The effects of specific antibody fragments on the 'irreversible' neurotoxicity induced by Brown snake (Pseudonaja) venom.

Brown snake (Pseudonaja) venom has been reported to produce 'irreversible' post synaptic neurotoxicity (Harris & Maltin, 1981; Barnett et al., 1980). A murine phrenic nerve/diaphragm preparation was used to study the neurotoxic effects of this venom and pre- and post-synaptic components were distinguished by varying the temperature and frequency of nerve stimulation. There were no myotoxic effects and the neurotoxicity proved irreversible by washing alone. The effects of a new Fab based ovine antivenom have been investigated and proved able to produce a complete, rapid (< 1 h) reversal of the neurotoxicity induced by Brown snake venom. A reversal was also possible when the antivenom addition was delayed for a further 60 min. We believe that this is the first time such a reversal has been shown.