Voltage-gated sodium channel protein (neuronal and cardiac isoforms) (Nav)

Voltage-gated sodium channels, particularly on neurons and cardiac myocytes, are the principal molecular targets of local anesthetic drugs. These transmembrane ion channels regulate the initiation and propagation of action potentials in excitable tissues. Local anesthetics (e.g., lidocaine, bupivacaine) are amphipathic molecules that cross the cell membrane and bind to the cytoplasmic portion of the sodium channel, especially when the channel is in the open or inactivated states. This binding blocks sodium influx, preventing neuronal depolarization and conduction of pain signals[1][2][3][4][5][7][8]. Local anesthetics can be classified as amino amides (e.g., lidocaine, bupivacaine, ropivacaine) or amino esters (e.g., procaine, tetracaine, benzocaine) based on chemical structure[2][3][6]. Their clinical effects include loss of sensation, differential nerve blockade (sensory > motor), and, at high doses or accidental systemic administration, cardiac and CNS toxicity[1][2][7]. The voltage-gated sodium channel serves as the prototypical target for these drugs in both pain management and arrhythmia therapy.

Other names

Sodium channel (common)Voltage-gated sodium channel (common)Nav channel (common abbreviation)Sodium ion channelVGSC (Voltage-Gated Sodium Channel)Na+ channel

Reversible blockade of voltage-gated sodium (Na+) channels via binding to the cytoplasmic side of the channel [α-subunit][1][2][3][5][7][8]. Inhibition of sodium ion influx, preventing generation and propagation of action potentials (use-dependent or state-dependent)[1][5][7]. Stabilization of inactivated channel state, resulting in cessation of neural transmission[1][5][7]. Selective blockade of rapidly depolarizing fibers (sensory, autonomic; motor/large fibers at higher doses)[1][2][8].