Efficacy of antiseptic mouthrinses against SARS-CoV-2: A prospective randomized placebo-controlled pilot study

ObjectivesCoronavirus-disease-19 (COVID-19) continues to affect millions of individuals worldwide. Antiviral activity of mouthrinses remains an important research area as the oral cavity is a site of SARS-CoV-2 initial replication. The aim of this study was to assess the effectiveness of three different mouthrinses in reducing the oral/oropharyngeal SARS-CoV-2 viral load.MethodsAdult patients, hospitalized with confirmed COVID-19 were recruited for the study. Oral/oropharyngeal baseline SARS-CoV-2 samples were collected and analyzed by Real-Time-PCR. Subsequently, patients were instructed to rinse with 1% hydrogen peroxide (H2O2), 0.12% chlorhexidine (CHX), 1% povidone‑iodine (PVP-I) or Sodium Chloride 0.9% (placebo). Viral loads were measured right after (T1), and at 45min (T2) from the rinse.ResultsIn the PVP-I 1% group, 5/8 (62.5%) patients at T1, and 3/8 (37.5%) patients at T2, SARS-CoV-2 was not detectable in the swab specimens. In the H2O2 1% group, 2/11 (18.2%) patients at T1, and 2/11 (18.2%) other patients at T2 showed no SARS-CoV-2 loads. One (12.5%) patient in the CHX 0.12% group showed SARS-CoV-2 negativity at T2. One (9.1%) patient at T1, and another (9.1%) patient at T2 showed no SARS-CoV-2 loads in the placebo group.ConclusionsOral SARS-CoV-2 loads were reduced at T1 in the PVP-I 1% and H2O2 1% groups.Clinical relevancePVP-I 1% was the most effective rinse especially in patients with low viral copy numbers at baseline.