Voltage-gated sodium channel NaV1.8

Class

selective NaV1.8 sodium channel blocker; binds voltage-sensing domain 2 (VSD2), a site distinct from the channel pore and from local-anesthetic binding sites, stabilizing the channel's closed state; peripherally restricted, non-opioid

Pathway

selectively inhibits NaV1.8 (reported ≥31,000-fold selective over other NaV subtypes in vitro), a channel expressed on peripheral sensory/dorsal root ganglion neurons but not in the human brain or spinal cord, blocking transmission of pain signals to the CNS without central opioid-like effects; the major active metabolite M6-SUZ contributes weaker additional NaV1.8 inhibition (~3.7-fold less potent than parent)

NaV1.8 is a subtype of voltage-gated sodium channel found predominantly on peripheral sensory neurons, including the nociceptors that detect painful stimuli and the dorsal root ganglia through which their signals travel toward the spinal cord. Sodium channels of this family open in response to changes in the electrical charge across a neuron's membrane, allowing a rapid influx of sodium ions that generates the action potential, the electrical impulse by which nerve cells transmit information. NaV1.8 contributes to the rising phase of action potentials specifically in pain-sensing neurons, making it a plausible point of intervention for suppressing pain signals at their source rather than in the brain. This distinguishes it from opioid analgesics, which act on receptors within the central nervous system and carry risks of sedation, respiratory depression, and dependence. Because NaV1.8 is largely absent from the brain and spinal cord, blocking it selectively is expected to relieve pain signaling without producing the central effects associated with opioids. This mechanism is of broad interest across acute and chronic pain conditions, including postoperative pain and various forms of neuropathic pain, where reducing peripheral nerve excitability without systemic central nervous system exposure offers a distinct safety profile from existing analgesic classes.