Other ion channels

The term Other ion channels refers to a heterogeneous grouping of transmembrane proteins that facilitate the selective movement of ions across biological membranes but do not fall into the primary classifications of voltage-gated or major ligand-gated ion channels (Wickenden, 2002; https://doi.org/10.1038/nrd893). This broad category encompasses several distinct and physiologically vital families, including Transient Receptor Potential (TRP) channels, Acid-Sensing Ion Channels (ASICs), Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels, and various Chloride Channels (ClC) (Alexander et al., 2023; https://doi.org/10.1111/bph.16205). These proteins are essential for diverse biological processes such as mechanotransduction, thermoreception, pH sensing, and the maintenance of osmotic balance. In clinical pharmacology, these channels are targeted for a wide range of indications; for instance, HCN channels are targeted by ivabradine to manage heart rate, while chloride channels are targeted by lubiprostone for chronic constipation (StatPearls, 2023; https://www.ncbi.nlm.nih.gov/books/NBK507783/). Because this is a non-specific classification rather than a single molecular entity, it is considered an incorrect designation for a specific therapeutic target. Developing drugs for these channels often requires high selectivity to avoid systemic toxicity, as many of these proteins are expressed in both the central nervous system and peripheral tissues.

Other names

Miscellaneous ion channelsNon-voltage-gated ion channelsUnclassified ion channelsAtypical ion channels

Drugs targeting these channels typically act as pore blockers, allosteric modulators, or gating stabilizers to either inhibit or enhance the flow of specific ions (such as chloride, sodium, or cations) across the cell membrane (Alexander et al., 2023; https://doi.org/10.1111/bph.16205).