Administered intravenously into the victim's body, antivenom acts to neutralize the poisonous venom of the cobra and causes the venom to be released from the receptor site. Thus, the receptor sites that were previously blocked by venom are now free to interact with the acetylcholine molecule, and normal respiration resumes. The spent antivenom and the neutralized venom are then excreted from the body.
Venom composition (and its corresponding toxicity) can vary among cobras from the same species and even from the same litter--it can also vary for an individual cobra during its lifetime--and all of this makes each cobra bite truly unique. In order to insure correct treatment, antibodies specific to each form of cobra venom must be developed. The correct antibodies may be synthesized by injecting horses with a small amount of cobra venom, and then collecting the antibodies produced by the horses' immune systems. Of course, large samples of cobra venom must be collected for this process, and many snake farms around the world make significant amounts of money by harvesting the deadly snake toxin.