Polyvalent metal ions

Polyvalent metal ions are positively charged atoms with a valency of +2 or higher, including essential physiological ions like calcium (Ca2+), magnesium (Mg2+), and iron (Fe2+/3+), as well as toxic heavy metals like lead (Pb2+) and mercury (Hg2+). These ions are fundamental to biological life, serving as structural components in the skeletal system and as indispensable cofactors for enzymes involved in DNA replication, cellular respiration, and signal transduction (PubChem, 2024). In clinical pharmacology, polyvalent metal ions are the primary targets for chelation therapy, where drugs like deferoxamine or EDTA are used to sequester and remove excess or toxic metals from the body in conditions such as hemochromatosis or lead poisoning (StatPearls, 2023). Additionally, they are of significant concern due to their ability to interact with various oral medications; for instance, they can form insoluble precipitates with tetracyclines and fluoroquinolones, drastically reducing the bioavailability of these antibiotics (Merck Manual, 2023). Consequently, managing the intake and concentration of these ions is critical for maintaining metabolic homeostasis and ensuring the success of diverse therapeutic interventions.

Other names

Multivalent metal ionsPolyvalent cationsDivalent and trivalent metal ionsMetal cations

Chelation and complexation; chelating agents possess lone pairs of electrons that form coordinate covalent bonds with polyvalent metal ions, creating stable, water-soluble ring structures (chelates) that facilitate the excretion of toxic metals (StatPearls, 2023). Conversely, certain drugs like fluoroquinolones and tetracyclines form insoluble complexes with these ions in the gastrointestinal tract, which prevents the drug from being absorbed into the bloodstream (FDA, 2021).