Alfred Einhorn (1856–1917)
Novocain is so ingrained in our drug vocabulary that it needs little explanation. When visiting dentists, we are told that we will first be given a “shot of Novocain to numb the tooth.” Although it’s highly unlikely that we are getting the “real” Novocain, we are getting a first cousin that acts in a similar manner. Nevertheless, for more than a hundred years, Novocain has remained a synonym for a local anesthetic—a drug that causes a loss of sensation of pain in a restricted or localized site, without altering consciousness.
Cocaine, a naturally occurring chemical isolated from the coca leaf, was the first local anesthetic, introduced in 1884. It was highly effective but toxic, causing a number of fatalities and addictions—a limitation recognized within a few short years. In 1892, German chemist Alfred Einhorn, a professor at the University of Munich, began his search for a safer alternative that was not subject to abuse. After multiple attempts at finding a suitable chemical, in 1905 Einhorn discovered the first injectable local anesthetic, procaine, which was given the trade name Novocain.
After Novocain is injected, it rapidly gains access to the bloodstream and is rapidly inactivated by the enzyme cholinesterase. Hence, it is usually given in combination with epinephrine/adrenaline, which constricts blood vessels in order to prolong the time Novocain will continue to act and to reduce the likelihood that large amounts will enter the circulatory system and cause toxicity. Unlike cocaine, Novocain is ineffective when applied topically.
Following the appearance of Novocain, hundreds of potential local anesthetics have been synthesized, which by convention end in -caine. Some two dozen have been marketed for use by injection or local application and occasionally both. Procaine remained the primary local anesthetic until 1948, when Xylocaine—a superior drug that can be applied topically or injected—was introduced.
SEE ALSO Coca (1532), Cocaine (1884), Epinephrine/Adrenaline (1901), Xylocaine (1948).
This painting by Johann Liss (c. 1597–1631), based on a copper engraving by Lucas van Leyden (1494–1533), depicts a medieval dentist removing a tooth—without the benefit of Novocain.