envenomed patients.
Venom antigenemia disappeared within 1 hr of antivenom treatment but recurred,
probably as a result of continued absorption of venom from the site of the bite,
after the rapid clearance of therapeutic antibody. Twelve patients (34%)
experienced early reactions that were usually mild and always responded to
epinephrine.
