Sodium channel protein (Voltage-gated sodium channel; alpha subunit)

Voltage-gated sodium channels are transmembrane ion channels responsible for the initiation and propagation of action potentials in excitable cells such as neurons and muscle. Local anesthetic drugs, such as lidocaine and bupivacaine, bind reversibly to the cytoplasmic portion of these channels in their open or inactivated states, blocking sodium influx and thus inhibiting action potential propagation. This leads to a loss of sensation in the innervated area. Local anesthetics show use-dependent (phasic) block, acting more strongly when neurons are firing rapidly. These agents display variable potency, onset, and duration of action depending on their lipophilicity, protein binding, and chemical structure. Systemic absorption or overdose can cause CNS and cardiac toxicity.

Other names

VGSCNa₋ channelvoltage-gated sodium channelsodium ion channel

Blockade of voltage-gated sodium channels leading to reversible inhibition of action potential generation and conduction in excitable tissues