Local anesthetics reduce or completely suppress the excitability of sensory nerve endings in the mucous membranes, skin and other tissues in direct contact. Depending on the method of application of local anesthetic distinguish between terminal anesthesia (anesthetic is applied to the surface, where it blocks the end of the sensitive nerves), infiltration (the anesthetic solution is consistently "impregnate" the skin and deeper tissues), conduction (the anesthetic is injected along the nerve, causing the block of conduction of excitation along the nerve fibers), spinal anesthesia (subarachnoid anesthetic is administered).
The first substance that has discovered exhibits activity, was the alkaloid cocaine. Due to the high toxicity it is currently almost not used. In modern anesthesiology is the use of a number of synthetic local anesthetics. These include procaine, trimekain, tetracaine (mainly in ophthalmology), lidocaine. Recently with long-established local anesthetics (bupivacaine, etc.).
The scope of different drugs depending on their pharmacological and physico-chemical properties: benzocaine as an insoluble substance applies only superficially. Soluble drugs are used for different types of local anesthesia.
Some local anesthetics possess anti-arrhythmic activity. Lidocaine has a relatively wide application in certain types of arrhythmias. For the same purpose is used trimekain.