Virucidal effect of povidone iodine on COVID-19 in the nasopharynx: A structured summary of a study protocol for an open-label randomized clinical trial
Authors: Hasan Mohammad Jahid , Rumi S. K. Nurul Fattah , Banu Sultana Sahana , Uddin A. K. M. Nasir , Islam Md Shahnoor , Arefin Mostafa Kamal 
Published: January 2021

Abstract
Objective
General: To assess the virucidal efficacy of povidone iodine (PVP-I) on COVID-19 virus located in the nasopharynx
Specific:
i. To evaluate the efficacy of povidone iodine (PVP-I) to removeCOVID-19 virus located in the nasopharynx
ii. To assess the adverse events of PVP-I

Trial design
This is a single-center, open-label randomized clinical trial with a 7-arm parallel-group design.

Participants
The study will be conducted at Dhaka Medical College Hospital, Dhaka, Bangladesh.

Inclusion criteria
All RT-PCR-confirmed COVID-19 cases aged between 15-90 years with symptoms for the past 4 days will be screened. Those who give informed consent, are willing to participate, and accept being randomized to any assigned group will also be considered for final inclusion.

Exclusion criteria
Patients with known sensitivity to PVP-I aqueous antiseptic solution or any of its listed excipients or previously diagnosed thyroid disease or who had a history of chronic renal failure: stage ≥3 by estimated glomerular filtration rate (eGFR) Modification of Diet in Renal Disease (MDRD) or had acute renal failure (KDIGO ≥stage 2: creatinine ≥2 times from the baseline) or patients who required invasive or noninvasive ventilation or planned within the next 6 hours were considered for exclusion. Moreover, lactating or pregnant women will also be restricted to include here.

Intervention and comparator
This RCT consist of seven arms:
Arm-1 (intervention group): will receive povidone iodine (PVP-I) nasal irrigation (NI) at a concentration of 0.4%
Arm-2 (intervention group): will receive PVP-I nasal irrigation at a concentration of 0.5%
Arm-3 (intervention group): will receive PVP-I nasal irrigation at a concentration of 0.6%.
Arm-4 (intervention group): will receive PVP-I nasal spray (NS) at a concentration of 0.5%.
Arm-5 (intervention group): will receive PVP-I nasal spray at a concentration of 0.6%.
Arm-6 (placebo comparator group): will receive distilled water through NI
Arm-7 (Placebo comparator group): will receive distilled water through NS
The intervention arms will be compared to the placebo comparator arms. Other supportive and routine care will be the same in both groups.

Main outcomes
The primary outcome is the proportion of cases that remain COVID-19 positive following the intervention. It will be assessed from 1 minutes to 15 minutes after the intervention. Any occurrence of adverse effects following the intervention will be documented as a secondary outcome.

Randomization
The assignment to the study (intervention) or control (comparator) group will be allocated in equal numbers through randomization using random number generation in Microsoft Excel by a statistician who is not involved in the trial. The allocation scheme will be made by an independent statistician using a sealed envelope. The participants will be allocated immediately after the eligibility assessment and consenting procedures.

Blinding (masking)
This is an open-label clinical trial, and no blinding or masking will be performed.

Numbers to be randomized (sample size)
A total of 189 confirmed cases of COVID-19 will be randomized into seven groups. In each arm, a total of 27 participants will be recruited.

Trial Status
The current trial protocol is Version 1.5 from September 10, 2020. Recruitment began September 30, 2020 and is anticipated to be completed, including data analysis by February 28, 2021.

Trial registration
The trial protocol has been registered in the ClinicalTrials.gov on September 16, 2020. NCT Identifier number: NCT04549376.

Full protocol
The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting the dissemination of this material, the familiar formatting has been eliminated; this letter serves as a summary of the key elements of the full protocol.