WITHDRAWN: Inhaled bronchodilators for cystic fibrosis

Short-acting inhaled bronchodilators for cystic fibrosis

BACKGROUND

Respiratory disease is the main cause of morbidity and mortality in cystic fibrosis (CF), and many different therapies are used by people with CF in the management of respiratory problems. Bronchodilator therapy is used to relieve symptoms of shortness of breath and to open the airways to allow clearance of mucus. Despite the widespread use of inhaled bronchodilators in CF, there is little objective evidence of their efficacy. A Cochrane Review looking at both short- and long-acting inhaled bronchodilators for CF was withdrawn from the Cochrane Library in 2016. That review has been replaced by two separate Cochrane Reviews: one on long-acting inhaled bronchodilators for CF, and this review on short-acting inhaled bronchodilators for CF. For this review 'inhaled' includes the use of pressurised metered dose inhalers (MDIs), with or without a spacer, dry powder devices and nebulisers.

OBJECTIVES

To evaluate short-acting inhaled bronchodilators in children and adults with CF in terms of clinical outcomes and safety.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books on 28 March 2022 and searched trial registries for any new or ongoing trials on 12 April 2022. We also searched the reference lists of relevant articles and reviews.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) or quasi-RCTs that looked at the effect of any short-acting inhaled bronchodilator delivered by any device, at any dose, at any frequency and for any duration compared to either placebo or another short-acting inhaled bronchodilator in people with CF. We screened references as per standard Cochrane methodology.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed risk of bias using the Cochrane RoB 1 tool. Where we were not able to enter data into our analyses we reported results directly from the papers. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

We included 11 trials from our systematic search, with 191 participants meeting our inclusion criteria; three of these trials had three treatment arms. Eight trials compared short-acting inhaled beta-2 agonists to placebo and four trials compared short-acting inhaled muscarinic antagonists to placebo. Three trials compared short-acting inhaled beta-2 agonists to short-acting inhaled muscarinic antagonists. All were cross-over trials with only small numbers of participants. We were only able to enter data into the analysis from three trials comparing short-acting inhaled beta-2 agonists to placebo. Short-acting inhaled beta-2 agonists versus placebo All eight trials (six single-dose trials and two longer-term trials) reporting on this comparison reported on forced expiratory volume in 1 second (FEV1), either as per cent predicted (% predicted) or L. We were able to combine the data from two trials in a meta-analysis which showed a greater per cent change from baseline in FEV1 L after beta-2 agonists compared to placebo (mean difference (MD) 6.95%, 95% confidence interval (CI) 1.88 to 12.02; 2 trials, 82 participants). Only one of the longer-term trials reported on exacerbations, as measured by hospitalisations and courses of antibiotics. Only the second longer-term trial presented results for participant-reported outcomes. Three trials narratively reported adverse events, and these were all mild. Three single-dose trials and the two longer trials reported on forced vital capacity (FVC), and five trials reported on peak expiratory flow, i.e. forced expiratory flow between 25% and 75% (FEF25-75). One trial reported on airway clearance in terms of sputum weight. We judged the certainty of evidence for each of these outcomes to be very low, meaning we are very uncertain about the effect of short-acting inhaled beta-2 agonists on any of the outcomes we assessed. Short-acting inhaled muscarinic antagonists versus placebo All four trials reporting on this comparison looked at the effects of ipratropium bromide, but in different doses and via different delivery methods. One trial reported FEV1 % predicted; three trials measured this in L. Two trials reported adverse events, but these were few and mild. One trial reported FVC and three trials reported FEF25-75. None of the trials reported on quality of life, exacerbations or airway clearance. We judged the certainty of evidence for each of these outcomes to be very low, meaning we are very uncertain about the effect of short-acting inhaled muscarinic antagonists on any of the outcomes we assessed. Short-acting inhaled beta-2 agonists versus short-acting inhaled muscarinic antagonists  None of the three single-dose trials reporting on this comparison provided data we could analyse. The original papers from three trials report that both treatments lead to an improvement in FEV1 L. Only one trial reported on adverse events; but none were experienced by any participant. No trial reported on any of our other outcomes. We judged the certainty of evidence to be very low, meaning we are very uncertain about the effect of short-acting inhaled beta-2 agonists compared to short-acting inhaled muscarinic antagonists on any of the outcomes we assessed.

AUTHORS' CONCLUSIONS

All included trials in this review are small and of a cross-over design. Most trials looked at very short-term effects of inhaled bronchodilators, and therefore did not measure longer-term outcomes. The certainty of evidence across all outcomes was very low, and therefore we have been unable to describe any effects with certainty.

Treatment of Pulmonary Disease of Cystic Fibrosis: A Comprehensive Review

Cystic fibrosis (CF) is a genetic disease that causes absence or dysfunction of a protein named transmembrane conductance regulatory protein (CFTR) that works as an anion channel. As a result, the secretions of the organs where CFTR is expressed are very viscous, so their functionality is altered. The main cause of morbidity is due to the involvement of the respiratory system as a result of recurrent respiratory infections by different pathogens. In recent decades, survival has been increasing, rising by around age 50. This is due to the monitoring of patients in multidisciplinary units, early diagnosis with neonatal screening, and advances in treatments. In this chapter, we will approach the different therapies used in CF for the treatment of symptoms, obstruction, inflammation, and infection. Moreover, we will discuss specific and personalized treatments to correct the defective gene and repair the altered protein CFTR. The obstacle for personalized CF treatment is to predict the drug response of patients due to genetic complexity and heterogeneity of uncommon mutations.

Nanomedicine Approaches for the Pulmonary Treatment of Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disease affecting today nearly 70,000 patients worldwide and characterized by a hypersecretion of thick mucus difficult to clear arising from the defective CFTR protein. The over-production of the mucus secreted in the lungs, along with its altered composition and consistency, results in airway obstruction that makes the lungs susceptible to recurrent and persistent bacterial infections and endobronchial chronic inflammation, which are considered the primary cause of bronchiectasis, respiratory failure, and consequent death of patients. Despite the difficulty of treating the continuous infections caused by pathogens in CF patients, various strategies focused on the symptomatic therapy have been developed during the last few decades, showing significant positive impact on prognosis. Moreover, nowadays, the discovery of CFTR modulators as well as the development of gene therapy have provided new opportunity to treat CF. However, the lack of effective methods for delivery and especially targeted delivery of therapeutics specifically to lung tissues and cells limits the efficiency of the treatments. Nanomedicine represents an extraordinary opportunity for the improvement of current therapies and for the development of innovative treatment options for CF previously considered hard or impossible to treat. Due to the peculiar environment in which the therapies have to operate characterized by several biological barriers (pulmonary tract, mucus, epithelia, bacterial biofilm) the use of nanotechnologies to improve and enhance drug delivery or gene therapies is an extremely promising way to be pursued. The aim of this review is to revise the currently used treatments and to outline the most recent progresses about the use of nanotechnology for the management of CF.

Brazilian guidelines for the diagnosis and treatment of cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive genetic disorder characterized by dysfunction of the CFTR gene. It is a multisystem disease that most often affects White individuals. In recent decades, various advances in the diagnosis and treatment of CF have drastically changed the scenario, resulting in a significant increase in survival and quality of life. In Brazil, the current neonatal screening program for CF has broad coverage, and most of the Brazilian states have referral centers for the follow-up of individuals with the disease. Previously, CF was limited to the pediatric age group. However, an increase in the number of adult CF patients has been observed, because of the greater number of individuals being diagnosed with atypical forms (with milder phenotypic expression) and because of the increase in life expectancy provided by the new treatments. However, there is still great heterogeneity among the different regions of Brazil in terms of the access of CF patients to diagnostic and therapeutic methods. The objective of these guidelines was to aggregate the main scientific evidence to guide the management of these patients. A group of 18 CF specialists devised 82 relevant clinical questions, divided into five categories: characteristics of a referral center; diagnosis; treatment of respiratory disease; gastrointestinal and nutritional treatment; and other aspects. Various professionals working in the area of CF in Brazil were invited to answer the questions devised by the coordinators. We used the PubMed database to search the available literature based on keywords, in order to find the best answers to these questions.