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). &Seealso; anesthesiology.