What natural substance was the first local anesthetic to be introduced into medicine?
Cocaine. Credit for the discovery of cocaine as a local anesthetic is usually attributed to Dr. Carl Koller, an Austrian opthamologist who in 1884 demonstrated that dropping a solution of cocaine into the eyes of frogs and guinea pigs produced a local anesthetic effect. He then went on to experiment on some of his colleagues and on himself, clearly proving that cocaine drops effectively desensitized the eye. While Koller was the first to use cocaine as an anesthetic in eye surgery, he was not the first to note the local anesthetic effect of the compound that occurs naturally in the leaves of the south American coca plant. That honour actually goes to Friedrich Wohler, the German chemist who is regarded as the father of modern organic chemistry. Wohler had garnered scientific fame by making urea, a compound found in human urine, from ingredients that did not come from living sources. With this single experiment he destroyed the notion that substances found in living systems, which at the time were referred to as “organic,” could not be reproduced in the laboratory because they contained some sort of “vital force.” Years later, Albert Niemann, working in Wohler’s lab at the University of Gottingen isolated the active principle of the coca shrub, which Wohler then named “cocaine.” He noted that when applied to the tongue cocaine had a numbing effect, but never exploited the discovery. The idea of using cocaine as an anesthetic was actually Sigmund Freud’s. The famed Viennese physician, who would come to be known as the father of psychoanalysis, had a notion that cocaine could be used in the treatment of morphine addiction. During the course of this investigation Freud found that rubbing cocaine on the skin led to a loss of sensation and brought this to the attention of colleague Carl Koller who went on to use the drug successfully in eye surgery. Freud would likely have shared the credit for discovering the local anesthetic effect of cocaine had he not left Vienna to pursue his future wife, Martha Bernays. This chase apparently was also a result of Freud’s experimenting with cocaine and his discovery that ingesting a small dose of the drug increased his libido. Freud excitedly wrote to his fiancée, “woe to you, my princess, when I come. I will kiss you quite hard and feed you until you are plump. And if you willfully resist, you shall see who is stronger, a gentle little girl who doesn’t eat enough or a big wild man with cocaine in his body.” History does not record the result of this contest or whether Freud needed cocaine to sweep Martha off her feet. Today, cocaine is still sometimes used in ear, nose or throat surgery, but it has largely been replaced by other local anesthetics such as procainamide, synthetics modeled on the molecular structure of cocaine.