Wednesday, September 16, 2009

How Is Antivenom Made

The first antivenom was developed for use against the cobra.


Antivenom is a biological product that is created to treat the venomous bites and stings of poisonous animals. Though snake antivenom is the most famous, antivenom has also been produced to successfully treat spider bites, scorpion stings and jellyfish attacks.


Types


Antivenom can be divided into two types. Monovalent antivenom is only useful for treating the bite of one specific species. Polyvalent antivenom can be used to treat bites or stings from different species. For example, there is no specific antivenom for the Australian copperhead, so instead a polyvalent antivenom must be used.


Production








Antivenom is created by extracting venom, or poison, from the animal whose bite needs to be treated. In snakes, this refers to a process known as milking. Another animal, like a sheep, a rabbit or a horse, will be injected with between 1/10th to 1/100th of one lethal dose of the venom. Over the span of several weeks, the animal will be injected with an increasing amount of the venom until it can comfortably handle a dose that is several times larger than the initial lethal dose. Then blood is drawn from the animal and centrifuged, which will separate the white blood cells from the red blood cells. The white blood cells contain powerful antibodies that fight off the effects of the venom, and they are the antivenom that is sent off to the hospitals.


Time Frame


Antivenoms need to be administered to the patient as soon as possible after a bite. In the case of snake bites, the antivenom should ideally be administered within four to five hours.


History


The first antivenom developed was meant for use on snakes. It was created in 1895 by Albert Calmette and it was meant for use against the bite of the Indian naja snake, which was another name for the cobra. After that, many antivenoms were developed during the 19th century. During this time, antivenoms were developed for scorpions, spiders and poisonous frogs and toads.


Potential


There is some hope that future antivenoms will be cheap, have a broad application, able to be taken orally, and derived from synthetics to remove the risk to human and animal participants. While there is no antivenom that meets all of these qualifications, there is progress. For instance, the use of sheep and goats rather than horses seems to produce antivenom that is less allergenic, and the use of antivenoms taken from avian eggs seems to be more robust than those taken from other animals.

Tags: antivenom that, blood cells, antivenom developed, antivenoms were, antivenoms were developed