Antivenin
An antivenin or antivenome is an immune serum specially developed for the treatment of bite injuries caused by poisonous animals . Antivenins are used against bites from snakes , scorpions , spiders , cone snails and box jellyfish . As a rule, individual antivenins can only be used for bites by one species or members of a closely related group of species. Commercially available products are therefore polyvalent mixtures of different serums, e.g. As the snake venom immune serum "Europe" according to the European Pharmacopoeia ( viper , viper , sand viper , asp , Levante Viper ).
Snake antivenins
There are around 400 poisonous species of snakes worldwide (out of a total of 3,400), almost all of which are native to the tropics and subtropics . Worldwide it is estimated that around 10 million snakebites per year cause 125,000 deaths. In Central Europe, however, there are only a few venomous viper species ( horned viper , viper ), whose bites also are rarely life-threatening (about 2% lethality). The few deaths reported in recent years were caused by privately owned tropical venomous snakes (as of 2010).
Snake poisons are mixtures of numerous enzymes that are toxic to nerve cells , blood vessel cells and / or blood cells . Appropriate antibodies are used as antivenins . To produce it, horses or sheep are exposed to toxins; the antibodies which are then formed are then extracted from the blood of the animals and concentrated.
Because of the high costs and limited shelf life, Antisera are only stored in centralized depots, in Germany mostly in the tropical medicine institutes of the university clinics . They may only be used by the doctor under inpatient conditions.
Debate about profitability
In 2016, the company Sanofi Pasteur MSD stopped the production of its highly effective combination antivenin Fav-Afrique for the treatment of patients after bites of the ten most important venomous snake species in the sub-Saharan region. The reason given was that African buyers had been buying cheaper Antivenine from other manufacturers since 2006, for example from India, so production was no longer economical. The World Health Organization pointed out, however, that by no means all competing products have the same effectiveness as Fav-Afrique . The reason for this are regionally different eating habits of snakes, so that even the poison of a single species can be composed differently and the research effort for the production of highly effective antivenins is correspondingly high. Sanofi Pasteur MSD then allegedly offered its technology to other companies for takeover. In the meantime, Latin American pharmaceutical manufacturers in particular, including a company from Costa Rica, are offering combination antivenins at cost price. In connection with the production stop of Fav-Afrique, critics spoke of a "vicious circle": Many poorer patients could not afford the expensive preparations, the demand remained low and the pharmaceutical industry was taking the serums off the market because of the lack of profits.
Recommendations for use
It can be assumed that only 50% of the venomous snake bites actually get poison into the wound, since the snakes also take so-called “defense bites ” or “ dry bites ” without injecting venom. The WHO only recommends the use of Antivenin for snakebites if there are clear symptoms of intoxication all over the body or severe complications from the bite wound.
Side effects
Since the antiserum produced in this way consists of animal protein, most patients develop serum sickness (immune reaction with fever, joint pain and rash). There is also a risk of severe allergic side effects including circulatory shock; therefore, antisera are only used in justified cases and proven severe poisoning by hospitals that are as specialized as possible.
literature
- World Health Organization: Progress in the characterization of venoms and standardization of antivenoms (= WHO Offset Publication. Vol. 58). World Health Organization, Geneva 1981, ISBN 92-4-170058-0 .
- G. Habermehl: Poison animals and their weapons. Springer-Verlag, 2013, ISBN 978-3-662-00554-5 , p. 10.
swell
- ↑ Steven Foster: A Field Guide to Venomous Animals and Poisonous Plants, North America, North of Mexico. Houghton Mifflin Harcourt, 1994, ISBN 978-0-395-93608-5 , p. 8.
- ^ Species Numbers. reptile-database, February 2014
- ↑ - ( Memento of the original from January 13, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ [1]
- ↑ Clara Hellner: Snakebites: It was the snake . In: The time . No. 02/2018 ( online ).
- ↑ David A. Warrell (Ed.): Guidelines for the management of snake-bites. (PDF) Regional Office for South-East Asia, 2010, ISBN 978-92-9022-377-1 .
