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Sodium channel blocker
Synonym(s)
DefinitionThis section has been translated automatically.
Sodium channel blockers are a group of drugs whose mechanism of action consists in the antagonization of voltage-dependent or non-voltage-dependent sodium channels.
Voltage-dependent sodium channels initiate action potentials by intracellularly directed depolarization currents in neurons and cardiomyocytes. Accordingly, NAV antagonists inhibit neuronal or cardiac excitability (see also ion channels).
ClassificationThis section has been translated automatically.
The following substance groups function by blocking voltage-dependent Na+ channels:
Local anaesthetics are substances that reversibly block the initiation and transmission of action potentials in nerve fibres by blocking voltage-dependent Na+ channels. They are divided according to their chemical structure into:
Local anaesthetics of the ester type
Amide-type local anaesthetics
Anticonvulsants (antiepileptic drugs) whose essential mechanism of action is seen in a blockage of the sodium channel (e.g. carbamazepine, felbamate, lamotrigine, oxcarbazepine, phenytoin or topiramate).
Antiarrhythmics (Class I antiarrhythmics): Their main representatives include ajmaline, quinidine, flecainide, lidocaine, prajmaline and propafenone. They inhibit the rapid influx of sodium (by directly blocking the voltage-dependent Na+ channels) of phase I of the action potential in the working myocardium. These can be divided according to their binding behaviour into:
Fast-Drugs: They quickly release themselves from the Na+ channel. These include lidocaine and tocainide.
Slow-Drugs: They are released from the Na+-channel with a significant delay (all other antiarrhythmic drugs).