Sodium channel protein (neuronal subtype; e.g., voltage-gated sodium channel)

Sodium channels are transmembrane proteins responsible for the rapid influx of sodium ions that initiates action potentials in excitable cells, including neurons and cardiac myocytes. Voltage-gated sodium channels are critical for electrical signaling in both the central and peripheral nervous system. Many drugs, including tricyclic antidepressants such as clomipramine and tetracyclic antidepressants such as maprotiline, exert part of their toxicity and side effects through blockade of these channels. Inhibition of neuronal sodium channels reduces neuronal firing but can, in overdose or with drug interactions, lead to severe cardiac and CNS side effects including arrhythmias, seizures, and death. These channels are targeted both therapeutically (for anesthesia, antiarrhythmics, some anticonvulsants) and as unintended adverse effect sites for certain antidepressants and other medications.

Other names

voltage-gated sodium channelneuronal sodium channelNav channelsodium ion channel

Inhibition (blockade) of voltage-gated sodium channels, reducing neuronal excitability and action potential generation