Objective: The present study aimed to investigate the in vivo activity of nasal irrigation (NI) with saline, NI with povidone-iodine (PVP-I) 1%, NI with a mix of hypertonic alkaline and PVP-I 1% against Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2).
Design: This study was a prospective randomised clinical trial.
Setting: A multicenter study involving tertiary care centres.
Participants: The study included adult outpatients whose qualitative SARS-CoV-2 RT-PCR tests in nasopharyngeal swabs were positive. One hundred twenty patients were divided into four equal groups. Standard COVID-19 treatment was given to Group 1, NI containing saline was added to patients' treatment in Group 2, NI containing 1% PVP-I solution was added to patients' treatment in Group 3, and NI containing 1% PVP-I solution and the hypertonic alkaline solution was added to patients' treatment in Group 4.
Main outcome measures: On the first day of diagnosis (Day 0), nasopharyngeal swab samples were taken, on the third and fifth days the nasopharyngeal viral load (NVL) reduction in quantitative RT-PCR test was calculated.
Results: Between the zeroth to third days and zeroth to fifth days, the NVL reduction was significant in all groups (p < .05). In paired comparisons of groups, the NVL decrease in Group 4 in the first 3 days was significantly lower than all groups (p < .05). The NVL decrease in Groups 3 and 4 in the first 5 days were significantly lower than Group 1 (p < .05).
Conclusion: This study revealed that the use of NI of 1% PVP-I and the hypertonic alkaline solution mixture was more effective in reducing NVL.
Keywords: COVID-19; hypertonic alkaline solution; nasopharyngeal viral load; povidone-iodine.
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