Nasopharyngeal povidone iodine application found to reduce COVID-19 load

In individuals suffering from mild to moderate coronavirus disease, nasopharyngeal decolonization may decrease the carriage of infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

A randomized clinical trial was carried out to assess whether the nasopharyngeal application of povidone-iodine could lower the viral load of adults suffering from nonsevere coronavirus disease 2019 (COVID-19) symptoms.

The trial recruited individuals that were tested highly positive for SARS-CoV-2 ribonucleic acid (RNA) by reverse transcription-polymerase chain reaction (RT-PCR) in nasopharyngeal swabs within the prior 48 hours. Subjects underwent a further nasopharyngeal swab for viral quantification at baseline prior to being randomly allocated to either an intervention arm (n = 12) or a control arm (no intervention, n = 12). The intervention arm was given four successive mouthwashes and gargles with 25 ml of 1% aqueous povidone-iodine solution each.

After this, one 2.5-ml nasal pulverization of the similar solution into each nostril was carried out utilizing an intranasal mucosal atomization device that was connected to a 5-ml syringe while sniffing and one application on each nasal mucosa of a dab of 10% povidone-iodine ointment. This was subsequently followed by nostril massage to aid ointment spread. Participants carried out the following sessions four times a day for five days.

To examine the efficacy (viral quantification) and safety of the decolonization, the subjects were followed-up on day 1 and then every two days until the 7th day. About >95% of the nasopharyngeal swabs were procured at least three hours after the last povidone-iodine application for quantifying viral RNA, and viral titer. With the aid of a linear mixed model for repeated measures, the alterations in viral load over time were evaluated between the groups.

All participants but one had negative viral titer by the third day. The usage of povidone-iodine had no influence on alterations of viral RNA quantification over time. The mean relative difference in viral titers (between first day and baseline) was found to be higher in the intervention arm vs. control arm (75% vs 32%). All povidone iodine-exposed subjects witnessed obnoxious nasal tingling but completed the assessment.

The rise in thyroid-stimulating hormone (median [interquartile range], 3.4 mIU/L vs 2.1 mIU/L at baseline) was noted in all participants after five days of povidone-iodine exposure, considerably exceeding the upper normal value in five subjects, with a return to baseline values seven to 12 days afterward. No alteration in creatinine or thyroid hormone (T4, T3) levels was noted. The thyroid dysfunction was found to occur in 42% of the subjects exposed to povidone-iodine, with spontaneous resolution upon therapy discontinuation.

The use of povidone-iodine may minimize the carriage of infectious SARS-CoV-2 in individuals suffering from mild to moderate coronavirus infection.