Antivenom

Antivenin (or antivenom or antivenene) is a biological product used in the treatment of venomous bites or stings. Antivenom is created by milking venom from a relevant snake, spider, insect, or fish. The venom is then diluted and injected into a horse, sheep, rabbit, or goat. The subject animal will undergo an immune response to the venom, producing antibodies against the venom's active molecules which can then be harvested from the animal's blood and used to treat envenomation. Internationally, antivenoms must conform to the standards of pharmacopoeia and the World Health Organization (WHO).

It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.

Medical uses

The principle of antivenom is based on that of vaccines, developed by Edward Jenner; however, instead of inducing immunity in the patient directly, it is induced in a host animal and the hyperimmunized serum is transfused into the patient.

Antivenoms can be classified into monovalent (when they are effective against a single species' venom) or polyvalent (when they are effective against a range of species, or several different species at the same time). The first antivenom for snakes (called an anti-ophidic serum) was developed by Albert Calmette, a French scientist of the Pasteur Institute working at its Indochine branch in 1895, against the Indian Cobra (Naja naja). In 1901, Vital Brazil, working at the Instituto Butantan in São Paulo, Brazil, developed the first monovalent and polyvalent antivenoms for Central and South American Crotalus and Bothrops genera, as well as for certain species of venomous spiders, scorpions, and frogs.