Most three-finger toxins kill the nerve cells they stick to, but that doesn’t seem to be the case with mambalgins. In fact, animal testing revealed that the mambalgins “do not produce motor dysfunction, apathy, flaccid paralysis, convulsions or death upon central injections.”

http://gizmodo.com/5948959/snake-venom-might-actually-be-a-better-painkiller-than-morphine