Anesthetics refer to a class of compounds used to produce local or general anesthesia effects, rather than specifically denoting a single biomolecule. They can be in the form of gases, liquids, or solids, such as halothane or lidocaine, acting on the central nervous system by blocking nerve signal transmission, reducing or eliminating the perception and response to pain. Anesthetic molecules typically alter the activity of specific ion channels, such as sodium channels or GABA receptors, through interactions, leading to the blockade of nerve signal conduction. Their effects and side effects may be influenced by genetic differences, as certain genetic variations can change an individual's sensitivity to anesthetic drugs or their metabolic rate.