Virucidal Effect of Povidone Iodine on SARS-CoV-2 in Nasopharynx: An Open-label Randomized Clinical Trial

To assess the virucidal effect of povidone iodine (PVP-I) on severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) located in the nasopharynx and suitable dose-formulation for nasal application were the purpose of this clinical trial. This single-center, open-label randomized clinical trial with a 7-arm parallel-group design was conducted in Dhaka Medical College (DMC) Hospital. A total of 189 reverse transcription-polymerase chain reaction (RT-PCR)-confirmed SARS CoV-2 positive cases aged 12–90 years with symptoms was sequentially enrolled following randomization. Nasopharyngeal clearance of SARS-CoV-2 was tested against PVP-I nasal irrigation (NI) at diluted concentrations of 0.4%, 0.5% and 0.6%, and PVP-I nasal spray (NS) at diluted concentrations of 0.5% and 0.6%. All groups were compared to the corresponding controls (distilled water). Written informed consent was ensured before participation. All procedures were conducted in after ethical clearance from the Ethical Review Board and in accordance with the Declaration of Helsinki. Viral clearance in a repeat RT-PCR (qualitative) was the primary outcome, and occurrence of any adverse event following administration of testing drug was considered as the secondary outcome. Analysis was performed using SPSS (Version 26). All cases were randomized into seven groups and each group consists of 27-patient. Mean age of the cases 43.98 ± 12.67 years (SD). All strength of NI were effective in nasopharyngeal clearance compared to the control (0.4%, p = 0.006; 0.5%, p < 0.001; and 0.6%, p = 0.018). Similarly, all strength of the NS is also effective than control (0.5%, p =  < 0.001; and 0.6%, p ≤ 0.001). Highest nasopharyngeal clearance was observed in patients using 0.5% NI (n = 25, 92.6%, p = 0.018). Nasal irritation was the single most adverse event recorded in this trial and found in two patients using 0.4%, and 0.6% PVP-I NI, respectively. Both PVP-I NS and NI are effective for nasopharyngeal clearance in-vivo. However, further community trials are needed to repurpose these solutions as preventive agents against SARS-CoV2.