Pharmacology of Local and Neuraxial Anesthetics

Local anestheticsLocal anesthetics are the pharmacologic cornerstone of regional anesthesiaAnesthesia producing reversible and complete blockade of neuronal transmission when applied near the axons. Development of local anesthetics, since the 1950s, has focused on amide local anesthetics. Ester local anesthetics exhibit several limitations including instability when in solution, short shelf life, degradation when exposed to high temperatures, and an increased propensity to cause allergic reactions. Local anesthetics are widely used to prevent or treat acute painAcute pain; to treat inflammatory, cancer, and chronic painChronic pain; and for diagnostic and prognostic purposes. Nociceptive pain, as well as neuropathic pain, is targeted with this group of drugs. Any part of the nervous system, from the periphery to the brain, may be where local anesthetics act to produce a desired anesthetic or analgesic effect. This chapter describes the basic chemical structure of local anestheticsLocal anesthetics and gives an overview of pharmacologic properties of the different drugs. Clinical use, advantages, and side effects are compared, and local anesthetic toxicity is described.