Some groups of drugs, e.g., anti-infectives, are undergoing a process of continual development. In contrast, the local anesthetics that are indispensable to attain freedom from pain in diagnostic and therapeutic interventions tend to be a rather quiescent group. Compared to general anesthetics, there are major regional differences in their proportional share in anesthetic techniques that vary between 5% and 70%. Despite the introduction of medical hypnosis, dental medicine is absolutely dependent on local anesthetics. Temporary abolition of pain sensation by chemical substances was achieved thanks to the Vienna ophthalmologist Karl Koller, who experimented with cocaine at the suggestion of Sigmund Freud.