BACKGROUND: There has been renewal of interest in the use of prophylactic antibiotics to reduce the frequency of exacerbations and improve quality of life in chronic obstructive pulmonary disease (COPD).
OBJECTIVES: To determine whether or not regular (continuous, intermittent or pulsed) treatment of COPD patients with prophylactic antibiotics reduces exacerbations or affects quality of life.
SEARCH METHODS: We searched the Cochrane Airways Group Trials Register and bibliographies of relevant studies. The latest literature search was performed on 27 July 2018.
SELECTION CRITERIA: Randomised controlled trials (RCTs) that compared prophylactic antibiotics with placebo in patients with COPD.
DATA COLLECTION AND ANALYSIS: We used the standard Cochrane methods. Two independent review authors selected studies for inclusion, extracted data, and assessed risk of bias. We resolved discrepancies by involving a third review author.
MAIN RESULTS: We included 14 studies involving 3932 participants in this review. We identified two further studies meeting inclusion criteria but both were terminated early without providing results. All studies were published between 2001 and 2015. Nine studies were of continuous macrolide antibiotics, two studies were of intermittent antibiotic prophylaxis (three times per week) and two were of pulsed antibiotic regimens (e.g. five days every eight weeks). The final study included one continuous, one intermittent and one pulsed arm. The antibiotics investigated were azithromycin, erythromycin, clarithromycin, doxycyline, roxithromycin and moxifloxacin. The study duration varied from three months to 36 months and all used intention-to-treat analysis. Most of the pooled results were of moderate quality. The risk of bias of the included studies was generally low.The studies recruited participants with a mean age between 65 and 72 years and mostly at least moderate-severity COPD. Five studies only included participants with frequent exacerbations and two studies recruited participants requiring systemic steroids or antibiotics or both, or who were at the end stage of their disease and required oxygen. One study recruited participants with pulmonary hypertension secondary to COPD and a further study was specifically designed to asses whether eradication of Chlamydia pneumoniae reduced exacerbation rates.The co-primary outcomes for this review were the number of exacerbations and quality of life.With use of prophylactic antibiotics, the number of participants experiencing one or more exacerbations was reduced (odds ratio (OR) 0.57, 95% CI 0.42 to 0.78; participants = 2716; studies = 8; moderate-quality evidence). This represented a reduction from 61% of participants in the control group compared to 47% in the treatment group (95% CI 39% to 55%). The number needed to treat for an additional beneficial outcome with prophylactic antibiotics given for three to 12 months to prevent one person from experiencing an exacerbation (NNTB) was 8 (95% CI 5 to 17). The test for subgroup difference suggested that continuous and intermittent antibiotics may be more effective than pulsed antibiotics (P = 0.02, I² = 73.3%).The frequency of exacerbations per patient per year was also reduced with prophylactic antibiotic treatment (rate ratio 0.67; 95% CI 0.54 to 0.83; participants = 1384; studies = 5; moderate-quality evidence). Although we were unable to pool the result, six of the seven studies reporting time to first exacerbation identified an increase (i.e. benefit) with antibiotics, which was reported as statistically significant in four studies.There was a statistically significant improvement in quality of life as measured by the St George's Respiratory Questionnaire (SGRQ) with prophylactic antibiotic treatment, but this was smaller than the four unit improvement that is regarded as being clinically significant (mean difference (MD) -1.94, 95% CI -3.13 to -0.75; participants = 2237; studies = 7, high-quality evidence).Prophylactic antibiotics showed no significant effect on the secondary outcomes of frequency of hospital admissions, change in forced expiratory volume in one second (FEV1), serious adverse events or all-cause mortality (moderate-quality evidence). There was some evidence of benefit in exercise tolerance, but this was driven by a single study of lower methodological quality.The adverse events that were recorded varied among the studies depending on the antibiotics used. Azithromycin was associated with significant hearing loss in the treatment group, which was in many cases reversible or partially reversible. The moxifloxacin pulsed study reported a significantly higher number of adverse events in the treatment arm due to the marked increase in gastrointestinal adverse events (P < 0.001). Some adverse events that led to drug discontinuation, such as development of long QTc or tinnitus, were not significantly more frequent in the treatment group than the placebo group but pose important considerations in clinical practice.The development of antibiotic resistance in the community is of major concern. Six studies reported on this, but we were unable to combine results. One study found newly colonised participants to have higher rates of antibiotic resistance. Participants colonised with moxifloxacin-sensitive pseudomonas at initiation of therapy rapidly became resistant with the quinolone treatment. A further study with three active treatment arms found an increase in the degree of antibiotic resistance of isolates in all three arms after 13 weeks treatment.
AUTHORS' CONCLUSIONS: Use of continuous and intermittent prophylactic antibiotics results in a clinically significant benefit in reducing exacerbations in COPD patients. All studies of continuous and intermittent antibiotics used macrolides, hence the noted benefit applies only to the use of macrolide antibiotics prescribed at least three times per week. The impact of pulsed antibiotics remains uncertain and requires further research.The studies in this review included mostly participants who were frequent exacerbators with at least moderate-severity COPD. There were also older individuals with a mean age over 65 years. The results of these studies apply only to the group of participants who were studied in these studies and may not be generalisable to other groups.Because of concerns about antibiotic resistance and specific adverse effects, consideration of prophylactic antibiotic use should be mindful of the balance between benefits to individual patients and the potential harms to society created by antibiotic overuse. Monitoring of significant side effects including hearing loss, tinnitus, and long QTc in the community in this elderly patient group may require extra health resources.
Long-term treatment with macrolides has recently been shown to reduce COPD exacerbations in doses lower than bactericidal doses. This article aims to critically review the international literature relating to the long-term effectiveness and safety of macrolides and to estimate the budget impact of preventing exacerbations with azithromycin in Belgium. Controlled clinical studies focusing on the prevention of COPD exacerbations with long-term macrolide treatment were identified in PubMed, EMBASE, Controlled Trials Registry of the Cochrane Library, and Social Science and Citation Index. The budget impact of preventing exacerbations with azithromycin in Belgium over a one-year period was calculated as the difference between the additional expenditure of annual treatment with azithromycin and the savings in hospital expenditure arising from fewer COPD exacerbations in patients with GOLD stages II-IV. Prevalence and resource use data were derived from the literature and unit cost data from Belgian sources. The literature review suggests that long-term treatment of COPD patients with azithromycin, erythromycin or clarithromycin is effective and safe, and reduces exacerbations and related hospitalizations. However, uncertainty remains about the specific patient population that is most likely to benefit from long-term macrolide treatment, the optimal dose and duration of macrolide treatment, and the potential impact of long-term macrolide treatment on resistance. The budget impact analysis demonstrated that annual hospital savings of €950 million resulting from fewer exacerbations outweighed additional expenditure on azithromycin of €595 million, implying that the prevention of COPD exacerbations with azithromycin is a cost saving strategy in Belgium.
BACKGROUND: Macrolide antibiotics have anti-inflammatory effects, and long-term administration may reduce chronic obstructive pulmonary disease (COPD) exacerbations. OBJECTIVE: To investigate the effects of long-term treatment of macrolide therapy for COPD. METHODS: We searched the PubMed and Embase databases to identify randomized controlled trials that evaluated the effect of macrolide therapy (of at least 2 weeks) for COPD. The primary outcome assessed was the frequency of acute exacerbations during follow-up. RESULTS: Six trials involving 1,485 COPD patients were included in the analysis. Analysis of the pooled data of all 6 trials showed that macrolide administration reduced the frequency of acute exacerbations of COPD [risk ratio (RR) = 0.62; 95% CI 0.43-0.89, p = 0.01]. Subgroup analysis showed that only erythromycin might be associated with decreased COPD exacerbations (erythromycin: p = 0.04, azithromycin: p = 0.22, clarithromycin: p = 0.18). Moreover, macrolide therapy for 3 months did not significantly reduce the number of exacerbations (p = 0.18), whereas a beneficial effect was conclusive in the 6-month (p = 0.009) and 12-month (p = 0.03) treatment subgroups. In addition, nonfatal adverse events were more frequent in the macrolide treatment groups than in the controls (RR = 1.32; 95% CI 1.06-1.64, p = 0.01). However, related clinical factors had no influence on the overall result (p = 0.19). There was no publication bias among the included trials. CONCLUSIONS: Macrolide therapy was effective and safe in decreasing the frequency of exacerbations in patients with COPD. Treatment might provide a significant benefit but only when therapy lasts more than 6 months.
INTRODUCTION: Macrolides are of unique interest in preventing COPD exacerbations because they possess a variety of antibacterial, antiviral and anti-inflammatory properties. Recent research has generated renewed interest in prophylactic macrolides to reduce the risk of COPD exacerbations. Little is known about how well these recent findings fit within the context of previous research on this subject. The purpose of this article is to evaluate, via exploratory meta-analysis, whether the overall consensus favors prophylactic macrolides for prevention of COPD exacerbations.
METHODS: EMBASE, Cochrane and Medline databases were searched for all relevant randomized controlled trials (RCTs). Six RCTs were identified. The primary endpoint was incidence of COPD exacerbations. Secondary endpoints including mortality, hospitalization rates, adverse events and likelihood of having at least one COPD exacerbation were also examined.
RESULTS: There was a 37% relative risk reduction (RR = 0.63, 95% CI: 0.45-0.87, p value = 0.005) in COPD exacerbations among patients taking macrolides compared to placebo. Furthermore, there was a 21% reduced risk of hospitalization (RR = 0.79, 95% CI: 0.69-0.90, p-value = 0.01) and 68% reduced risk of having at least one COPD exacerbation (RR = 0.34, 95% CI 0.21-0.54, p-value = 0.001) among patients taking macrolides versus placebo. There was also a trend toward decreased mortality and increased adverse events among patients taking macrolides but these were not statistically significant.
CONCLUSIONS: Prophylactic macrolides are an effective approach for reducing incident COPD exacerbations. There were several limitations to this study including a lack of consistent adverse event reporting and some degree of clinical and statistical heterogeneity between studies.
There has been renewal of interest in the use of prophylactic antibiotics to reduce the frequency of exacerbations and improve quality of life in chronic obstructive pulmonary disease (COPD).
OBJECTIVES:
To determine whether or not regular (continuous, intermittent or pulsed) treatment of COPD patients with prophylactic antibiotics reduces exacerbations or affects quality of life.
SEARCH METHODS:
We searched the Cochrane Airways Group Trials Register and bibliographies of relevant studies. The latest literature search was performed on 27 July 2018.
SELECTION CRITERIA:
Randomised controlled trials (RCTs) that compared prophylactic antibiotics with placebo in patients with COPD.
DATA COLLECTION AND ANALYSIS:
We used the standard Cochrane methods. Two independent review authors selected studies for inclusion, extracted data, and assessed risk of bias. We resolved discrepancies by involving a third review author.
MAIN RESULTS:
We included 14 studies involving 3932 participants in this review. We identified two further studies meeting inclusion criteria but both were terminated early without providing results. All studies were published between 2001 and 2015. Nine studies were of continuous macrolide antibiotics, two studies were of intermittent antibiotic prophylaxis (three times per week) and two were of pulsed antibiotic regimens (e.g. five days every eight weeks). The final study included one continuous, one intermittent and one pulsed arm. The antibiotics investigated were azithromycin, erythromycin, clarithromycin, doxycyline, roxithromycin and moxifloxacin. The study duration varied from three months to 36 months and all used intention-to-treat analysis. Most of the pooled results were of moderate quality. The risk of bias of the included studies was generally low.The studies recruited participants with a mean age between 65 and 72 years and mostly at least moderate-severity COPD. Five studies only included participants with frequent exacerbations and two studies recruited participants requiring systemic steroids or antibiotics or both, or who were at the end stage of their disease and required oxygen. One study recruited participants with pulmonary hypertension secondary to COPD and a further study was specifically designed to asses whether eradication of Chlamydia pneumoniae reduced exacerbation rates.The co-primary outcomes for this review were the number of exacerbations and quality of life.With use of prophylactic antibiotics, the number of participants experiencing one or more exacerbations was reduced (odds ratio (OR) 0.57, 95% CI 0.42 to 0.78; participants = 2716; studies = 8; moderate-quality evidence). This represented a reduction from 61% of participants in the control group compared to 47% in the treatment group (95% CI 39% to 55%). The number needed to treat for an additional beneficial outcome with prophylactic antibiotics given for three to 12 months to prevent one person from experiencing an exacerbation (NNTB) was 8 (95% CI 5 to 17). The test for subgroup difference suggested that continuous and intermittent antibiotics may be more effective than pulsed antibiotics (P = 0.02, I² = 73.3%).The frequency of exacerbations per patient per year was also reduced with prophylactic antibiotic treatment (rate ratio 0.67; 95% CI 0.54 to 0.83; participants = 1384; studies = 5; moderate-quality evidence). Although we were unable to pool the result, six of the seven studies reporting time to first exacerbation identified an increase (i.e. benefit) with antibiotics, which was reported as statistically significant in four studies.There was a statistically significant improvement in quality of life as measured by the St George's Respiratory Questionnaire (SGRQ) with prophylactic antibiotic treatment, but this was smaller than the four unit improvement that is regarded as being clinically significant (mean difference (MD) -1.94, 95% CI -3.13 to -0.75; participants = 2237; studies = 7, high-quality evidence).Prophylactic antibiotics showed no significant effect on the secondary outcomes of frequency of hospital admissions, change in forced expiratory volume in one second (FEV1), serious adverse events or all-cause mortality (moderate-quality evidence). There was some evidence of benefit in exercise tolerance, but this was driven by a single study of lower methodological quality.The adverse events that were recorded varied among the studies depending on the antibiotics used. Azithromycin was associated with significant hearing loss in the treatment group, which was in many cases reversible or partially reversible. The moxifloxacin pulsed study reported a significantly higher number of adverse events in the treatment arm due to the marked increase in gastrointestinal adverse events (P < 0.001). Some adverse events that led to drug discontinuation, such as development of long QTc or tinnitus, were not significantly more frequent in the treatment group than the placebo group but pose important considerations in clinical practice.The development of antibiotic resistance in the community is of major concern. Six studies reported on this, but we were unable to combine results. One study found newly colonised participants to have higher rates of antibiotic resistance. Participants colonised with moxifloxacin-sensitive pseudomonas at initiation of therapy rapidly became resistant with the quinolone treatment. A further study with three active treatment arms found an increase in the degree of antibiotic resistance of isolates in all three arms after 13 weeks treatment.
AUTHORS' CONCLUSIONS:
Use of continuous and intermittent prophylactic antibiotics results in a clinically significant benefit in reducing exacerbations in COPD patients. All studies of continuous and intermittent antibiotics used macrolides, hence the noted benefit applies only to the use of macrolide antibiotics prescribed at least three times per week. The impact of pulsed antibiotics remains uncertain and requires further research.The studies in this review included mostly participants who were frequent exacerbators with at least moderate-severity COPD. There were also older individuals with a mean age over 65 years. The results of these studies apply only to the group of participants who were studied in these studies and may not be generalisable to other groups.Because of concerns about antibiotic resistance and specific adverse effects, consideration of prophylactic antibiotic use should be mindful of the balance between benefits to individual patients and the potential harms to society created by antibiotic overuse. Monitoring of significant side effects including hearing loss, tinnitus, and long QTc in the community in this elderly patient group may require extra health resources.
