Inhaled Dry Powder Antibiotics in Patients with Non-Cystic Fibrosis Bronchiectasis: Efficacy and Safety in a Real-Life Study

Efficacy and Safety of Dry Powder Antibiotics: A Narrative Review

The use of inhaled antibiotics was initially almost exclusively confined to patients with cystic fibrosis (CF). However, it has been extended in recent decades to patients with non-CF bronchiectasis or chronic obstructive pulmonary disease who present with chronic bronchial infection by potentially pathogenic microorganisms. Inhaled antibiotics reach high concentrations in the area of infection, which enhances their effect and enables their long-term administration to defeat the most resistant infections, while minimizing possible adverse effects. New formulations of inhaled dry powder antibiotics have been developed, providing, among other advantages, faster preparation and administration of the drug, as well as avoiding the requirement to clean nebulization equipment. In this review, we analyze the advantages and disadvantages of the different types of devices that allow the inhalation of antibiotics, especially dry powder inhalers. We describe their general characteristics, the different inhalers on the market and the proper way to use them. We analyze the factors that influence the way in which the dry powder drug reaches the lower airways, as well as aspects of microbiological effectiveness and risks of resistance development. We review the scientific evidence on the use of colistin and tobramycin with this type of device, both in patients with CF and with non-CF bronchiectasis. Finally, we discuss the literature on the development of new dry powder antibiotics.

Inhaled Colistimethate Sodium in the Management of Patients with Bronchiectasis Infected by Pseudomonas aeruginosa: A Narrative Review of Current Evidence

International guidelines on the treatment of bronchiectasis indicate that the use of inhaled antibiotics is effective, especially in symptomatic chronic bronchial infection (CBI) due to Pseudomonas aeruginosa (PA). To date, however, no such treatment has been approved by regulatory agencies. Of the inhaled antibiotics on the market, colistimethate sodium (colistin) is one of the most used in many countries, either in its nebulized presentation or as dry powder. Among the characteristics of this antibiotic, it is worth noting that its main target is the lipopolysaccharide in the outer membrane of the cell wall of gram-negative bacteria and that it has a low rate of resistance to PA (<1%). Most observational studies have shown that the use of colistin in patients with bronchiectasis and CBI due to PA results in a decrease in both the number and severity of exacerbations, an improvement in quality of life, a decrease in sputum volume and purulence, and a high rate of PA eradication, although there are no clear differences with respect to other inhaled antibiotics. However, the lack of randomized clinical trials (RCT) with positive results for its main variable (exacerbations) in an intention-to-treat analysis has prevented its approval by regulatory agencies as a formal indication for use in bronchiectasis. The PROMIS program, made up of two RCT with identical methodology, is currently underway. The first of these RCT (already concluded) has demonstrated a clearly positive effect on the group randomized to colistin in its main variable (number of annual exacerbations), while the results of the second are still pending. This review presents exhaustive information on the pharmacological and microbiological characteristics of colistin, the results of the studies carried out to date, and the future challenges associated with this treatment.

Inhaled Antibiotics in Non-cystic Fibrosis Bronchiectasis (NCFB): A Systematic Review of Efficacy and Limitations in Adult Patients

Non-cystic fibrosis bronchiectasis has recently been under the spotlight due to a better detection rate with advanced imaging techniques. Recurrent infections in such patients are the main cause of their deterioration. This invariably leads to a catastrophic wheel of decline in lung function, reinfection, and repeated hospital consultations. The main goal of their management is based on the principles of prevention and vigorous treatment of recurrent infections. This review aimed to gather recent therapeutic options for inhaled antibacterial use in such patients and compare them for their properties of safety and efficacy. Studies done in the last 10 years on adult patients were gathered using the Medical Subject Headings (MeSH) strategy and later sorted using the inclusion/exclusion criteria. Research engines used include Google Scholar, PubMed, and the Saudi Digital Library. Out of the 31,739 articles identified initially, 1362 were screened. The final eight selected papers were assessed for quality by using the quality assessment checklist, the Cochrane bias assessment tool, the Scale for the Assessment of Narrative Review Articles (SANRA) tools and cross-examined by co-authors. We concluded that the use of inhaled antibiotics as an adjuvant and follow-up treatment option is associated with better short and long-term prognoses in patients. They lead to lesser systemic side effects than the oral and intravenous varieties available on the market. However, the establishment of a hierarchy among the subgroups remains a grey area that needs further research.

Safety and Efficacy of Devices Delivering Inhaled Antibiotics among Adults with Non-Cystic Fibrosis Bronchiectasis: A Systematic Review and a Network Meta-Analysis

It remains unknown whether the type of aerosol generating device is affecting efficacy and safety among non-cystic fibrosis bronchiectasis (NCFB) adults. The proposal of this network meta-analysis (NMA) is to evaluate effectiveness and safety of inhaled antibiotics administered via dry powder inhaler (DPI) and via nebulizers (SVN) among adult patients with NCFB. Inclusion criteria were randomized-controlled trials, adults (≥18 years) with NCFB, and inhaled antibiotics administered via DPI as intervention. Search strategy was performed in PubMed, Web of Science, and Cochrane Library from 2000 to 2019. Sixteen trials (2870 patients) were included. Three trials (all ciprofloxacin) used DPIs and thirteen used SVN (three ciprofloxacin). Both DPI and SVN devices achieved similar safety outcomes (adverse events, antibiotic discontinuation, severe adverse events, and bronchospasm). Administration of ciprofloxacin via DPI significantly improved time to first exacerbation (87 days, 95% CI 34.3–139.7) and quality of life (MD −7.52; 95% CI −13.06 to −1.98) when compared with via SVN. No other significant differences were documented in clinical efficacy (at least one exacerbation, FEV₁% predicted) and microbiologic response (bacterial eradication, emergence of new potential pathogens, and emergence of antimicrobial resistance) when comparing devices. Our NMA documented that time to first exacerbation and quality of life, were more favorable for DPIs. Decisions on the choice of devices should incorporate these findings plus other criteria, such as simplicity, costs or maintenance requirements.