A Cetylpyridinium Chloride Oral Rinse Reduces Salivary Viral Load in Randomized Controlled Trials

Evaluating the antiviral potential of commercially available mouthrinses on SARS-CoV-2 holds potential for reducing transmission, particularly as novel variants emerge. Because SARS-CoV-2 is transmitted primarily through salivary and respiratory secretions and aerosols, strategies to reduce salivary viral burden in an antigen-agnostic manner are attractive for mitigating spread in dental, otolaryngology, and orofacial surgery clinics where patients may need to unmask.

Patients (n = 128) with confirmed COVID-19-positive status within 10 days of symptom onset or positive test result were enrolled in a double-blind randomized controlled trial of Food and Drug Administration-approved mouthrinses containing active ingredients ethanol, hydrogen peroxide, povidone iodine, chlorhexidine gluconate, cetylpyridinium chloride (CPC), or saline. The CPC, ethanol, and sterile water rinses were followed in a second double-blind randomized controlled trial (n = 230). Participants provided a saliva sample before rinsing (baseline) and again at 30 and 60 min after rinse. Quantitative polymerase chain reaction was used to determine salivary SARS-CoV-2 viral load at all time points. An adjusted linear mixed-effect model was employed to compare viral load after rinsing relative to baseline.

The rinse containing CPC significantly reduced salivary SARS-CoV-2 viral load 30 min postrinse relative to baseline (P = .015), whereas no other rinse significantly affected viral load at 30 min after rinsing. At 60 min postrinsing, no group had a significant reduction in SARS-CoV-2 copy number relative to baseline, indicating a rebound in salivary viral load over a 1-hour window. Participants indicated a fair to good rinsing experience with the CPC product and high willingness to use oral rinses before and during dental and medical health care visits.

Our findings suggest that preprocedural oral rinsing could be implemented as a feasible, inexpensive approach to mitigate spread of SARS-CoV-2 and potentially other enveloped viruses for short periods, which is relevant to clinical procedures involving the nasal and oropharyngeal region.Knowledge Transfer Statement:Rinsing with a cetylpyridinium chloride-containing mouthrinse can significantly reduce salivary SARS-CoV-2 viral load for up to 30 min; patients are willing to use mouthrinses in medical and dental settings to limit transmission risk in clinics.