Editing General anaesthetic (section)

=== Intravenous general anesthetics ===

====Induction====

Intravenously delivered general anesthetics are typically small and highly [[Lipophilicity|lipophilic]] molecules. These characteristics facilitate their rapid preferential distribution into the brain and spinal cord, which are both highly vascularized and lipophilic. It is here where the actions of these drugs lead to general anesthesia induction.<ref name=":16" />

====Elimination====
Following distribution into the [[central nervous system]] (CNS), the anesthetic drug then diffuses out of the CNS into the muscles and viscera, followed by [[adipose tissue]]s. In patients given a single injection of drug, this redistribution results in termination of general anesthesia. Therefore, following administration of a single anesthetic [[Bolus (medicine)|bolus]], duration of drug effect is dependent solely upon the redistribution kinetics.<ref name=":16" />

The [[half-life]] of an anesthetic drug following a prolonged infusion, however, depends upon both drug redistribution kinetics, [[drug metabolism]] in the liver, and existing drug concentration in fat. When large quantities of an anesthetic drug have already been dissolved in the body's fat stores, this can slow its redistribution out of the brain and spinal cord, prolonging its CNS effects. For this reason, the half-lives of these infused drugs are said to be [[Context-sensitive half-life|context-dependent]]. Generally, prolonged anesthetic drug infusions result in longer drug half-lives, slowed elimination from the brain and spinal cord, and delayed termination of general anesthesia.<ref name=":16" />