A Comparison of the Effects of Chlorhexidine and Sodium Bicarbonate Mouthwashes on COVID 19–Related Symptoms

Background: Some studies have reported that mouthwashes can decrease the viral load in the mouth, but there is not much information about the effectiveness of mouthwashes on coronavirus disease 2019 (COVID‑19). This study was conducted to compare the impact of using two types of mouthwash, chlorhexidine and sodium bicarbonate, on COVID‑19 symptoms and infection. Materials and Methods: The present three‑group, double‑blind clinical trial examined 116 operating room nurses and anesthesia personnel of certain hospitals of Isfahan University of Medical Sciences, Isfahan, Iran. The participants were randomly assigned to three groups: intervention group 1 (chlorhexidine mouthwash), intervention group 2 (sodium bicarbonate mouthwash), and the control group (placebo). Mouthwash was used twice a day (morning and night) for 2 weeks. The participants were monitored in terms of COVID‑19–related symptoms for 4 weeks, from the first day of mouthwash use. Results: Fisher’s exact test indicated a significant difference between the chlorhexidine and control groups in terms of the onset of COVID‑19–related symptoms (p = 0.02). There was no significant difference in the symptoms of COVID‑19 between the groups, but the groups were significantly different in terms of all symptoms at a 4‑week interval (p = 0.04). Furthermore, headache was less observed in the chlorhexidine (p = 0.007) and sodium bicarbonate (p = 0.03) groups compared to the control group. Conclusions: The use of 0.2% chlorhexidine mouthwash can decrease the onset of COVID‑19–related symptoms in health‑care workers. In addition, this mouthwash can partially reduce the symptoms of this disease in comparison to the control and sodium bicarbonate groups.