Chlorhexidine oral rinse improves COPD symptoms

Patients with chronic obstructive pulmonary disease (COPD) seem to benefit from using chlorhexidine oral rinses twice daily as shown by the reduction in oral and sputum microbiota alpha diversity and by clinically significant improvements in COPD symptoms, according to a study presented at ID Week 2020.

On the other hand, “[c]hlorhexidine use did not result in decreased oral or sputum microbiota biomass or decreased systemic inflammation,” the researchers said.

A randomized, double-blind, placebo-controlled study was conducted for 8 weeks to examine the effects of twice-daily chlorhexidine oral rinses on 44 patients with COPD. Of the participants, 24 (mean age, 67.6 years; 8.3 percent female) were assigned to chlorhexidine and 20 (mean age, 68.3 years; 5.0 percent female) to placebo.

The researchers obtained baseline and post-treatment data to evaluate oral and sputum microbiota biomass and composition, systemic inflammation (C-reactive protein [CRP], fibrinogen, and white blood cell [WBC] count), and respiratory symptoms (ie, Breathlessness, Cough, and Sputum Scale [BCSS], St. George’s Respiratory Questionnaire [SGRQ], and acute exacerbation of COPD assessment).

Forty patients completed the study. No significant differences were noted in oral and sputum microbiota biomass between the two treatment groups in the primary analysis. [ID Week 2020, abstract 634]

Use of chlorhexidine resulted in a decrease in oral and sputum microbiota alpha diversity as compared with placebo (Shannon diversity index change [standard error], –0.349 [0.091] and –0.622 [0.169], respectively; p=0.001 for both).

Over the study period, no significant change was observed in CRP, fibrinogen, WBC count, or BCSS score between the two groups.

Moreover, chlorhexidine use was associated with a significant improvement in SGRQ score as compared to placebo (mean change, –4.7±8.0 vs 1.7±8.9; p=0.011; minimal clinically significant difference in SGRQ score, –4). Adverse events reported were few.

In a recent study, results showed that mouthwash containing chlorhexidine contributed to a major shift in the salivary microbiome, which led to more acidic conditions and lower nitrite availability in healthy individuals. Chlorhexidine significantly increased the abundance of Firmicutes and Proteobacteria and decreased the content of Bacteroidetes, TM7, SR1, and Fusobacteria. [Sci Rep 2020;105254]

“This shift was associated with a significant decrease in saliva pH and buffering capacity, accompanied by an increase in saliva lactate and glucose levels,” the authors said. “Lower saliva and plasma nitrite concentrations were found after using chlorhexidine, followed by a trend of increased systolic blood pressure.”

COPD is a progressive lung disease that has few available disease-modifying therapies. Acute exacerbations of COPD tend to increase morbidity and mortality and coincide with sputum and oral microbiota dysbiosis, according to the researchers of the current study.

“The oral microbiota also serves as the source of the lower airway microbiota. Chlorhexidine oral rinses are known to alter the oral microbiota,” they added.