About Permethrin Synthetic Pyrethroid , Antiparasitic Pediculicide, scabicide. Mechanism of Action of Permethrin Permethrin exerts its action by inhibiting sodium ion channel and delays depolarization. This will leads to (neuronal) paralysis of insects. Permethrin kills insects by strongly exciting their nervous systems. It makes the nervous system hypersensitive to stimuli from sense organs. Instead of sending a single impulse in response to a stimulus, Permethrin-exposed nerves send a series of impulses. This excitation occurs because Permethrin blocks the movement of sodium ions from outside to inside of the nerve cells. It is active against a broad range of pests including lice, ticks, fleas, mites, and other arthropods.