From Ion Flux to Pain Chronification: Sodium, Calcium, and TRP Channel Crosstalk as Therapeutic Targets

Chronic pain is a persistent sensory and emotional condition that extends beyond tissue healing and imposes a substantial clinical and socioeconomic burden worldwide. It includes nociplastic, neuropathic, and inflammatory pain states that all lead to maladaptive peripheral and central sensitization, making diagnosis more challenging while reducing the overall effectiveness of long-term treatment. Many patients experience inadequate pain relief with currently available analgesic drugs, including nonsteroidal anti-inflammatory medications, opioids, antidepressants, and anticonvulsants, owing to their limited efficacy, development of tolerance, and severe adverse effects. There is increasing evidence that, ion-channel modulation serves an important role in the onset and maintenance of chronic pain. Membrane excitability, neurotransmitter release, and synaptic plasticity controlled by voltage-gated sodium (Nav), voltage-gated calcium (Cav), and transient receptor potential (TRP) channels are all considered essential components of nociceptive signaling. Pathological remodeling of Na+ channels (Nav1.7, Nav1.8, Nav1.9, and Nav1.3) has been associated with ectopic firing and nociceptor hyperexcitability in a variety of preclinical and clinical investigations, whereas Ca+ channels (Cav2.2, Cav3.x, and α2δ subunits) have been linked to enhanced central sensitization and calcium-dependent transmission. Interactions among these channel families form feed-forward mechanisms that sustain pain signaling across peripheral and central circuits. This review highlights Nav, Cav, and TRP channel crosstalk and their differential involvement across pain phenotypes and disease stages, while discussing emerging therapeutic strategies, including isoform-selective and state-dependent modulators, peripheral restriction, combination therapies, and targeted delivery systems. Integrating these mechanistic insights with ion-channel profiling and phenotype- and tissue-selective modulation may enable more rational target selection, improve therapeutic precision, and facilitate the development of selective, durable, mechanism-based treatments for chronic pain.