Sodium Channel Interactions

Voltage-gated sodium channels mediate the depolarising phase of the action potential: they switch between closed and open conformations according to the membrane voltage, and when open they let sodium pass down its electrochemical gradient, propagating the electrical signal along the nerve or muscle fibre. Drugs grouped here act at those channels; blocking them stops the action potential from being generated or propagated, which is how local anaesthetics abolish sensation in a region and how some anticonvulsants damp repetitive firing. The class name states the target but not the direction of effect.