A Review of Topical Povidone-iodine to Decrease Viral Load of COViD-19

Topical povidone-iodine (PVP-I) is currently being considered as a potential preventive measure against the spread of COVID-19. Diluted PVP-I solutions have been historically used in Asia to treat upper respiratory tract infections (URTIs) by decreasing the bacterial and viral load on oropharyngeal mucosa to decrease the transmission of diseases. Efficacy of gargling 0.23% PVP-I mouthwash in Japan demonstrated to be efficacious in lowering the prevalence of URTIs when compared with placebo. The 0.23% concentration was used in vitro on severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, which produced undetectable results after 30 seconds of exposure. Additionally, a recent study in 2020 proved the efficacy of PVP-I 0.45%-10% in reducing COVID-19 (SARS-CoV 2) viral load in vitro. Numerous clinical trials are being conducted to determine if there is a decrease in viral load, and thus transmission, when using oral or nasal topical PVP-I in COVID-19 patients. Because of the current lack of evidence for the use of PVP-I in vivo with COVID-19, it is recommended to await the clinical trial results before initiating this practice.