International Association Against Painful Experiments on Animals

Alternatives To Animal Experiments Research Testing

14: Page 14

The first local anesthetic was cocaine, and its use for such a purpose was first suggested by Sigmund Freud.(6) Cocaine, a derivative of the coca leaf, had been used for pleasure as well as for medical purposes for centuries in South America, and by the 1870s several doctors had testified to its benefits in a wide variety of conditions. Then, in 1883, Freud commenced his own research, carefully experimenting on himself. He noticed that cocaine numbed the tongue and cheeks, and while others had described the same lack of sensation in the past, none had had the ingenuity to apply it to surgery.

Freud described cocaine's numbing effects to an ophthalmologist friend, Dr Carl Koller, who had been searching for an anesthetic for eye surgery. Strangely, in view of cocaine's long history of use, Koller carried out preliminary experiments on animals before doing the same tests on himself and an assistant. A solution of cocaine was applied to the eye, which was then assessed for sensitivity. The tests were repeated on other colleagues and on patients. They worked: cocaine could be used as a painkiller for people with eye conditions and as a local anesthetic for eye surgery.

Today, the most widely used local anesthetic is lignocaine, which resulted from a chemist's habit of tasting all the compounds he produced.(21) In 1935, Holger Erdtman at the University of Stockholm synthesized a chemical called isogramine. As was his practice, Erdtman tasted a trace of the substance and discovered that his tongue went numb! Using isogramine and another similar "tongue numbing" chemical as their starting point, Erdtman and his research student synthesized a further 57 closely related analogues to find the most effective. Bergt Lundqvist, a colleague, tested compound LL30 on himself and suggested its full evaluation at the Karolinski Institute. LL30 turned out to be lignocaine, subsequently marketed by Astra in 1948.


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