Treatment of severe pneumonia in hospitalised patients. Results of a multicentre trial comparing i.v. ciprofloxacin with imipenem/cilastatin

Empiric antibiotic coverage of atypical pathogens for community-acquired pneumonia in hospitalized adults

BACKGROUND

Community-acquired pneumonia (CAP) is caused by various pathogens, traditionally divided into 'typical' and 'atypical'. Initial antibiotic treatment of CAP is usually empirical, customarily covering both typical and atypical pathogens. To date, no sufficient evidence exists to support this broad coverage, while limiting coverage is bound to reduce toxicity, resistance and expense.

OBJECTIVES

The main objective was to estimate the mortality and proportion with treatment failure using regimens containing atypical antibiotic coverage compared to those that had typical coverage only. Secondary objectives included the assessment of adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) Issue 3, 2012 which includes the Acute Respiratory Infection Group's Specialized Register, MEDLINE (January 1966 to April week 1, 2012) and EMBASE (January 1980 to April 2012).

SELECTION CRITERIA

Randomized controlled trials (RCTs) of adult patients hospitalized due to CAP, comparing antibiotic regimens with atypical coverage (quinolones, macrolides, tetracyclines, chloramphenicol, streptogramins or ketolides) to a regimen without atypical antibiotic coverage.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data from included trials. We estimated risk ratios (RRs) with 95% confidence intervals (CIs). We assessed heterogeneity using a Chi(2) test.

MAIN RESULTS

We included 28 trials, encompassing 5939 randomized patients. The atypical antibiotic was administered as monotherapy in all but three studies. Only one study assessed a beta-lactam combined with a macrolide compared to the same beta-lactam. There was no difference in mortality between the atypical arm and the non-atypical arm (RR 1.14; 95% CI 0.84 to 1.55), RR < 1 favors the atypical arm. The atypical arm showed an insignificant trend toward clinical success and a significant advantage to bacteriological eradication, which disappeared when evaluating methodologically high quality studies alone. Clinical success for the atypical arm was significantly higher for Legionella pneumophilae (L. pneumophilae) and non-significantly lower for pneumococcal pneumonia. There was no significant difference between the groups in the frequency of (total) adverse events, or those requiring discontinuation of treatment. However, gastrointestinal events were less common in the atypical arm (RR 0.70; 95% CI 0.53 to 0.92). Although the trials assessed different antibiotics, no significant heterogeneity was detected in the analyses.

AUTHORS' CONCLUSIONS

No benefit of survival or clinical efficacy was shown with empirical atypical coverage in hospitalized patients with CAP. This conclusion relates mostly to the comparison of quinolone monotherapy to beta-lactams. Further trials, comparing beta-lactam monotherapy to the same combined with a macrolide, should be performed.

Imipenem resistance of Pseudomonas in pneumonia: a systematic literature review

Background

Pneumonia, and particularly nosocomial (NP) and ventilator-associated pneumonias (VAP), results in high morbidity and costs. NPs in particular are likely to be caused by Pseudomonas aeruginosa (PA), ~20% of which in observational studies are resistant to imipenem. We sought to identify the burden of PA imipenem resistance in pneumonia.

Methods

We conducted a systematic literature review of randomized controlled trials (RCT) of imipenem treatment for pneumonia published in English between 1993 and 2008. We extracted study, population and treatment characteristics, and proportions caused by PA. Endpoints of interest were: PA resistance to initial antimicrobial treatment, clinical success, microbiologic eradication and on-treatment emergence of resistance of PA.

Results

Of the 46 studies identified, 20 (N = 4,310) included patients with pneumonia (imipenem 1,667, PA 251; comparator 1,661, PA 270). Seven were double blind, and 7 included US data. Comparator arms included a β-lactam (17, [penicillin 6, carbapenem 4, cephalosporin 7, monobactam 1]), aminoglycoside 2, vancomycin 1, and a fluoroquinolone 5; 5 employed double coverage. Thirteen focused exclusively on pneumonia and 7 included pneumonia and other diagnoses. Initial resistance was present in 14.6% (range 4.2-24.0%) of PA isolates in imipenem and 2.5% (range 0.0-7.4%) in comparator groups. Pooled clinical success rates for PA were 45.2% (range 0.0-72.0%) for imipenem and 74.9% (range 0.0-100.0%) for comparator regimens. Microbiologic eradication was achieved in 47.6% (range 0.0%-100.0%) of isolates in the imipenem and 52.8% (range 0.0%-100.0%) in the comparator groups. Resistance emerged in 38.7% (range 5.6-77.8%) PA isolates in imipenem and 21.9% (range 4.8-56.5%) in comparator groups.

Conclusions

In the 15 years of RCTs of imipenem for pneumonia, PA imipenem resistance rates are high, and PA clinical success and microbiologic eradication rates are directionally lower for imipenem than for comparators. Conversely, initial and treatment-emergent resistance is more likely with the imipenem than the comparator regimens.

Empiric antibiotic coverage of atypical pathogens for community acquired pneumonia in hospitalized adults

BACKGROUND

Community acquired pneumonia (CAP) is caused by various pathogens, traditionally divided to 'typical' and 'atypical'. Initial antibiotic treatment of CAP is usually empirical, customarily covering both typical and atypical pathogens. To date, no sufficient evidence exists to support this broad coverage, while limiting coverage is bound to reduce toxicity, resistance and expense.

OBJECTIVES

To assess the efficacy and need of adding antibiotic coverage for atypical pathogens in hospitalized patients with CAP, in terms of mortality and successful treatment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1) which includes the Acute Respiratory Infection Group's specialized register; MEDLINE (January 1966 to March 2007); and EMBASE (January 1980 to January 2007).

SELECTION CRITERIA

Randomized trials of adult patients hospitalized due to CAP, comparing antibiotic regimens with atypical antibiotic coverage to a regimen without atypical antibiotic coverage.

DATA COLLECTION AND ANALYSIS

Two review authors independently appraised the quality of each trial and extracted the data from included trials. Relative risks (RR) with 95% confidence intervals (CI) were estimated, assuming an intention-to-treat (ITT) basis for the outcome measures.

MAIN RESULTS

Twenty five trials were included, encompassing 5244 randomized patients. There was no difference in mortality between the atypical arm and the non-atypical arm (RR 1.15; 95% CI 0.85 to 1.56). The atypical arm showed an insignificant trend toward clinical success and a significant advantage to bacteriological eradication, which disappeared when evaluating methodologically high-quality studies alone. Clinical success for the atypical arm was significantly higher for Legionella pneumophilae (L. pneumophilae) and non-significantly lower for pneumococcal pneumonia. There was no significant difference between the groups in the frequency of (total) adverse events, or those requiring discontinuation of treatment. However, gastrointestinal events were more common in the non-atypical arm (RR 0.73, 95% CI 0.54 to 0.99). All but two included trials compared a single atypical antibiotic to a beta-lactam, while no trials assessing the addition of an atypical antibiotic to a beta-lactam were identified.

AUTHORS' CONCLUSIONS

No benefit of survival or clinical efficacy was shown to empirical atypical coverage in hospitalized patients with CAP. This conclusion relates mostly to the comparison of quinolone monotherapy to beta-lactams (BL) or cephalosporins. Further trials, comparing BL or cephalosporins therapy to BL or cephalosporins combined with a macrolide in this population, using mortality as its primary outcome, should be performed.

Empiric antibiotic coverage of atypical pathogens for community acquired pneumonia in hospitalized adults

BACKGROUND

Community acquired pneumonia (CAP) is caused by various pathogens, traditionally divided to 'typical' and 'atypical'. Initial antibiotic treatment of CAP is usually empirical, customarily covering both typical and atypical pathogens. To date, no sufficient evidence exists to support this broad coverage, while limiting coverage is bound to reduce toxicity, resistance and expense.

OBJECTIVES

Assess the efficacy and need of adding antibiotic coverage for atypical pathogens in hospitalized patients with CAP, in terms of mortality and successful treatment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005) which includes the Acute Respiratory Infection Group's specialized register; MEDLINE (January 1966 to January Week 2 2005); and EMBASE (January 1980 to January Week 2 2005).

SELECTION CRITERIA

Randomized trials of adult patients hospitalized due to CAP, comparing antibiotic regimens with atypical antibiotic coverage to a regimen without atypical antibiotic coverage.

DATA COLLECTION AND ANALYSIS

Two reviewers independently appraised the quality of each trial and extracted the data from included trials. Relative risks (RR) with 95% confidence intervals (CI) were estimated, assuming an intention-to-treat (ITT) basis for the outcome measures.

MAIN RESULTS

Twenty four trials were included, encompassing 5015 randomized patients. There was no difference in mortality between the atypical arm and the non-atypical arm (RR 1.13; 95% CI 0.82 to 1.54). The atypical arm showed an insignificant trend toward clinical success and a significant advantage to bacteriological eradication, which disappeared when evaluating methodologically high-quality studies alone. Clinical success for the atypical arm was significantly higher for Legionella pneumophilae (L. pneumophilae) and non-significantly lower for pneumococcal pneumonia. There was no significant difference between the groups in the frequency of (total) adverse events, or those requiring discontinuation of treatment. However, gastrointestinal events were more common in the non-atypical arm (RR 0.73, 95% CI 0.54 to 0.99).

AUTHORS' CONCLUSIONS

No benefit of survival or clinical efficacy was shown to empirical atypical coverage in hospitalized patients with CAP. This conclusion relates mostly to the comparison of quinolone monotherapy to non-atypical monotherapy. Further trials, comparing beta-lactam (BL) or cephalosporin therapy to BL or cephalosporin combined with a macrolide in this population, using mortality as its primary outcome, should be performed.