The latest info i have received had been from Dr Sean Bush. For most envenomations of snakes in the US, the primary tx is calm down, clean the wound, seem medical attention...........most of the time an average adult can usuallly withstand a bite. Course it all depends on the amount of venomation injected. He noted the various treatment modalities out there. But for the most part, due to the tachycardic state most victims are in due to the "shock " from being bitten, usually the venom is in full steam by the time anyone could ever consider really trying to reverse anything. Shock therapy and the old familiar saywer extractor both and contribute to as well and hinder the help your seeking. Both can cause localized necrosis of the area due to cellular disruption due to current altering the tissue membranes and or from the negative pressure of a suction device. The only current treament for anything lately i've heard is for Elapid (coral) snakes and that is to keep the wound at heart level and wrap it if its a limb with an ace wrap..
With any form of treament, the best place to start is considering the type of venom itself, wether it be hemotoxic or neurotoxic, etc...
Course if your in "aussie" country and its a Taipan envenomation...........well pray, and start bustin ass toward a hospital!