History of the development and evolution of local anesthesia since the coca leaf.

THE development of anesthesia in general and local anesthetics, in particular, required a cultural change. The concept of pain (especially obstetric pain) was linked to the concept of original sin, and the ability to endure pain was regarded as a sign of character and, in men, was even associated with virility. The change that took place in Western Europe between 1750 and 1850, encompassing the industrialization, progressive humanization, and democratization of society, created an atmosphere favorable to the discovery of anesthetics. Nothing comparable occurred in Asia, Russia, or the Islamic countries, where feudalism persisted in a variety of forms. This general process altered the cultural, political, and religious climate, affecting a significant number of individuals. Dentists, not doctors, were responsible for the discovery of anesthesia, given their close day-to-day contact with pain and, hence, their motivation to seek the means to alleviate it. Doctors focused more on infections than pain because people were dying of pneumonia, diphtheria, gangrene, tuberculosis, tetanus, puerperal fever, and so on. It was two dentists, then, who first introduced anesthesia: Horace Wells (1815–1848), with nitrous oxide in 1844, and William Thomas Green Morton (1819–1868), with ether in 1846. Local anesthesia, the basis of modern local anesthetics for dentistry and medicine, developed later. This article reviews the discovery and evolution of local anesthesia from the Spanish discovery of the coca leaf in America, outlining certain ill-known aspects of this early period.