Inhaled antibiotics can effectively kill bacteria and lessen exacerbations in people with stable non-cystic fibrosis bronchiectasis (NCFB), but they do not improve lung function or life quality, a review study found.
They also were unable to eradicate Pseudomonas aeruginosa, and could risk making this bacteria more resistant to treatment, its investigators wrote.
The study, “Inhaled antibiotics therapy for stable non-cystic fibrosis bronchiectasis: a meta-analysis,” was published in the journal Therapeutic Advances in Respiratory Disease.
Bronchiectasis is characterized by persistent dilation and damage to bronchi, which carry air through the lungs. Bacterial infections in the lungs may further exacerbate such damage.
Inhaled antibiotics are a possible way of treating bronchiectasis. However, unlike existing guidelines in people with cystic fibrosis, treatment of NCFB with inhaled antibiotics still lacks clinical consensus.
Researchers in China performed a meta-analysis — an assessment that pools results from multiple studies — on the use of inhaled antibiotics in NCFB. Specifically, they pooled data from 16 studies, which reported findings from 17 trials published between 1999 and 2019. A total of 2,748 people with NCFB were included in the analysis.
The scientists analyzed results according to various endpoints, or goals, such as the amount of bacteria in the lungs and quality of life metrics. Not all participants had data available for every goal.
Treatment with inhaled antibiotics significantly decreased the levels of bacteria in sputum. Additional analysis indicated that ciprofloxacin was more effective than other antibiotics — aminoglycosides, aztreonam, or colistin — in this regard.
However, inhaled antibiotics did not effectively lower sputum levels of P. aeruginosa, a bacteria that causes pneumonia and commonly infects people with bronchiectasis.
Treatment significantly decreased the risk of exacerbations or flares, and significantly prolonged the median time to the first recorded exacerbation.
Inhaled antibiotics did not significantly improve lung function, as measured by percent predicted forced expiratory volume. It also did not significantly alter health-related quality of life according to two questionnaires: quality of life-bronchiectasis and St. George’s respiratory questionnaire.
A concern with antibiotic use is that bacteria can become resistant to treatment, making the antibiotic ineffective. Multiple studies reported antibiotic resistance, and the risk of P. aeruginosa acquiring antibiotic resistance was significantly increased (by 88%) with inhaled treatment, the researchers wrote.
A safety analysis indicated that inhaled antibiotics were generally well tolerated, although their use was associated with an increased risk of dysgeusia (altered the sense of taste).
“Inhaled antibiotics therapy can effectively reduce the sputum bacterial load and the risk of acute attack and delay disease progression,” the researchers wrote. “However, treatment fails to increase the eradication rate of P. aeruginosa due to drug resistance during medication, nor has any effect on HRQoL [health-related quality of life].”
They stressed the importance of further research to develop guidelines on how best to use inhaled antibiotics to treat people with NCFB.
“Further large-scale, long-term clinical trials should be carried out on the basis of a sophisticated continuous study design with recognized antibiotics that can used be safely, in order to explore evidence-based optimum doses and regimes,” they added.