Anesthetic (redirected from ester anesthetic)

anesthetic

Agent that produces a local or general loss of sensation, including pain, and therefore is useful in surgery and dentistry. General anesthesia induces loss of consciousness, most often using hydrocarbons (e.g., cyclopropane, ethylene); halogenated (see halogen) hydrocarbons (e.g., chloroform, ethyl chloride, trichloroethylene); ethers (e.g., ethyl ether or vinyl ether); or other compounds, such as tribromoethanol, nitrous oxide, or barbiturates. Local anesthesia induces loss of sensation in one area of the body by blocking nerve conduction (see nervous system, neuron), usually with alkaloids such as cocaine or synthetic substitutes (e.g., lidocaine). See also anesthesiology.

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anaesthetic (US), anesthetic

a substance that causes anaesthesia

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anesthetic [¦an·əs¦thed·ik]

(pharmacology)

A drug, such as ether, that produces loss of sensibility.

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Anesthetic 

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.

REFERENCE

Zakusov, V. V. Farmakologiia nervnoi sistemy. Leningrad, 1953.

V. V. PARIN