The effect of high doses of inhaled salbutamol and ipratropium bromide in patients with stable 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 A Cochrane Review looking at both short- and long-acting inhaled bronchodilators for CF was withdrawn from the Cochrane Library in 2016. That review has been replaced by two separate Cochrane Reviews: one on long-acting inhaled bronchodilators for CF, and this review on short-acting inhaled bronchodilators for CF.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.

WITHDRAWN: Inhaled bronchodilators for cystic fibrosis

This review has been withdrawn because it has been split into the following reviews: 'Long‐acting inhaled bronchodilators for cystic fibrosis' and 'Short‐acting inhaled bronchodilators for cystic fibrosis'.

The editorial group responsible for this previously published document have withdrawn it from publication.

Cystic fibrosis pulmonary guidelines: chronic medications for maintenance of lung health

RATIONALE

Cystic fibrosis is a recessive genetic disease characterized by dehydration of the airway surface liquid and impaired mucociliary clearance. As a result, individuals with the disease have difficulty clearing pathogens from the lung and experience chronic pulmonary infections and inflammation. Death is usually a result of respiratory failure. Newly introduced therapies and aggressive management of the lung disease have resulted in great improvements in length and quality of life, with the result that the median expected survival age has reached 36 years. However, as the number of treatments expands, the medical regimen becomes increasingly burdensome in time, money, and health resources. Hence, it is important that treatments should be recommended on the basis of available evidence of efficacy and safety.

OBJECTIVES

The Cystic Fibrosis Foundation therefore established a committee to examine the clinical evidence for each therapy and to provide guidance for the prescription of these therapies.

METHODS

The committee members developed and refined a series of questions related to drug therapies used in the maintenance of pulmonary function. We addressed the questions in one of three ways, based on available evidence: (1) commissioned systematic review, (2) modified systematic review, or (3) summary of existing Cochrane reviews.

CONCLUSIONS

It is hoped that the guidelines provided in this article will facilitate the appropriate application of these treatments to improve and extend the lives of all individuals with cystic fibrosis.

Inhaled bronchodilators for cystic fibrosis

BACKGROUND

Recurrent wheeze and breathlessness are common in people with cystic fibrosis, and bronchodilators are commonly prescribed. Despite their wide-scale and often long-term use, there is limited objective evidence about their efficacy in cystic fibrosis.

OBJECTIVES

To evaluate the effectiveness of inhaled bronchodilators in children and adults with cystic fibrosis.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic databases searches, and handsearches of relevant journals and abstract books of conference proceedings. Latest search of the Group's Trials Register: August 2005

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing inhaled bronchodilators to placebo or another inhaled bronchodilator in people with CF, diagnosed clinically and by sweat or genetic testing and at all stages and severity of lung disease.

DATA COLLECTION AND ANALYSIS

The authors independently extracted data and assessed trial quality. If data were missing, the primary author was contacted where possible. The data were subgrouped into classes of bronchodilator and for each class into short-term effects (less than one week) and long-term effects (greater or equal to one week).

MAIN RESULTS

The search identified 43 references. Fourteen trials, with a total of 257 participants, were suitable for inclusion. The trials were all cross-over in design; in this case a meta-analysis was not possible. There were varied conclusions from the different trials, reflecting their heterogeneity. Compared to placebo, short-acting beta-2 agonists increased forced expiratory volume at one second (FEV(1)) in the short term in three out of five trials, and in the long-term increased peak expiratory flow rate in individuals who had been shown to have bronchial hyperreactivity or bronchodilator responsiveness or both. Compared to placebo, long-acting beta-2 agonists increased FEV(1) and forced expiratory flow between 25% and 75% of expiratory flow (FEF 25-75%) in the short term in participants known to have bronchodilator responsiveness, but produced inconsistent results in long-term trials. Short acting-anticholinergics had no consistent effect on lung function tests in either the short or the long term. We found no published trials of fenoterol, formoterol or tiotropium and the use of these agents in cystic fibrosis cannot be supported.

AUTHORS' CONCLUSIONS

It was not possible to determine fully the effectiveness of inhaled bronchodilators in cystic fibrosis as a meta-analysis was not possible. However, both short and long-acting beta-2 agonists can be beneficial both in the short and long term in individuals with demonstrable bronchodilator responsiveness or bronchial hyperrresponsiveness.

Long-acting bronchodilators in cystic fibrosis

PURPOSE OF REVIEW

Over 80% of patients with cystic fibrosis (CF) have bronchodilator therapy prescribed, yet bronchodilator use in CF remains controversial. The development of long-acting beta-agonist drugs for clinical use has provided additional rationale for considering bronchodilator therapy in CF. This paper will review recent developments in bronchodilator use in CF patients, with emphasis on the long-acting beta agonists.

RECENT FINDINGS

It is reported that 50 to 60% of CF patients demonstrate significant intermittent airway hyperreactivity in response to bronchodilators or challenges. The beta-agonist drugs are the most commonly prescribed bronchodilators. Several mechanisms may be implicated in therapeutic response of CF patients to bronchodilators including direct smooth muscle relaxation, increased mucociliary clearance, direct effects on inflammatory cells and bacterial adherence, and possible direct effects on CF transmembrane conductance regulator (CFTR) function. Several recent studies have shown improved outcomes with long-acting bronchodilators.

SUMMARY

In spite of the widespread use of bronchodilators, there are very few long-term studies of their effects in CF patients. However, there are clearly clinical benefits in certain situations. Further research into the most appropriate utilization of these medications to improve outcomes in patients with CF would be helpful.

Pathophysiology and management of pulmonary infections in cystic fibrosis

This comprehensive State of the Art review summarizes the current published knowledge base regarding the pathophysiology and microbiology of pulmonary disease in cystic fibrosis (CF). The molecular basis of CF lung disease including the impact of defective cystic fibrosis transmembrane regulator (CFTR) protein function on airway physiology, mucociliary clearance, and establishment of Pseudomonas aeruginosa infection is described. An extensive review of the microbiology of CF lung disease with particular reference to infection with P. aeruginosa is provided. Other pathogens commonly associated with CF lung disease including Staphylococcal aureus, Burkholderia cepacia, Stenotrophomonas maltophilia, Achromobacter xylosoxidans and atypical mycobacteria are also described. Clinical presentation and assessment of CF lung disease including diagnostic microbiology and other measures of pulmonary health are reviewed. Current recommendations for management of CF lung disease are provided. An extensive review of antipseudomonal therapies in the settings of treatment for early P. aeruginosa infection, maintenance for patients with chronic P. aeruginosa infection, and treatment of exacerbation in pulmonary symptoms, as well as antibiotic therapies for other CF respiratory pathogens, are included. In addition, the article discusses infection control policies, therapies to optimize airway clearance and reduce inflammation, and potential future therapies.

Effectiveness and tolerability of high-dose salmeterol in cystic fibrosis

The efficacy and tolerability of high-dose salmeterol (100 mcg, BID) and albuterol (2.5 mg, BID) were compared with those of albuterol (2.5 mg, BID) in outpatients with cystic fibrosis in a randomized, double-blind, double-dummy, placebo-controlled, crossover study with both short- (4 weeks of each) and long-term (24 weeks of each) treatment periods. The primary outcome measure was the difference in mean change in forced expired volume in 1 sec (FEV(1)) from baseline to the end of each treatment, and secondary measures included changes in forced vital capacity (FVC), forced expiratory flow between 25-75% of FVC (FEF(25-75)), patient-rated weekly symptom scores, number of extra (rescue) albuterol treatments, and number of antibiotic treatments. Tolerability was evaluated by changes in vital signs and adverse events.Thirty-six out of 44 patients enrolled finished the short-term treatment period, and 19 out of 23 who continued the study also finished the long-term treatment period. There was no significant difference in the mean % change in FEV(1) from baseline to completion of 4 weeks with each drug in the short-term treatment period (0.1% vs. 0.06%, albuterol vs. salmeterol; respectively). In the long-term treatment period, there was a significant decrease from baseline in FEV(1) with albuterol vs. salmeterol, as measured after both 12 and 24 weeks of each treatment (-6.2% vs. 1.8%, P = 0.013 after 12 weeks, and -6.5% vs. 1.7%, P = 0.002, after 24 weeks, respectively). In both treatment periods, salmeterol was well-tolerated. While there were more rescue treatments per patient per week with albuterol than with salmeterol treatment in both the short- and long-term periods (0.67 vs. 0.40 and 1.76 vs. 0.74, respectively), rescue treatments were needed significantly more often for only the long-term period with albuterol compared to salmeterol (P = 0.022). Also, there were more antibiotic interventions with albuterol than with salmeterol treatment in both the short- and long-term periods (25 vs. 10 and 56 vs. 42, respectively); however, antibiotics were needed significantly more often for only the short-term period (P = 0.011). In addition, there was a significantly higher symptom score with albuterol vs. salmeterol treatment during the second half of the long-term period (1.24 vs. 0.89, P = 0.001).In conclusion, long-term high-dose salmeterol was equally safe and was associated with better pulmonary function, fewer interventions, and fewer respiratory symptoms compared to standard therapy with albuterol in a population of outpatients with mild to moderate CF.

Airways reactivity in patients with CF

Airways reactivity, hyper-reactivity, and hyper-responsiveness are terms used to describe airways for which there appears to be increased bronchial smooth muscle tone or responsiveness. Some patients with cystic fibrosis (CF) have concomitant asthma causing airway hyperresponsiveness as manifested by recurrent acute symptoms of dyspnea that is impressively responsive to an inhaled beta 2 agonist and/or systemic corticosteroids. However, many others have a degree of bronchodilator responsiveness in the absence of an impressive clinical response to such anti-asthmatic treatment. In contrast to those with asthma, exercise does not induce bronchospasm and can even cause bronchodilatation in patients with CF who have bronchodilator responsiveness in the absence of asthma. The airway hyperresponsiveness of CF also differs in its response to histamine induced bronchospasm which is effectively reversed with ipratropium in patients with CF who symptomatically do not have asthma, whereas ipratropium does not adequately reverse histamine-induced bronchospasm in those with concomitant symptoms of asthma. These and other data suggest that the increased airway reactivity in patients with CF is vagally mediated and results from the airway damage caused by the lung disease. The use of bronchodilators as a routine part of CF lung disease care is controversial, but there is little evidence that treating airway reactivity in patients with CF is of clinical importance as a routine measure in the absence of clinical asthma. Definite subjective improvement in symptoms or improved sputum production when a bronchodilator precedes chest physical therapy should be sought to justify continued use in individual patients.

Effects of standard and high doses of salmeterol on lung function of hospitalized patients with cystic fibrosis

In a recent investigation we found that hospitalized patients with cystic fibrosis who received 0.5 cc of 0.5% albuterol nebulizer solution TID significantly increased their pulmonary function across the day, but fell back to baseline overnight. To determine whether this fall could be prevented by the long-acting beta-2 agonist salmeterol at both standard (2 puffs: 42 mcg BID) and high (4 puffs, 84 mcg BID) doses, we evaluated the effects of salmeterol vs. albuterol (2 puffs, 180 mcg QID, and 4 puffs, 360 mcg BID) in a placebo-controlled three-way random crossover, double-blind trial. Eighteen patients in the low-dose group and 10 of the same 18 patients in the high-dose group completed the 3 consecutive days of testing and received either salmeterol, albuterol, or placebo with each of four chest physiotherapy sessions given at 7 AM, 11 AM, 3 PM, and 7 PM. At standard doses (2 puffs), the mean percent changes in FEV1 pre- to post-7 AM therapy for salmeterol (5.5%) and albuterol (9.9%) were significantly greater than with placebo (-1.2%) (P < 0.05 and 0.01, respectively). The mean percent changes in FEV1 from morning baseline with salmeterol were also significantly greater than placebo before 3 PM (12.1% vs. 5.4%, P < 0.01), and neither albuterol nor salmeterol were significantly greater than placebo after 3 PM. At standard doses there was a significant carryover effect with salmeterol to the next morning for the FEV1 (7.3%) when compared to placebo (1.5%) and albuterol (-0.7%) (P < 0.05 and 0.05, respectively). At high doses (4 puffs), the mean percent change in FEV1 with pre- to post-7 AM therapy increased to 22.7% and remained significantly greater than with placebo until pretherapy at 7 PM. The carryover effect the next morning was 14.7%. Salmeterol at 4 puffs compared favorably to albuterol nebulizer therapy given TID in both the incidence of responders for the FEV1 (70% vs. 71%) and the mean changes after therapy at 7 AM (22.7% vs. 14.9%), and provided greater carryover effects to the next morning (14.7% vs. -0.7%), thus preventing the fall in pulmonary function back to baseline overnight. We recommend the use of high-dose salmeterol in hospitalized patients with FVC values of 40% of predicted or greater, starting with 2 and increasing to 4 puffs BID as tolerated.

Routine nebulized ipratropium and albuterol together are better than either alone in COPD. The COMBIVENT Inhalation Solution Study Group

STUDY OBJECTIVE

We compared the long-term safety and efficacy of the combination ipratropium bromide (IB) and albuterol sulfate (ALB) inhalation solution with that of each separate component using three-times-daily administration.

DESIGN

Using a parallel design, we randomized patients to receive 3.0 mg ALB, 0.5 mg IB, or the combination by small-volume nebulizer (SVN) for 85 days. Subjects were allowed to use up to two extra doses of study medication daily for control of symptoms on an as-needed basis. The main efficacy evaluation was the acute pulmonary function response to an aerosol of the maintenance study medication over the course of the investigation. Physician global evaluation, subject quality of life assessments, COPD symptom scores, and twice-daily peak expiratory flow rate (PEFR) were also assessed over the study period.

SETTING

Twenty-five centers participated in the investigation.

PATIENTS

We studied 652 patients with moderate to severe COPD.

MEASUREMENTS AND RESULTS

Over the course of the study, the acute spirometric response and evening PEFR values with the SVN combination of IB plus ALB were statistically significantly better compared to ALB or IB alone. The quality of life scores, physician global evaluations, symptom scores, and morning PEFR scores were unchanged over the duration of the study in all treatment groups. There was no significant difference in adverse events in the three treatment groups.

CONCLUSIONS

In patients with COPD, maintenance SVN therapy with IB and ALB provides better bronchodilation than either therapy alone without increasing side effects.