Antibiotics for pneumonia therapy

Azithromycin for acute lower respiratory tract infections

BACKGROUND

Acute lower respiratory tract infections (LRTI) range from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Approximately five million people die from acute respiratory tract infections annually. Among these, pneumonia represents the most frequent cause of mortality, hospitalisation and medical consultation. Azithromycin is a macrolide antibiotic, structurally modified from erythromycin and noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae).

OBJECTIVES

To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication.

SEARCH METHODS

We searched CENTRAL (2014, Issue 10), MEDLINE (January 1966 to October week 4, 2014) and EMBASE (January 1974 to November 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs, comparing azithromycin to amoxycillin or amoxycillin/clavulanic acid in participants with clinical evidence of an acute LRTI, such as acute bronchitis, pneumonia and acute exacerbation of chronic bronchitis.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed all potential studies identified from the searches for methodological quality. We extracted and analysed relevant data separately. We resolved discrepancies through discussion. We initially pooled all types of acute LRTI in the meta-analyses. We investigated the heterogeneity of results using the forest plot and Chi(2) test. We also used the index of the I(2) statistic to measure inconsistent results among trials. We conducted subgroup and sensitivity analyses.

MAIN RESULTS

We included 16 trials involving 2648 participants. We were able to analyse 15 of the trials with 2496 participants. The pooled analysis of all the trials showed that there was no significant difference in the incidence of clinical failure on about days 10 to 14 between the two groups (risk ratio (RR), random-effects 1.09; 95% confidence interval (CI) 0.64 to 1.85). A subgroup analysis in trials with acute bronchitis participants showed significantly lower clinical failure in the azithromycin group compared to amoxycillin or amoxyclav (RR random-effects 0.63; 95% CI 0.45 to 0.88). A sensitivity analysis showed a non-significant reduction in clinical failure in azithromycin-treated participants (RR 0.55; 95% CI 0.25 to 1.21) in three adequately concealed studies, compared to RR 1.32; 95% CI 0.70 to 2.49 in 12 studies with inadequate concealment. Twelve trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.95; 95% CI 0.87 to 1.03). The reduction of adverse events in the azithromycin group was RR 0.76 (95% CI 0.57 to 1.00).

AUTHORS' CONCLUSIONS

There is unclear evidence that azithromycin is superior to amoxycillin or amoxyclav in treating acute LRTI. In patients with acute bronchitis of a suspected bacterial cause, azithromycin tends to be more effective in terms of lower incidence of treatment failure and adverse events than amoxycillin or amoxyclav. However, most studies were of unclear methodological quality and had small sample sizes; future trials of high methodological quality and adequate sizes are needed.

Azithromycin for acute lower respiratory tract infections

BACKGROUND

Acute lower respiratory tract infections (LRTI) range from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Approximately five million people die of acute respiratory tract infections annually. Among these, pneumonia represents the most frequent cause of mortality, hospitalization and medical consultation. Azithromycin is a new macrolide antibiotic, structurally modified from erythromycin and noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae).

OBJECTIVES

To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007 Issue 2), MEDLINE (January 1966 to July 2007), and EMBASE (January 1974 to July 2007).

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials, comparing azithromycin to amoxycillin or amoxycillin/clavulanic acid in participants with clinical evidence of acute LRTI: acute bronchitis, pneumonia, and acute exacerbation of chronic bronchitis were studied.

DATA COLLECTION AND ANALYSIS

The criteria for assessing study quality were generation of allocation sequence, concealment of treatment allocation, blinding, and completeness of the trial. All types of acute LRTI were initially pooled in the meta-analyses. The heterogeneity of results was investigated by the forest plot and Chi-square test. Index of I-square (I(2)) was also used to measure inconsistent results among trials. Subgroup and sensitivity analyses were conducted.

MAIN RESULTS

Fifteen trials were analysed. The pooled analysis of all trials showed that there was no significant difference in the incidence of clinical failure on about day 10 to 14 between the two groups (relative risk (RR), random-effects 1.09; 95% confidence interval (CI) 0.64 to 1.85). Sensitivity analysis showed a reduction of clinical failure in azithromycin-treated participants (RR 0.55; 95% CI 0.25 to 1.21) in three adequately concealed studies, compared to RR 1.32; 95% CI 0.70 to 2.49 in 12 studies with inadequate concealment. Twelve trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.95; 95% CI 0.87 to 1.03). The reduction of adverse events in the azithromycin group was RR 0.76 (95% CI 0.57 to 1.00).

AUTHORS' CONCLUSIONS

There is unclear evidence that azithromycin is superior to amoxicillin or amoxyclav in treating acute LRTI. In patients with acute bronchitis of a suspected bacterial cause, azithromycin tends to be more effective in terms of lower incidence of treatment failure and adverse events than amoxicillin or amoxyclav. Future trials of high methodological quality are needed.

Implication of clinical pathway care for community-acquired pneumonia in a community hospital: early switch from an intravenous beta-lactam plus a macrolide to an oral respiratory fluoroquinolone

OBJECTIVE

The effect of clinical pathway (CP) care and early switch from intravenous to oral antibiotics therapy on community-acquired pneumonia (CAP) has been well documented. However, limited studies have evaluated the effects of CP on reducing time taken for attaining clinical stability and duration of antibiotics prescriptions. This study was aimed to investigate the use of a CP and its implication for CAP in a community hospital.

METHODS

We conducted a retrospective cohort study of CAP patients hospitalized between November 2005 and January 2007. The patients were divided into two groups, those for whom CP was adopted and those for whom CP was not adopted on admission. We compared the outcomes of three risk classes assessed using the severity scoring system (A-DROP). CP included switching from an intravenous beta-lactam plus a macrolide to an oral respiratory fluoroquinolone, when the patients exhibited risk factors for drug-resistant pneumococci.

RESULTS

One hundred thirty-five patients were evaluated, and sixty received CP care. Patients in the CP group had a lower A-DROP score. Although clinical cure proportions were similar, the CP group in the mild and moderate classes (A-DROP score, <or=2) required significantly less time to achieve clinical stability and had a reduced duration of total antibiotics prescriptions, length of hospital stay, and hospital charges. These effects were absent in the severe class.

CONCLUSION

Implementation of this CP would lead to effective care, may serve to reduce time for attaining clinical stability and reduce the use of unnecessary antibiotics without worsening clinical outcomes in mild and moderate CAP.

Azithromycin for acute lower respiratory tract infections

BACKGROUND

The spectrum of acute lower respiratory tract infection ranges from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Annually approximately five million people die of acute respiratory tract infections. Among these, pneumonia represents the most frequent cause of mortality, hospitalization and medical consultation. Azithromycin is a new macrolide antibiotic, structurally modified from erythromycin and is noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae).

OBJECTIVES

To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2003), MEDLINE (January 1966 to January Week 3, 2004), and EMBASE (January 1988 to 2003).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials, which compared azithromycin to amoxycillin or amoxycillin/clavulanic acid in patients with clinical evidence of acute LRTI: acute bronchitis, pneumonia, and acute exacerbation of chronic bronchitis were studied.

DATA COLLECTION AND ANALYSIS

The criteria for assessing study quality were generation of allocation sequence, concealment of treatment allocation, blinding, and completeness of the trial. All types of acute lower respiratory tract infections were initially pooled in the meta-analyses. Funnel plot was used to examine publication bias. The heterogeneity of results was investigated by the forest plot and Chi-square test. Index of I(2) was also used to measure inconsistency results among trials. Subgroup analysis was conducted for age, types of respiratory tract infection and types of antibiotic in control groups. Sensitivity analysis was conducted under the condition of trial size and concealment of treatment allocation.

MAIN RESULTS

Fourteen trials with 2,521 enrolled patients used 2,416 patients in the analysis. A total of 1,350 patients received azithromycin and 1,066 received amoxicillin or amoxicillin-clavulanic acid. The pooled analysis of all trials showed that there was no significant difference in the incidence of clinical failure on about day 10 to 14 after therapy started between the two groups (relative risk (RR) (random effects) 0.96; 95% CI 0.58 to 1.57). Sensitivity analysis showed that a reduction of clinical failure in azithromycin-treated patients (RR 0.52; 95% CI 0.24 to 1.12) in three adequately concealed studies, compared to RR 1.14 (95% CI 0.62 to 2.08) in eleven studies with inadequate concealment. Eleven trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.98; 95% CI 0.91 to 1.07). The reduction of adverse events in azithromycin group was RR 0.75 (95% CI 0.56 to 1.00).

REVIEWERS' CONCLUSIONS

There is unclear evidence that azithromycin is superior to amoxicillin or amoxicillin-clavulanic acid in treating acute LRTI. Future trials with high methodological quality are needed.

Cefepime versus ceftazidime for treatment of pneumonia

Consecutive patients with pneumonia, treated with cefepime (n = 66) or ceftazidime (n = 132), were evaluated in a retrospective, observational study. There was no significant difference between the two treatment groups with respect to age, underlying diseases, acute physical and chronic health evaluation score, intensive care unit admission, presence of sepsis, community or hospital acquisition, causative organism, duration of therapy, death, cure or improvement in infection, adverse events, superinfections, presence of vancomycin-resistant enterococcus (VRE) and resistance to therapy. Post-therapy hospitalization (days) and vancomycin co-administration were significantly lower, and time to vancomycin initiation significantly higher, in the cefepime compared with the ceftazidime group. The results suggest a trend towards less resistance on therapy, less VRE, reduced vancomycin use and shorter post-therapy hospitalization in patients treated with cefepime compared with ceftazidime. The clinical outcomes for hospitalized patients treated for serious pneumonia were similar between the two groups.

Antibiotics

This chapter discusses the bacterial pathogens that cause infective exacerbations, trials of antimicrobial therapy, individual antimicrobial agents, and guidelines for their use in the treatment of both asthma and chronic obstructive pulmonary disease (COPD). The relationship between respiratory tract infection, especially viral infection, and exacerbations of airway diseases is very well established. However, research is required to find new ways to distinguish between the colonization and infective exacerbations of COPD to gain a better understanding of the role of infection in the disease. With advances in molecular biology, the antigenic structures of bacteria and the evaluation of the antibody response to antigens can become the basis for identifying an acute exacerbation of COPD (AECB). Most clinical trials of antibiotics were performed for licensing, and patients with pathogens resistant to different antimicrobials were excluded. Future studies of new antimicrobials should examine clinical efficacy more stringently based on a classification system that would help select patients most likely to benefit from an antibiotic. These studies should also include well-defined prospective economic analyses and quality-of-life assessment to ascertain the cost utility of the antibiotic in question.

Impact of Antimicrobial Resistance on the Treatment of Invasive Pneumococcal Infections

Infectious diseases, such as pneumococcal pneumonia, which were almost invariably lethal in the pre-antibiotic era, caused radically less mortality with the advent of antimicrobial chemotherapy. However, the use, misuse, and abuse of these agents have led to the emergence of antimicrobial resistance. In the past, pneumococci were all exquisitely sensitive to penicillin G. By the late 1960s, penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) was being described. Since then, this problem has achieved epidemic proportions in many areas of the world, including the United States. Many experts no longer consider penicillin an acceptable therapy for patients suspected of having invasive pneumococcal disease, especially if the central nervous system (CNS) is involved. Recommendations for therapy are based on theoretical concerns, in vitro susceptibility testing, animal data, and a few, scattered reports of penicillin failure in patients with invasive disease.

Clarithromycin in the management of community-acquired pneumonia

OBJECTIVE

To review the epidemiology and diagnosis of community-acquired pneumonia (CAP) and examine factors that influence the choice of empiric antimicrobial therapy.

BACKGROUND

CAP remains a common disease with substantial associated morbidity and mortality. Outpatient management of patients with CAP has become increasingly complex because of the availability of newer antimicrobial agents, evolving patterns of resistance, and the increasing recognition of atypical pathogens. Although Streptococcus pneumoniae remains a commonly encountered pathogen, the development and increasing prevalence of antibiotic resistance has become an area of concern, especially in outpatients. The newer macrolide antimicrobial drugs-clarithromycin and azithromycin-are effective against commonly encountered pathogens, are well tolerated, and have an established tolerability profile, although the low serum levels achieved by azithromycin hinder its use in patients with suspected bacteremia.

METHODS

A MEDLINE search was performed of English-language articles published from 1990 to 2000 on the treatment of CAP. This article reviews the treatment of CAP, with emphasis on the use of clarithromycin.

CONCLUSION

Although laboratory surveillance studies have reported macrolide-resistant S. pneumoniae, recent evidence defining the mechanism of this resistance, coupled with the pharmacokinetic properties of the macrolide agents, suggests that the actual rate of clinical macrolide resistance is low.

Antibiotic therapy for community-acquired pneumonia

This article takes a broad perspective of community-acquired pneumonia (CAP). The arguments and data that support or refute the current approaches to initial antimicrobial treatment of CAP as outlined in the American Thoracic Society and Infectious Disease Society of America documents are provided. The complex issues involved in the decision of how to properly treat CAP are addressed.