Effect of low-dose, long-term roxithromycin on airway inflammation and remodeling of stable noncystic fibrosis bronchiectasis

Bronchiectasis in renal transplant patients: a cross-sectional study

BACKGROUND

Bronchiectasis is a chronic airway disease characterized by permanent and irreversible abnormal dilatation of bronchi. Several studies have reported the development of bronchiectasis after renal transplantation (RT), but no prospective study specifically assessed bronchiectasis in this population. This study aimed to compare features of patients with bronchiectasis associated with RT to those with idiopathic bronchiectasis.

METHODS

Nineteen patients with bronchiectasis associated with RT (RT-B group) and 23 patients with idiopathic bronchiectasis (IB group) were prospectively included in this monocentric cross-sectional study. All patients underwent clinical, functional, laboratory, and CT scan assessments. Sputum was collected from 25 patients (n = 11 with RT-B and n = 14 with IB) and airway microbiota was analyzed using an extended microbiological culture.

RESULTS

Dyspnea (≥ 2 on mMRC scale), number of exacerbations, pulmonary function tests, total bronchiectasis score, severity and prognosis scores (FACED and E-FACED), and quality of life scores (SGRQ and MOS SF-36) were similar in the RT-B and IB groups. By contrast, chronic cough was less frequent in the RT-B group than in the IB group (68% vs. 96%, p = 0.03). The prevalence and diversity of the airway microbiota in sputum were similar in the two groups.

CONCLUSION

Clinical, functional, thoracic CT scan, and microbiological characteristics of bronchiectasis are overall similar in patients with IB and RT-B. These results highlight that in RT patients, chronic respiratory symptoms and/or airway infections should lead to consider the diagnosis of bronchiectasis. Further studies are required to better characterize the pathophysiology of RT-B including airway microbiota, its incidence, and impact on therapeutic management.

The effect of azithromycin on sputum inflammatory markers in bronchiectasis

BACKGROUND

Long term macrolide treatment has been found beneficial in bronchiectasis (BE) -pathogical bronchial dilatation- possibly due to a combined anti-bacterial and immunomodulatory effect. The exact mechanism of inflammatory response is unknown. Here, we investigated the effect of maintenance macrolide treatment on the inflammatory response in BE. In addition, we assessed the inflammatory profile in BE in relation to disease severity.

METHODS

During the BAT randomized controlled trial (investigating the effect of 1 year of azithromycin (AZM) in 83 BE patients), data on BE severity, lung function and sputum microbiology was collected. For the current study, a wide range of inflammatory markers were analysed in 3- monthly sputum samples in all participants.

RESULTS

At baseline, marked neutrophilic but also eosinophilic inflammation was present in both groups, which remained stable throughout the study and was not affected by AZM treatment. Significant upregulation of pro-inflammatory markers correlated with FEV₁ < 50% (TNFα, ECP, IL-21, IL-1, p = 0.01- 0.05), H. influenzae (HI) colonization (MPO, ECP, MIP-1, TNFα, IL-21, Il-8, IL-1, IL-1α, p < 0.001 - 0.04) and number of exacerbations (MPO, ECP, VEGF, MMP-9, p = 0.003 - 0.01). Surprisingly, colonization with P. aeruginosa (PA) was found to correlate with an attenuated inflammatory response compared to non-PA colonized. In placebo-treated patients, presence of an infectious exacerbation was reflected by a significant excessive increase in inflammation as compared to a non-significant upregulation in the AZM-treated patients.

CONCLUSION

One year of AZM treatment did not result in attenuation of the inflammatory response in BE. Increasing disease severity and the presence of an exacerbation were reflected by upregulation of pro-inflammatory markers.

Immunomodulatory Effects of Macrolides Considering Evidence from Human and Veterinary Medicine

Macrolide antimicrobial agents have been in clinical use for more than 60 years in both human and veterinary medicine. The discovery of the non-antimicrobial properties of macrolides and the effect of immunomodulation of the inflammatory response has benefited patients with chronic airway diseases and impacted morbidity and mortality. This review examines the evidence of antimicrobial and non-antimicrobial properties of macrolides in human and veterinary medicine with a focus toward veterinary macrolides but including important and relevant evidence from the human literature. The complete story for these complex and important molecules is continuing to be written.

Immunomodulation by Tetracyclines in the Critically Ill: An Emerging Treatment Option?

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2022. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2022 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Roxithromycin attenuates bleomycin-induced pulmonary fibrosis by targeting senescent cells

Idiopathic pulmonary fibrosis (IPF) is an aging-associated disease with a poor prognosis. Emerging evidence has revealed that targeting senescent cells may be a potential treatment for IPF. In this study, we aimed to explore whether roxithromycin (RXM) can improve lung fibrosis by targeting senescent cells. First, we confirmed the ability of RXM to selectively kill senescent cells by inducing apoptosis and inhibiting the expression of senescence-associated secretory phenotype (SASP) factors, suggesting the potential role of RXM as a "senolytic" and "senomorphic" drug. Next, we observed that TGF-β- and senescent cell-induced lung fibroblast activation was inhibited by RXM treatment, which prompted us to further investigate its effect in vivo. In a mouse model of bleomycin (BLM)-induced pulmonary fibrosis, RXM was shown to attenuate lung injury, inflammation, and fibrosis. Furthermore, the senescent phenotype of lung tissues induced by BLM was significantly diminished after RXM administration, indicating the potential of RXM as an antifibrotic and antisenescent agent. Interestingly, NADPH oxidase 4 (NOX4), implicated in lung fibrosis and cell senescence, was shown to be inhibited by RXM treatments. The antifibroblast activation and antisenescent effects of RXM were abolished in NOX4 knockdown cells, demonstrating that RXM may ameliorate BLM-induced pulmonary fibrosis by targeting senescent cells mediated by the NOX4 pathway. Collectively, these data demonstrated that RXM may be a potential clinical agent for IPF and further supported the notion that targeting cellular senescence is a promising treatment for progressive age-related disease.

The immunomodulatory effects of macrolide antibiotics in respiratory disease

Macrolide antibiotics are well known for their antibacterial properties, but extensive research in the context of inflammatory lung disease has revealed that they also have powerful immunomodulatory properties. It has been demonstrated that these drugs are therapeutically beneficial in various lung diseases, with evidence they significantly reduce exacerbations in patients with COPD, asthma, bronchiectasis and cystic fibrosis. The efficacy demonstrated in patients infected with macrolide tolerant organisms such as Pseudomonas aeruginosa supports the concept that their efficacy is at least partly related to immunomodulatory rather than antibacterial effects. Inconsistent data and an incomplete understanding of their mechanisms of action hampers the use of macrolide antibiotics as immunomodulatory therapies. Macrolides recently demonstrated no clinically relevant immunomodulatory effects in the context of COVID-19 infection. This review provides an overview of macrolide antibiotics and discusses their immunomodulatory effects and mechanisms of action in the context of inflammatory lung disease.

Expert recommendations on the role of macrolides in chronic respiratory diseases

Background:

India contributes to 32% of the total global disability-adjusted life years, due to chronic respiratory diseases. This has led to a high rate of health loss from these diseases. Antibiotics are commonly used in the management of respiratory disorders. With excellent tissue penetration, prolonged tissue persistence, and favorable side effect profile, macrolides are one of the best treatment options being recommended for respiratory, urogenital, dermal, and other bacterial infections. Still, there is a lack of clinical trial data on the use of macrolides in the management of respiratory chronic disease, and hence, there is a need for clinical guidance on their use in Indian setting.

Methods:

A systematic review of the literature was conducted on PubMed, Cochrane database, and Google Scholar. Existing guidelines, meta-analyses, systematic reviews, randomized controlled trials (RCTs), non-RCTs, landmark studies, and key-cited articles were selected. Recommendations were based on available evidence and expert panel's logical empiricism and consensus.

Results and Discussion:

This article discusses evidence-based and clinical practice based management of chronic respiratory conditions including chronic obstructive pulmonary disease, asthma, bronchiectasis, diffusive panbronchiolitis, and organizing pneumonia. The authors reviewed different respiratory conditions, role of macrolides in their management, adverse events and antimicrobial resistance associated with macrolides, evidence review of various clinical trials, guideline recommendations, and clinical recommendations.

Erythromycin Suppresses the Cigarette Smoke Extract-Exposed Dendritic Cell-Mediated Polarization of CD4+ T Cells into Th17 Cells

Cigarette smoke is a major effector of chronic obstructive pulmonary disease (COPD), and Th17 cells and dendritic cells (DCs) involve in the pathogenesis of COPD. Previous studies have demonstrated the anti-inflammatory effects of macrolides. However, the effects of macrolides on the cigarette smoke extract- (CSE-) induced immune response are unclear. Accordingly, in this study, we evaluated the effects of erythromycin (EM) on CSE-exposed DCs polarizing naïve CD4+ T cells into Th17 cells. DCs were generated from bone marrow-derived mononuclear cells isolated from male BALB/c mice and divided into five groups: control DC group, CSE-exposed DC group, CD40-antibody-blocked CSE-exposed DC group, and EM-treated CSE-exposed DC group. The function of polarizing CD4+ T cells into Th17 cells induced by all four groups of DCs was assayed based on the mixed lymphocyte reaction (MLR) of naïve CD4+ T cells. CD40 expression in DCs in the CSE-exposed group increased significantly compared with that in the control group (P < 0.05). The Th17 cells in the CSE-exposed DC/MLR group increased significantly compared with those in the control DC/MLR group (P < 0.05). Moreover, Th17 cells in the CD40-blocked CSE-exposed DC/MLR group and EM-treated CSE-exposed DC/MLR group were reduced compared with those in the CSE-exposed DC/MLR group (P < 0.05). Thus, these findings suggested that EM suppressed the CSE-exposed DC-mediated polarization of CD4+ T cells into Th17 cells and that this effect may be mediated through inhibition of the CD40/CD40L pathway.

A systematic review of pharmacotherapeutic clinical trial end-points for bronchiectasis in adults

Bronchiectasis is an increasing clinical problem, but multiple recent clinical trials have failed to reach their primary end-point. Difficulties in achieving “positive” bronchiectasis trials is reflected in a lack of agreement from trialists and regulators on what are the optimal end-points.

To evaluate the use of end-points in bronchiectasis trials, we conducted a systematic review of published bronchiectasis trials from 2008 to 2018 and extracted end-points used, definitions, methods of analysis and responsiveness.

Our analysis shows that quality of life and exacerbation end-points are most frequently used. Trials using exacerbation end-points have been characterised by varying definitions, multiple methods of analysis and durations of follow-up. There are multiple quality of life tools for bronchiectasis (Quality of Life – Bronchiectasis questionnaire, St George's Respiratory Questionnaire, etc.). The majority of studies measure lung function (e.g. forced expiratory volume in 1 s), but this is shown to be nonresponsive to the majority of interventions. Microbiology end-points frequently show statistically significant differences in phase 2 antibiotic studies but their correlation with clinical end-points is unknown.

This systematic review demonstrates a need for guidance to standardise definitions and design features to improve reproducibility and increase the likelihood of demonstrating statistically significant benefits with new therapies.

There is an urgent need to standardise clinical trial end-points in bronchiectasis. This systematic review shows the diversity of end-points used in bronchiectasis and suggests approaches that may improve the success rate and reproducibility of trials.http://ow.ly/d4HR30nvvS3

Challenges of diagnosing and managing bronchiectasis in resource-limited settings: a case study

Bronchiectasis, once an orphan disease is now gaining renewed attention as a significant cause of morbidity and mortality. It is a morphologic term used to describe abnormal, irreversibly dilated and thick-walled bronchi, with many etiologies. The management of bronchiectasis can be challenging because its pathogenetic mechanisms is still evolving. Its diagnosis and management is particularly more demanding especially in resource-limited settings like Nigeria because of delayed diagnosis and improper management with devastating consequences, hence this case study.

Azithromycin or erythromycin? Macrolides for non-cystic fibrosis bronchiectasis in adults: A systematic review and adjusted indirect treatment comparison

Non-cystic fibrosis (non-CF) bronchiectasis is a condition characterized by an airway inflammatory response to bacterial pathogens. Frequent exacerbations have a major influence on the quality of life. Macrolide antibiotics have not only antibacterial but also immune-regulation effects. It is proved that macrolides have a benefit in preventing exacerbations. However, it is still uncertain whether azithromycin or erythromycin is more effective and safe. The purpose of this study was to answer the following question: Which kind of macrolide antibiotic is more effective and safe in preventing non-CF bronchiectasis exacerbation? We conducted a systematic review to identify randomized clinical trials published up to May 2017 that reported on macrolides for non-CF bronchiectasis and an adjusted indirect treatment comparison (AITC) between macrolides to evaluate their efficacy and safety. The direct comparison meta-analysis found that macrolides decreased the rate of exacerbation of non-CF bronchiectasis (risk ratio (RR) = 0.45; 95% confidence interval (CI) 0.36–0.55) with heterogeneity (I² = 63.7%, p = 0.064). The AITC showed that azithromycin had a significantly lower bronchiectasis exacerbation rate than erythromycin (RR = 0.35; 95% CI: 0.403–0.947). Azithromycin increased the risk of diarrhea and abnormal pain. This meta-analysis suggested that long-term treatment with macrolides significantly reduced the incidence of non-CF bronchiectasis exacerbation. Moreover, azithromycin is more efficient than roxithromycin and erythromycin in preventing exacerbation.

Macrolide antibiotics for bronchiectasis

BACKGROUND

Bronchiectasis is a chronic respiratory disease characterised by abnormal and irreversible dilatation and distortion of the smaller airways. Bacterial colonisation of the damaged airways leads to chronic cough and sputum production, often with breathlessness and further structural damage to the airways. Long-term macrolide antibiotic therapy may suppress bacterial infection and reduce inflammation, leading to fewer exacerbations, fewer symptoms, improved lung function, and improved quality of life. Further evidence is required on the efficacy of macrolides in terms of specific bacterial eradication and the extent of antibiotic resistance.

OBJECTIVES

To determine the impact of macrolide antibiotics in the treatment of adults and children with bronchiectasis.

SEARCH METHODS

We identified trials from the Cochrane Airways Trials Register, which contains studies identified through multiple electronic searches and handsearches of other sources. We also searched trial registries and reference lists of primary studies. We conducted all searches on 18 January 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least four weeks' duration that compared macrolide antibiotics with placebo or no intervention for the long-term management of stable bronchiectasis in adults or children with a diagnosis of bronchiectasis by bronchography, plain film chest radiograph, or high-resolution computed tomography. We excluded studies in which participants had received continuous or high-dose antibiotics immediately before enrolment or before a diagnosis of cystic fibrosis, sarcoidosis, or allergic bronchopulmonary aspergillosis. Our primary outcomes were exacerbation, hospitalisation, and serious adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of 103 records. We independently screened the full text of 40 study reports and included 15 trials from 30 reports. Two review authors independently extracted outcome data and assessed risk of bias for each study. We analysed dichotomous data as odds ratios (ORs) and continuous data as mean differences (MDs) or standardised mean differences (SMDs). We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 14 parallel-group RCTs and one cross-over RCT with interventions lasting from 8 weeks to 24 months. Of 11 adult studies with 690 participants, six used azithromycin, four roxithromycin, and one erythromycin. Four studies with 190 children used either azithromycin, clarithromycin, erythromycin, or roxithromycin.We included nine adult studies in our comparison between macrolides and placebo and two in our comparison with no intervention. We included one study with children in our comparison between macrolides and placebo and one in our comparison with no intervention.In adults, macrolides reduced exacerbation frequency to a greater extent than placebo (OR 0.34, 95% confidence interval (CI) 0.22 to 0.54; 341 participants; three studies; I² = 65%; moderate-quality evidence). This translates to a number needed to treat for an additional beneficial outcome of 4 (95% CI 3 to 8). Data show no differences in exacerbation frequency between use of macrolides (OR 0.31, 95% CI 0.08 to 1.15; 43 participants; one study; moderate-quality evidence) and no intervention. Macrolides were also associated with a significantly better quality of life compared with placebo (MD -8.90, 95% CI -13.13 to -4.67; 68 participants; one study; moderate-quality evidence). We found no evidence of a reduction in hospitalisations (OR 0.56, 95% CI 0.19 to 1.62; 151 participants; two studies; I² = 0%; low-quality evidence), in the number of participants with serious adverse events, including pneumonia, respiratory and non-respiratory infections, haemoptysis, and gastroenteritis (OR 0.49, 95% CI 0.20 to 1.23; 326 participants; three studies; I² = 0%; low-quality evidence), or in the number experiencing adverse events (OR 0.83, 95% CI 0.51 to 1.35; 435 participants; five studies; I² = 28%) in adults with macrolides compared with placebo.In children, there were no differences in exacerbation frequency (OR 0.40, 95% CI 0.11 to 1.41; 89 children; one study; low-quality evidence); hospitalisations (OR 0.28, 95% CI 0.07 to 1.11; 89 children; one study; low-quality evidence), serious adverse events, defined within the study as exacerbations of bronchiectasis or investigations related to bronchiectasis (OR 0.43, 95% CI 0.17 to 1.05; 89 children; one study; low-quality evidence), or adverse events (OR 0.78, 95% CI 0.33 to 1.83; 89 children; one study), in those receiving macrolides compared to placebo. The same study reported an increase in macrolide-resistant bacteria (OR 7.13, 95% CI 2.13 to 23.79; 89 children; one study), an increase in resistance to Streptococcus pneumoniae (OR 13.20, 95% CI 1.61 to 108.19; 89 children; one study), and an increase in resistance to Staphylococcus aureus (OR 4.16, 95% CI 1.06 to 16.32; 89 children; one study) with macrolides compared with placebo. Quality of life was not reported in the studies with children.

AUTHORS' CONCLUSIONS

Long-term macrolide therapy may reduce the frequency of exacerbations and improve quality of life, although supporting evidence is derived mainly from studies of azithromycin, rather than other macrolides, and predominantly among adults rather than children. However, macrolides should be used with caution, as limited data indicate an associated increase in microbial resistance. Macrolides are associated with increased risk of cardiovascular death and other serious adverse events in other populations, and available data cannot exclude a similar risk among patients with bronchiectasis.

The Immunomodulatory Effects of Macrolides-A Systematic Review of the Underlying Mechanisms

Background

The mechanisms underlying the non-antimicrobial immunomodulatory properties of macrolides are not well understood.

Objectives

To systematically review the evidence for the immunomodulatory properties of macrolides in humans and to describe the underlying mechanism and extent of their influence on the innate and adaptive immune system.

Methods

A systematic literature search was done in MEDLINE using the OVID interface from 1946 to December 2016 according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Original articles investigating the influence of four macrolides (azithromycin, clarithromycin, erythromycin, and roxithromycin) on immunological markers in humans were included.

Results

We identified 22 randomized, controlled trials, 16 prospective cohort studies, and 8 case–control studies investigating 47 different immunological markers (186 measurements) in 1,834 participants. The most frequently reported outcomes were a decrease in the number of neutrophils, and the concentrations of neutrophil elastase, interleukin (IL)-8, IL-6, IL-1beta, tumor necrosis factor (TNF)-alpha, eosinophilic cationic protein, and matrix metalloproteinase 9. Inhibition of neutrophil function was reported more frequently than eosinophil function. A decrease in T helper (Th) 2 cells cytokines (IL-4, IL-5, IL-6) was reported more frequently than a decrease in Th1 cytokines (IL-2, INF-gamma).

Conclusion

Macrolides influence a broad range of immunological mechanisms resulting in immunomodulatory effects. To optimize the treatment of chronic inflammatory diseases by macrolides, further studies are necessary, particularly comparing different macrolides and dose effect relationships.

Neutrophil elastase in bronchiectasis

The role of neutrophil elastase (NE) is poorly understood in bronchiectasis because of the lack of preclinical data and so most of the assumptions made about NE inhibitor potential benefit is based on data from CF. In this context, NE seems to be a predictor of long-term clinical outcomes and a possible target of treatment. In order to better evaluate the role of NE in bronchiectasis, a systematic search of scientific evidence was performed.Two investigators independently performed the search on PubMed and included studies published up to May 15, 2017 according to predefined criteria. A final pool of 31 studies was included in the systematic review, with a total of 2679 patients. For each paper data of interest were extracted and reported in table.In this review sputum NE has proved useful as an inflammatory marker both in stable state bronchiectasis and during exacerbations and local or systemic antibiotic treatment. NE has also been associated with risk of exacerbation, time to next exacerbation and all-cause mortality. This study reviews also the role of NE as a specific target of treatment in bronchiectasis. Inhibition of NE is at a very early stage and future interventional studies should evaluate safety and efficacy for new molecules and formulations.

Bronchiectasis in the Last Five Years: New Developments

Bronchiectasis, a chronic lung disease characterised by cough and purulent sputum, recurrent infections, and airway damage, is associated with considerable morbidity and mortality. To date, treatment options have been limited to physiotherapy to clear sputum and antibiotics to treat acute infections. Over the last decade, there has been significant progress in understanding the epidemiology, pathophysiology, and microbiology of this disorder. Over the last five years, methods of assessing severity have been developed, the role of macrolide antibiotic therapy in reducing exacerbations cemented, and inhaled antibiotic therapies show promise in the treatment of chronic Pseudomonas aeruginosa infection. Novel therapies are currently undergoing Phase 1 and 2 trials. This review aims to address the major developments within the field of bronchiectasis over this time.

Consensus-Based Acne Classification System and Treatment Algorithm for Spain

Acne is a chronic inflammatory disease whose psychosocial effects can greatly impair quality of life. Various scales are used to classify the severity of acne, and several treatment algorithms are currently applied: no consensus on a common scale or treatment guidelines has been reached. A group of Spanish experts therefore met to identify a scale the majority could accept as the most appropriate for classifying severity and treating accordingly. The group chose the following classifications: comedonal acne, mild or moderate papulopustular acne, severe papulopustular acne, moderate nodular acne, and nodular-cystic acne (or acne tending to leave scars). Consensus was reached on first- and second-choice treatments for each type and on maintenance treatment. The experts also issued specific recommendations on antibiotic use (starting with mild or moderate papulopustular acne), always in combination with retinoids and/or benzoyl peroxide. The use of isotretinoin (starting at severe papulopustular or moderate nodular acne) was also covered.

Prolonged antibiotics for non-cystic fibrosis bronchiectasis in children and adults

BACKGROUND

The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator, preventing bacterial clearance and allowing persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics is believed to improve the condition of people with bronchiectasis, although no conclusive data show that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation, including prolonging antibiotic treatment with the goal of allowing the airway mucosa to heal.

OBJECTIVES

To determine the benefits of prolonged antibiotic therapy in the treatment of patients with bronchiectasis.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register and reference lists of identified articles. Searches were current as of February 2014.

SELECTION CRITERIA

Randomised trials examining the use of prolonged antibiotic therapy (for four or more weeks) in the treatment of bronchiectasis compared with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors to ask for missing information.

MAIN RESULTS

Eighteen trials met the inclusion criteria, randomly assigning a total of 1157 participants. Antibiotics were given for between four weeks and 83 weeks. Limited meta-analysis was possible because of the diversity of outcomes reported in these trials. Based on the number of participants with at least one exacerbation, the meta-analysis showed significant effects in favour of the intervention (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.19 to 0.52; P value < 0.00001), with events occurring in 271 per 1000 people in the intervention arm (95% CI 126 to 385) and in 546 per 1000 in the control population, based on evidence of moderate quality. A non-statistically significant reduction in hospitalisation favoured the use of prolonged antibiotics with a moderate quality grade of supporting evidence (37 per 1000 in the intervention arm (95% CI 13 to 96) and 87 per 1000 in control (OR 0.40, 95% CI 0.14 to 1.11; P value = 0.08). Drug resistance developed in 36 of 220 participants taking antibiotics compared with 10 of 211 participants given placebo or standard therapy (OR 3.48, 95% CI 1.20 to 10.07; P value = 0.02), translating to natural frequencies of 155 per 1000 in the intervention arm (95% CI 59 to 346) and 50 per 1000 in the control arm. The intervention was well tolerated with no overall significant difference in withdrawal between treatment and placebo groups (OR 0.91, 95% CI 0.56 to 1.49). Diarrhoea was commonly reported as an adverse event, particularly with an oral intervention.

AUTHORS' CONCLUSIONS

Available evidence shows benefit associated with use of prolonged antibiotics in the treatment of patients with bronchiectasis, at least halving the odds of exacerbation (with 275 fewer exacerbations per every 1000 people treated in the antibiotic arm compared with the control arm) and hospitalisation (50 fewer hospitalisations per 1000 people in the antibiotic arm compared with the control arm). However, the risk of emerging drug resistance is increased more than threefold. This review is limited by diversity of trials and by evidence of moderate to low quality. Further randomised controlled trials with adequate power and standardised end points are required.