Anesthetic(redirected from topical anesthetic)
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a substance that acts selectively on the central nervous system and induces a state of anesthesia.
The meaning of the term “anesthetic” has changed in the course of the development of pharmacology. Anesthetics used to include nervous-system depressants and stimulants, as well as many substances that only indirectly affect the nervous system. From the beginning of anesthetic practice, stimulants, depressants, and various indirectly acting substances were the principal anesthetics. Neurotropic agents with different types of action, for example, analgesic, somnifacient, and tranquilizing, are grouped separately. Application of the term “anesthetic” to denote substances of plant or synthetic origin that are narcotics—morphine, oxycodone, Trimeperidin. for instance—was determined by convention, as was the use of the term “narcotic” to convey the sense of “anesthetic.” The main requirements of an anesthetic are that it have broad action, that is, a significant range between the effective (anesthetic) and toxic doses; that it not produce complications; and that it have no aftereffects.
Anesthetics are classified as either inhalation or noninhalation, depending on the method of administration. Inhalation anesthetics are divided into volatile anesthetics, which include ethers, chloroform, trichloroethylene, halothane, and ethyl chloride, and into gaseous anesthetics, such as nitrous oxide and cyclopropane. Noninhalation anesthetics, for example, hexobarbital, sodium thiopental, and propanilid, are administered intravenously. Narcolan is introduced by rectum.
Often, a combination of anesthetics is used to weaken or completely compensate for any negative properties that one of the ingredients might have when used alone. Surgical procedures that involve certain physiological functions can require a combination of an anesthetic with other types of agents, such as muscle relaxants, antihistamines, cholinergic and adrenergic blocking agents, ganglioplegic agents, neuroleptics, and tranquilizers. A new kind of anesthesia has been developed, neuroleptoanalgesia, in which anesthesia is brought about using neuroleptics and analgesics without the use of anesthetics.
REFERENCEZakusov, V. V. Farmakologiia nervnoi sistemy. Leningrad, 1953.
V. V. PARIN
What does it mean when you dream about an anesthetic?
To dream of being anaesthetized may represent the residue of a memory (e.g., from a medical operation). It could also reflect a desire to be relieved of some painful experience—physical, mental, or emotional.