Benzonatate is a reversible voltage-gated sodium channel blocker.
1 It blocks Na
v1.7 currents in a concentration- and voltage-dependent manner (IC
50s = 5.9 and 1.4 μM at holding potentials of -100 and -70 mV, respectively) and inhibits action potential firing in catecholamine A differentiated (CAD) cells. Benzonatate also blocks 80% of Na
v1.3 currents in N1E-115 cells when used at a concentration of 100 μM.
In vivo, benzonatate (0.85 mg/min) reduces the frequency, but has no effect on the amplitude, of the cough reflex in anesthetized dogs.
2 Formulations containing benzonatate have been used as antitussive agents for the treatment of coughs.