Antibiotics for community acquired pneumonia in adult outpatients

Antibiotics for community-acquired pneumonia in adult outpatients

BACKGROUND

Lower respiratory tract infection (LRTI) is the third leading cause of death worldwide and the first leading cause of death in low-income countries. Community-acquired pneumonia (CAP) is a common condition that causes a significant disease burden for the community, particularly in children younger than five years, the elderly and immunocompromised people. Antibiotics are the standard treatment for CAP. However, increasing antibiotic use is associated with the development of bacterial resistance and side effects for the patient. Several studies have been published regarding optimal antibiotic treatment for CAP but many of these data address treatments in hospitalised patients. This is an update of our 2009 Cochrane Review and addresses antibiotic therapies for CAP in outpatient settings.

OBJECTIVES

To compare the efficacy and safety of different antibiotic treatments for CAP in participants older than 12 years treated in outpatient settings with respect to clinical, radiological and bacteriological outcomes.

SEARCH METHODS

We searched CENTRAL (2014, Issue 1), MEDLINE (January 1966 to March week 3, 2014), EMBASE (January 1974 to March 2014), CINAHL (2009 to March 2014), Web of Science (2009 to March 2014) and LILACS (2009 to March 2014).

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs), fully published in peer-reviewed journals, of antibiotics versus placebo as well as antibiotics versus another antibiotic for the treatment of CAP in outpatient settings in participants older than 12 years of age. However, we did not find any studies of antibiotics versus placebo. Therefore, this review includes RCTs of one or more antibiotics, which report the diagnostic criteria and describe the clinical outcomes considered for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors (LMB, TJMV) independently assessed study reports in the first publication. In the 2009 update, LMB performed study selection, which was checked by TJMV and MMK. In this 2014 update, two review authors (SP, SM) independently performed and checked study selection. We contacted trial authors to resolve any ambiguities in the study reports. We compiled and analysed the data. We resolved differences between review authors by discussion and consensus.

MAIN RESULTS

We included 11 RCTs in this review update (3352 participants older than 12 years with a diagnosis of CAP); 10 RCTs assessed nine antibiotic pairs (3321 participants) and one RCT assessed four antibiotics (31 participants) in people with CAP. The study quality was generally good, with some differences in the extent of the reporting. A variety of clinical, bacteriological and adverse events were reported. Overall, there was no significant difference in the efficacy of the various antibiotics. Studies evaluating clarithromycin and amoxicillin provided only descriptive data regarding the primary outcome. Though the majority of adverse events were similar between all antibiotics, nemonoxacin demonstrated higher gastrointestinal and nervous system adverse events when compared to levofloxacin, while cethromycin demonstrated significantly more nervous system side effects, especially dysgeusia, when compared to clarithromycin. Similarly, high-dose amoxicillin (1 g three times a day) was associated with higher incidence of gastritis and diarrhoea compared to clarithromycin, azithromycin and levofloxacin.

AUTHORS' CONCLUSIONS

Available evidence from recent RCTs is insufficient to make new evidence-based recommendations for the choice of antibiotic to be used for the treatment of CAP in outpatient settings. Pooling of study data was limited by the very low number of studies assessing the same antibiotic pairs. Individual study results do not reveal significant differences in efficacy between various antibiotics and antibiotic groups. However, two studies did find significantly more adverse events with use of cethromycin as compared to clarithromycin and nemonoxacin when compared to levofloxacin. Multi-drug comparisons using similar administration schedules are needed to provide the evidence necessary for practice recommendations. Further studies focusing on diagnosis, management, cost-effectiveness and misuse of antibiotics in CAP and LRTI are warranted in high-, middle- and low-income countries.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Comparative effectiveness of medical interventions in adults versus children

OBJECTIVE

To estimate the comparative effectiveness of medical interventions in adults versus children.

STUDY DESIGN

We identified from the Cochrane Database of Systematic Reviews (Issue 1, 2007) meta-analyses with data on at least 1 adult and 1 pediatric randomized trial with binary primary efficacy outcome. For each meta-analysis, we calculated the summary odds ratio of the adult trials and the pediatric trials, respectively; the relative odds ratio (ROR) of the adult versus pediatric odds ratios per meta-analysis; and the summary ROR across all meta-analyses. ROR <1 means that the experimental intervention is more unfavorable in children than adults.

RESULTS

Across 128 eligible meta-analyses (1051 adult and 343 pediatric trials), the summary ROR did not show a statistically significant difference between adults and children (0.96; 95% confidence intervals, 0.86 to 1.08). However, in all meta-analyses except for 1, the individual ROR's 95% confidence intervals could not exclude a relative difference in efficacy over 20%. In two-thirds, the relative difference in observed point estimates exceeded 50%. Nine statistically significant discrepancies were identified; 4 of them were also clinically important.

CONCLUSIONS

Treatment effects are on average similar in adults and children, but available evidence leaves large uncertainty about their relative efficacy. Clinically important discrepancies may occur.

Viral and Mycoplasma pneumoniae community-acquired pneumonia and novel clinical outcome evaluation in ambulatory adult patients in China

Few studies have addressed the etiology and clinical outcomes of community-acquired pneumonia (CAP) treated in an ambulatory setting. We investigated the etiology by the culture of Mycoplasma pneumoniae, urine antigen testing of Streptococcus pneumoniae and Legionella pneumoniae, and DNA or RNA determination of eight kinds of respiratory virus DNA or RNA. An etiological diagnosis was made in 51.8% of 197 patients. The most common pathogens were M. pneumoniae (29.4%) followed by influenza virus A, parainfluenza virus, adenovirus, human metapneumovirus (9.6%), and S. pneumoniae (4.1%). Patients with mycoplasma infections were younger, less likely to have comorbidities, and less likely to have adequate sputum for gram stain and culture. Patients with viral infections were older and more likely to have poorly defined nodules on chest X-ray (CXR) or computed tomography (CT) scan. Among patients infected with M. pneumoniae, those with quinolones as initial prescriptions had shorter duration of fever after the initiation of antibiotics than patients with β-lactams, macrolides, or β-lactams + macrolides (p < 0.05). This study suggests that M. pneumoniae and respiratory viruses were the most frequent pathogens found in ambulatory adult CAP patients and quinolones were better than β-lactams, macrolides, or β-lactams + macrolides in the resolution of fever of M. pneumoniae pneumonia.

Antibiotics for community acquired pneumonia in adult outpatients

BACKGROUND

Community-acquired pneumonia (CAP), the sixth most common cause of death worldwide, is a common condition representing a significant disease burden for the community, particularly in the elderly. Antibiotics are helpful in treating CAP and are the standard treatment. CAP contributes significantly to antibiotic use, which is associated with the development of bacterial resistance and side-effects. Several studies have been published concerning treatment for CAP. Available data arises mainly hospitalized patients studies. This is an update of our 2004 Cochrane Review.

OBJECTIVES

To summarize current evidence from randomized controlled trials (RCTs) concerning the efficacy of different antibiotic treatments for CAP in participants older than 12.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2009, issue 1) which contains the Cochrane Acute Respiratory Infections Group's Specialized Register; MEDLINE (January 1966 to February week 2, 2009), and EMBASE (January 1974 to February 2009).

SELECTION CRITERIA

RCTs in which one or more antibiotics were tested for the treatment of CAP in ambulatory adolescents or adults. Studies testing one or more antibiotics and reporting the diagnostic criteria as well as the clinical outcomes achieved, were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors (LMB, TJMV) independently assessed study reports in the first publication. In this update, LMB performed study selection, which was checked by TJMV and MMK. Study authors were contacted to resolve any ambiguities in the study reports. Data were compiled and analyzed. Differences between review authors were resolved by discussion and consensus.

MAIN RESULTS

Six RCTs assessing five antibiotic pairs (1857 participants aged 12 years and older diagnosed with CAP) were included. The study quality was generally good, with some differences in the extent of the reporting. A variety of clinical, radiological and bacteriological diagnostic criteria and outcomes were reported. Overall, there was no significant difference in the efficacy of the various antibiotics.

AUTHORS' CONCLUSIONS

Currently available evidence from RCTs is insufficient to make evidence-based recommendations for the choice of antibiotic to be used for the treatment of CAP in ambulatory patients. Pooling of study data was limited by the very low number of studies assessing the same antibiotic pairs. Individual study results do not reveal significant differences in efficacy between various antibiotics and antibiotic groups. Multi-drug comparisons using similar administration schedules are needed to provide the evidence necessary for practice recommendations.

Efficacy of short-course antibiotic regimens for community-acquired pneumonia: a meta-analysis

PURPOSE

There is little consensus on the most appropriate duration of antibiotic treatment for community-acquired pneumonia. The goal of this study is to systematically review randomized controlled trials comparing short-course and extended-course antibiotic regimens for community-acquired pneumonia.

METHODS

We searched MEDLINE, Embase, and CENTRAL, and reviewed reference lists from 1980 through June 2006. Studies were included if they were randomized controlled trials that compared short-course (7 days or less) versus extended-course (>7 days) antibiotic monotherapy for community-acquired pneumonia in adults. The primary outcome measure was failure to achieve clinical improvement.

RESULTS

We found 15 randomized controlled trials matching our inclusion and exclusion criteria comprising 2796 total subjects. Short-course regimens primarily studied the use of azithromycin (n=10), but trials examining beta-lactams (n=2), fluoroquinolones (n=2), and ketolides (n=1) were found as well. Of the extended-course regimens, 3 studies utilized the same antibiotic, whereas 9 involved an antibiotic of the same class. Overall, there was no difference in the risk of clinical failure between the short-course and extended-course regimens (0.89, 95% confidence interval [CI], 0.78-1.02). In addition, there were no differences in the risk of mortality (0.81, 95% CI, 0.46-1.43) or bacteriologic eradication (1.11, 95% CI, 0.76-1.62). In subgroup analyses, there was a trend toward favorable clinical efficacy for the short-course regimens in all antibiotic classes (range of relative risk, 0.88-0.94).

CONCLUSIONS

The available studies suggest that adults with mild to moderate community-acquired pneumonia can be safely and effectively treated with an antibiotic regimen of 7 days or less. Reduction in patient exposure to antibiotics may limit the increasing rates of antimicrobial drug resistance, decrease cost, and improve patient adherence and tolerability.

Dyspnea

When evaluating a dyspneic patient in the office, a quick initial assessment of the airway, breathing, and circulation, while gathering a brief history and focused physical examination are necessary. Most often, an acute cardiopulmonary disorder, such as CHF, cardiac ischemia, pneumonia, asthma, or COPD exacerbation, can be identified and treated. Stable patients who improve can be sent home, but those in acute distress with unstable or impending unstable conditions need to be transferred emergently to definitive care. Because of the difficult logistics involved in attempting to work up an outpatient for new onset of SOB, some patients will need to be transferred to the nearest ED for a definitive diagnosis.

Procalcitonin-guided antibiotic use versus a standard approach for acute respiratory tract infections in primary care: study protocol for a randomised controlled trial and baseline characteristics of participating general practitioners [ISRCTN73182671]

BACKGROUND

Acute respiratory tract infections (ARTI) are among the most frequent reasons for consultations in primary care. Although predominantly viral in origin, ARTI often lead to the prescription of antibiotics for ambulatory patients, mainly because it is difficult to distinguish between viral and bacterial infections. Unnecessary antibiotic use, however, is associated with increased drug expenditure, side effects and antibiotic resistance. A novel approach is to guide antibiotic therapy by procalcitonin (ProCT), since serum levels of ProCT are elevated in bacterial infections but remain lower in viral infections and inflammatory diseases. The aim of this trial is to compare a ProCT-guided antibiotic therapy with a standard approach based on evidence-based guidelines for patients with ARTI in primary care.

METHODS/DESIGN

This is a randomised controlled trial in primary care with an open intervention. Adult patients judged by their general practitioner (GP) to need antibiotics for ARTI are randomised in equal numbers either to standard antibiotic therapy or to ProCT-guided antibiotic therapy. Patients are followed-up after 1 week by their GP and after 2 and 4 weeks by phone interviews carried out by medical students blinded to the goal of the trial. Exclusion criteria for patients are antibiotic use in the previous 28 days, psychiatric disorders or inability to give written informed consent, not being fluent in German, severe immunosuppression, intravenous drug use, cystic fibrosis, active tuberculosis, or need for immediate hospitalisation. The primary endpoint is days with restrictions from ARTI within 14 days after randomisation. Secondary outcomes are antibiotic use in terms of antibiotic prescription rate and duration of antibiotic treatment in days, days off work and days with side-effects from medication within 14 days, and relapse rate from the infection within 28 days after randomisation.

DISCUSSION

We aim to include 600 patients from 50 general practices in the Northwest of Switzerland. Data from the registry of the Swiss Medical Association suggests that our recruited GPs are representative of all eligible GPs with respect to age, proportion of female physicians, specialisation, years of postgraduate training and years in private practice.

Empiric treatment of ambulatory community-acquired pneumonia: always include treatment for atypical agents

There are no data from proper studies to answer whether it is necessary to include antibiotics that are active against atypical pneumonia agents as part of the empiric therapy of CAP. Until such data are available, clinical judgment and severity of the pneumonic illness are the best guides to empiric antimicrobial therapy.