The bushmaster (Lachesis muta) of Central and South America, the world
's longest pit viper, is capable of injecting a large dose of potent v
enom when it bites. A 28-year-old man, bitten by a 1.82 m long L. m. m
uta in Brazil, developed pain and oedema at the bite site, nausea, vom
iting, diarrhoea and sweating. There was peripheral neutrophil leucocy
tosis and evidence of fibrinogen consumption with secondary activation
of the fibrinolytic system. Two hours after the bite, eight ampoules
of Institute Butantan Lachesis antivenom was administered, and haemost
asis was normal 24 hr later. A review of reports of 20 cases of bites
in humans reliably attributed to this snake in Costa Rica, French Guia
na, Brazil, Colombia and Venezuela confirms a syndrome of nausea, vomi
ting, abdominal colic, diarrhoea, sweating, hypotension, bradycardia a
nd shock, possibly autopharmacological or autonomic in origin, not see
n in victims of other American crotaline snakes. These, and other symp
toms of bushmaster envenoming, art explained by haemorrhagic, coagulan
t and neurotoxic venom activities. The therapeutic efficacy of non-spe
cific Bothrops/Crotalus polyvalent antivenoms in these cases has been
unimpressive. For the treatment of bites by a snake which potentially
injects a large dose (> 300 mg dry weight) of venom with a range of li
fe-threatening activities, there is an urgent need to develop more pot
ent specific antivenoms and to treat the dramatic and life-threatening
cardiovascular symptoms. (C) 1997 Elsevier Science Ltd.