Pharmacokinetics and pharmacodynamics of chlorine dioxide

Chlorine dioxide (ClO2) is widely used as a drinking water disinfectant in many countries. Due to its antibiotic andantiviral capacity, it has aroused interest as a potential therapeutic agent with respect to the COVID-19 disease, AIDSand Influenza. As a result of this debate in scientific and governmental settings, it was deemed highly timely toprovide an up-to-date assessment of the pharmacokinetics and pharmacodynamics of ClO2. The main findingsindicate that, due to its high chemical reactivity, ClO2 is rapidly reduced in oral and gastric secretions, producingchlorite (ClO2⁻), which becomes the active agent responsible for its systemic actions. ClO2 also showed potential toact as an oxidant or antioxidant depending on the concentration. Of particular therapeutic interest are the findingsthat, at low concentrations, ClO2⁻ can protect erythrocytes from oxidative stress while inhibiting excessiveproduction of hypochlorous acid (HClO) mediated by myeloperoxidase (MPO), thus reversing the inflammatoryresponses and macrophage activation. Finally, taurine-chloramine represents the most relevant functional productformed under the influence of ClO2⁻, said molecule activates the erythroid nuclear factor 2 (Nrf2), (this transcriptionfactor regulates the inducible expression of numerous genes for detoxifying and antioxidant enzymes) , increases theexpression of heme-oxygenase (HO-1), protects cells from death caused by hydrogen peroxide (H2O2), improves theexpression and activities of antioxidant enzymes, such as superoxide dismutase, catalase and glutathioneperoxidase, and contributes to the resolution of the inflammatory process.