Treatment of community-acquired pneumonia. A multicenter, double-blind, randomized study comparing clarithromycin with erythromycin. Canada-Sweden Clarithromycin-Pneumonia Study Group

Efficacy of erythromycin compared to clarithromycin and azithromycin in adults or adolescents with community-acquired pneumonia: A Systematic Review and meta-analysis of randomized controlled trials

BACKGROUND

It is debatable whether erythromycin has similar efficacy to other macrolides in treating community-acquired pneumonia (CAP). The aim of this meta-analysis is to compare the efficacy of erythromycin with clarithromycin and azithromycin.

METHODS

We performed this meta-analysis of randomized controlled trials (RCTs) of adults or adolescents with CAP which compared the efficacy of erythromycin monotherapy to either azithromycin or clarithromycin. We searched PubMed and EMBASE and Cochrane Library databases and three clinical trial registries up to November 02, 2021. We evaluated heterogeneity and used random-effects models to perform risk ratios with 95% confidence intervals.

RESULTS

We included four RCTs (total of 472 patients), which compared the clinical efficacy of erythromycin versus clarithromycin. No studies comparing monotherapy of erythromycin versus azithromycin were found. Erythromycin use was associated with significantly lower rates of clinical success (RR, 0.79; 95% CI, 0.64 to 0.98; P-value = 0.033; I² = 20.27%), clinical cure (RR,0.67; 95% CI, 0.48 to 0.92; P-value = 0.014; I² = 8.75%), and radiological success (RR, 0.84; 95% CI, 0.71 to 0.996; P-value = 0.045; I² = 20.12%) than clarithromycin.

CONCLUSION

Erythromycin is less effective than clarithromycin as empiric treatment of CAP in adults and adolescents. Because of this and the higher rate of adverse reactions, erythromycin should not be used in the majority of CAP patients when azithromycin and clarithromycin are available.

Efficacy of different antibiotics in treatment of children with respiratory mycoplasma infection

BACKGROUND

Respiratory infections in children are common pediatric diseases caused by pathogens that invade the respiratory system. Children are considerably susceptible to Mycoplasma pneumoniae infection. There has been widespread clinical attention on treatment strategies for this disease.

AIM

To analyze the clinical efficacy of different antibiotics in treating pediatric respiratory mycoplasma infections.

METHODS

We included 106 children with a confirmed diagnosis of respiratory mycoplasma infection who were admitted to our hospital from April 2017 to July 2019 and grouped them using a random number table. Among them, 53 children each received clarithromycin or erythromycin. The clinical efficacy of both drugs was evaluated and compared. We performed the multiplex polymerase chain reaction (MP-PCR) test and determined the MP-PCR negative rate in children after the end of the treatment course. We compared the incidence of toxic and side effects, including nausea, diarrhea, and abdominal pain; further, we recorded the length of hospitalization, antipyretic time, and drug costs. Additionally, we evaluated and compared the compliance of the children during treatment.

RESULTS

The erythromycin group showed a significantly higher total effective rate of clinical treatment than the clarithromycin group. MP-PCR test results showed that the clarithromycin group had a significantly higher MP-PCR negative rate than the erythromycin group. Moreover, children in the clarithromycin group had shorter fever time, shorter hospital stays, and lower drug costs than those in the erythromycin group. The clarithromycin group had a significantly higher overall drug adherence rate than the erythromycin group. The incidence of toxic and side effects was significantly lower in the clarithromycin group than in the erythromycin group (P < 0.05).

CONCLUSION

Our findings indicate that clarithromycin has various advantages over erythromycin, including higher application safety, stronger mycoplasma clearance, and higher medication compliance in children; therefore, it can be actively promoted.

Systematic review and meta-analysis of the safety of erythromycin compared to clarithromycin in adults and adolescents with pneumonia

Macrolides are recommended for the treatment of community-acquired pneumonia (CAP). It is debatable whether erythromycin is associated with more adverse drug reactions (ADRs) compared to clarithromycin, and both are recommended in clinical practice guidelines. This meta-analysis aim is to compare ADRs in CAP patients treated with erythromycin versus clarithromycin. Two investigators independently searched PubMed, EMBASE and Cochrane Library databases through Feb 07, 2019. Randomized-controlled trials (RCTs) comparing ADRs of monotherapy with erythromycin versus with clarithromycin in adults or adolescents with CAP were included. We estimated risk ratios (RRs) with 95% confidence intervals (CIs) using random-effects models and evaluated heterogeneity (I²). Bias risk was assessed using the Cochrane risk of bias tool for RCTs. Five RCTs (total of 693 patients) were included. A significantly higher discontinuation rate due to ADRs was found with erythromycin compared with clarithromycin (RR, 4.347; 95% CI, 2.506-7.539; p < 0.001; I²=0%). Overall, ADRs occurred more significantly with erythromycin compared with clarithromycin (RR, 1.773; 95% CI, 1.423-2.209; p < 0.001; I²=0%). Gastrointestinal (GI) ADRs were higher with erythromycin (RR, 2.678; 95% CI, 1.791-4.006; p < 0.001; I²=5.835%). Restriction of analyses to double-blind RCTs did not change our findings. Based on meta-analysis of RCTs in adults and adolescents with CAP, erythromycin results in more overall ADRs and GI ADRs, as well as a higher rate of discontinuation due to ADRs. Therefore, given that erythromycin is not more effective than clarithromycin, erythromycin should not be selected unless other macrolides cannot be used.

In vitro activity and pharmacodynamic/pharmacokinetic parameters of clarithromycin and azithromycin: why they matter in the treatment of respiratory tract infections

Clarithromycin and azithromycin are second-generation macrolides established and widely used for treating a range of upper and lower respiratory tract infections. Extensive clinical trials data indicate that these drugs are highly effective in these applications and broadly comparable in their clinical and microbiological effectiveness. However, consideration of pharmacokinetic, metabolic, and tissue-penetration data, including the significant antibacterial activity of the metabolite 14-hydroxy-clarithromycin, plus the findings of pharmacodynamic modeling, provide evidence that the long half-life and lower potency of azithromycin predispose this agent to select for resistant isolates. Comparison of the "mutant-prevention concentrations" of clarithromycin and azithromycin, and examination of large-scale epidemiological data from Canada, also support the view that these drugs differ materially in their propensity to promote resistance among bacterial strains implicated in common respiratory infections, and that clarithromycin may offer important advantages over azithromycin that should be considered when choosing a macrolide to treat these conditions.

Clarithromycin Plus Intravenous Immunoglobulin Therapy Can Reduce the Relapse Rate of Kawasaki Disease: A Phase 2, Open-Label, Randomized Control Study

Background

We previously reported that biofilms and innate immunity contribute to the pathogenesis of Kawasaki disease. Therefore, we aimed to assess the efficacy of clarithromycin, an antibiofilm agent, in patients with Kawasaki disease.

Methods and Results

We conducted an open‐label, multicenter, randomized, phase 2 trial at 8 hospitals in Japan. Eligible patients included children aged between 4 months and 5 years who were enrolled between days 4 and 8 of illness. Participants were randomly allocated to receive either intravenous immunoglobulin (IVIG) or IVIG plus clarithromycin. The primary end point was the duration of fever after the initiation of IVIG treatment. Eighty‐one eligible patients were randomized. The duration of the fever did not differ between the 2 groups (mean±SD, 34.3±32.4 and 31.1±31.1 hours in the IVIG plus clarithromycin group and the IVIG group, respectively [P=0.66]). The relapse rate of patients in the IVIG plus clarithromycin group was significantly lower than that in the IVIG group (12.5% versus 30.8%, P=0.046). No serious adverse events occurred during the study period. In a post hoc analysis, the patients in the IVIG plus clarithromycin group required significantly shorter mean lengths of hospital stays than those in the IVIG group (8.9 days versus 10.3 days, P=0.049).

Conclusions

Although IVIG plus clarithromycin therapy failed to shorten the duration of fever, it reduced the relapse rate and shortened the duration of hospitalization in patients with Kawasaki disease.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000015437.

Antibiotics for community-acquired lower respiratory tract infections secondary to Mycoplasma pneumoniae in children

Background. Mycoplasma pneumoniae (M. pneumoniae) is widely recognised as an important cause of community-acquired lower respiratory tract infection (LRTI) in children. Pulmonary manifestations are typically tracheobronchitis or pneumonia but M. pneumoniae is also implicated in wheezing episodes in both asthmatic and non-asthmatic individuals. Although antibiotics are used to treat LRTIs, are view of several major textbooks offers conflicting advice for using antibiotics in the management of M. pneumoniae LRTI in children.Objectives To determine whether antibiotics are effective in the treatment of childhood LRTI secondary to M. pneumoniae infections acquired in the community.Search methods We searched CENTRAL (2014, Issue 3), MEDLINE (1966 to July week 4, 2014), EMBASE (1980 to July, 2014), and both WHOICTRP and ClinicalTrials.gov (13 August 2014).Selection criteria Randomised controlled trials (RCTs) comparing antibiotics commonly used for treating M. pneumoniae (i.e. macrolide, tetracycline or quinolone classes) versus placebo, or antibiotics from any other class in the treatment of children under 18 years of age with community acquired LRTI secondary to M. pneumoniae.Data collection and analysis The review authors independently selected trials for inclusion and assessed methodological quality. We extracted and analysed relevant data separately and resolved disagreements by consensus.Main results A total of 1912 children were enrolled from seven studies. Data interpretation was limited by the inability to extract data that referred to children with M. pneumoniae. In most studies, clinical response did not differ between children randomised to a macrolide antibiotic and children randomised to a non-macrolide antibiotic. In one controlled study (of children with recurrent respiratory infections, whose acute LRTI was associated with Mycoplasma, Chlamydia or both, by polymerase chain reaction and/or paired sera) 100% of children treated with azithromycin had clinical resolution of their illness compared to 77% not treated with azithromycin at one month. Authors' conclusions There is insufficient evidence to draw any specific conclusions about the efficacy of antibiotics for this condition in children (although one trial suggests macrolides may be efficacious in some children with LRTI secondary to Mycoplasma). The use of antibiotics has to be balanced with possible adverse events. There is still a need for high quality, double-blinded RCTs to assess the efficacy and safety of antibiotics for LRTI secondary to M. pneumoniae in children.

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.

Comparison of Clarithromycin and Amoxicillin/Clavulanic Acid for Community-Acquired Pneumonia in an Era of Drug-Resistant Streptococcus pneumoniae

OBJECTIVE

To compare the safety and efficacy of clarithromycin and amoxicillin/clavulanic acid in patients with community-acquired pneumonia due to penicillin-resistant and/or macrolide-resistant Streptococcus pneumoniae, by selecting clinical investigators who practice in study populations from geographic areas in which a high incidence of resistant strains is reported by surveillance.

DESIGN AND SETTING

Prospective, randomised, investigator-blinded, multicentre study conducted in 45 sites in primary-care and referral centre settings.

PATIENTS AND INTERVENTIONS

327 ambulatory patients diagnosed with radio-graphically confirmed community-acquired pneumonia administered clarithromycin 500mg immediate-release or amoxicillin/clavulanic acid 875mg/125mg twice daily for 7 days.

MAIN OUTCOME MEASURES AND RESULTS

Similarly high clinical cure rates were observed among evaluable patients in both treatment groups at the test-of-cure visit (28-35 days post-treatment): 92% (114/124) for clarithromycin and 91% (117/129) for amoxicillin/clavulanic acid. Of 85 S. pneumoniae strains isolated pretreatment, four (5%) were classified as resistant to macrolides (one mefA, two ermB, and one ermB + mefA) and eight (9%) had reduced susceptibility to penicillin. The overall eradication rate for pathogens isolated from bacteriologically and clinically evaluable patients was 91% for clarithromycin and 93% for amoxicillin/clavulanic acid, and 89% and 92%, respectively, for S. pneumoniae strains. The rates of resolution and/or improvement in clinical signs and symptoms and radiological improvement were similar with clarithromycin to those with amoxicillin/clavulanic acid, as was overall incidence of adverse events.

CONCLUSION

A 7-day course of clarithromycin immediate-release was similar to amoxicillin/clavulanic acid based on high rates (>90%) of clinical cure, radiological improvement and pathogen eradication among ambulatory-care patients with community-acquired pneumonia. As the resistance rate at baseline was low, no conclusion could be made about clarithromycin's efficacy for infections caused by macrolide-resistant S. pneumoniae. Both treatments were well tolerated.

Antibiotics for community-acquired lower respiratory tract infections secondary to Mycoplasma pneumoniae in children

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is widely recognised as an important cause of community-acquired lower respiratory tract infection (LRTI) in children. Pulmonary manifestations are typically tracheobronchitis or pneumonia but M. pneumoniae is also implicated in wheezing episodes in both asthmatic and non-asthmatic individuals. Although antibiotics are used to treat LRTIs, a review of several major textbooks offers conflicting advice for using antibiotics in the management of M. pneumoniae LRTI in children.

OBJECTIVES

To determine whether antibiotics are effective in the treatment of childhood LRTI secondary to M. pneumoniae infections acquired in the community.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 2), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to February week 5, 2012) and EMBASE (1980 to March 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antibiotics commonly used for treating M. pneumoniae (i.e. macrolide, tetracycline or quinolone classes) versus placebo, or antibiotics from any other class in the treatment of children under 18 years of age with community-acquired LRTI secondary to M. pneumoniae.

DATA COLLECTION AND ANALYSIS

The review authors independently selected trials for inclusion and assessed methodological quality. We extracted and analysed relevant data separately. We resolved disagreements by consensus.

MAIN RESULTS

A total of 1912 children were enrolled from seven studies. Data interpretation was limited by the inability to extract data that referred to children with M. pneumoniae. In most studies, clinical response did not differ between children randomised to a macrolide antibiotic and children randomised to a non-macrolide antibiotic. In one controlled study (of children with recurrent respiratory infections, whose acute LRTI was associated with Mycoplasma, Chlamydia or both by polymerase chain reaction, and/or paired sera) 100% of children treated with azithromycin had clinical resolution of their illness compared to 77% not treated with azithromycin at one month.

AUTHORS' CONCLUSIONS

There is insufficient evidence to draw any specific conclusions about the efficacy of antibiotics for this condition in children (although one trial suggests macrolides may be efficacious in some children with LRTI secondary to Mycoplasma). The use of antibiotics has to be balanced with possible adverse events. There is still a need for high quality, double-blinded RCTs to assess the efficacy and safety of antibiotics for LRTI secondary to M. pneumoniae in children.

Macrolides: A Canadian Infectious Disease Society position paper

Since the introduction of erythromycin in 1965, no new compounds from the macrolide antimicrobial class were licensed in Canada until the 1990s. Clarithromycin and azithromycin, since their introduction, have become important agents for treating a number of common and uncommon infectious diseases. They have become prime agents in the treatment of respiratory tract infections, and have revolutionized the management of both genital chlamydial infections, by the use of single-dose therapy with azithromycin, and nontuberculous mycobacterial infections, by the use of clarithromycin. The improvement of clarithromycin and azithromycin over the gastrointestinal intolerability of erythromycin has led to supplanting the use of the latter for many primary care physicians. Unfortunately, the use of these agents has also increased the likelihood for misuse and has raised concerns about a resultant increase in the rates of macrolide resistance in many important pathogens, such as Streptococcus pneumoniae. This paper reviews the pharmacology and evidence for the current indications for use of these newer agents, and provides recommendations for appropriate use.

Antibiotics for community-acquired lower respiratory tract infections secondary to Mycoplasma pneumoniae in children

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is widely recognised as an important cause of community-acquired lower respiratory tract infection (LRTI) in children. Pulmonary manifestations are typically tracheobronchitis or pneumonia but M. pneumoniae is also implicated in wheezing episodes in both asthmatic and non-asthmatic individuals. Although antibiotics are used to treat LRTI, a review of several major textbooks offers conflicting advice for using antibiotics in the management of M. pneumoniae LRTI in children.

OBJECTIVES

To determine whether antibiotics are effective in the treatment of childhood LRTI secondary to M. pneumoniae infections acquired in the community.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, issue 1), which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to February 2010) and EMBASE (1980 to February 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antibiotics commonly used for treating M. pneumoniae (i.e. macrolide, tetracycline or quinolone classes) versus placebo, or antibiotics from any other class in the treatment of children under 18 years of age with community-acquired LRTI secondary to M. pneumoniae.

DATA COLLECTION AND ANALYSIS

The review authors independently selected trials for inclusion and assessed methodological quality. We extracted and analysed relevant data separately. Disagreements were resolved by consensus.

MAIN RESULTS

A total of 1912 children were enrolled from seven studies. Data interpretation was limited by the inability to extract data that referred to children with M. pneumoniae. In most studies, clinical response did not differ between children randomised to a macrolide antibiotic and children randomised to a non-macrolide antibiotic. In one controlled study (of children with recurrent respiratory infections, whose acute LRTI was associated with Mycoplasma, Chlamydia or both by polymerase chain reaction, and/or paired sera) 100% of children treated with azithromycin had clinical resolution of their illness compared to 77% not treated with azithromycin at one month.

AUTHORS' CONCLUSIONS

There is insufficient evidence to draw any specific conclusions about the efficacy of antibiotics for this condition in children (although one trial suggests macrolides may be efficacious in some children with LRTI secondary to Mycoplasma). The use of antibiotics has to be balanced with possible adverse events. There is still a need for high quality, double-blinded RCTs to assess the efficacy and safety of antibiotics for LRTI secondary to M. pneumoniae in children.

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.

[Routine use of extended-release clarithromycin tablets for short-course treatment of acute exacerbations of non-severe COPD]

OBJECTIVE

This study was designed to confirm, in routine clinical practice conditions, the success rates and safety of extended-release clarithromycin tablets in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD), according to the usual empirical criteria in routine clinical practice.

PATIENTS AND METHODS

An open-label, pharmacoepidemiological, clinical study in community practice was performed with 180 practitioners. The bacterial origin was suspected when sputum was obviously purulent.

RESULTS

Seven hundred and nineteen adult patients with acute exacerbation of mild or moderately severe COPD were included. A favorable clinical course of the exacerbation was observed in 92.5% of cases, with resolution of frankly purulent sputum in 99% of cases, associated with good tolerance.

CONCLUSION

These results confirm the value of extended-release clarithromycin tablets as first-line treatment for presumed bacterial exacerbation of mild or moderately severe, stable COPD according to the Société de pathologie infectieuse de langue française consensus.

Antibiotics for community acquired lower respiratory tract infections (LRTI) secondary to Mycoplasma pneumoniae in children

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is widely recognised as an important cause of community-acquired lower respiratory tract infection (LRTI) in children. Pulmonary manifestations are typically tracheobronchitis or pneumonia but M. pneumoniae is also implicated in wheezing episodes in both asthmatic and non-asthmatic individuals. Although antibiotics are used to treat LRTI, a review of several major textbooks offers conflicting advice for the use of antibiotics in the management of M. pneumoniae LRTI in children.

OBJECTIVES

To determine whether antibiotics are effective in the treatment of childhood LRTI secondary to M. pneumoniae infections acquired in the community.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005), which contains the ARI Group's specialised register of trials; MEDLINE (1966 to February 2005); and EMBASE (1980 to December 2004).

SELECTION CRITERIA

Randomised controlled trials comparing antibiotics commonly used for treating M. pneumoniae (i.e. macrolide, tetracycline or quinolone classes) versus placebo, or antibiotics from any other class in the treatment of children under 18 years of age with community acquired LRTI secondary to M. pneumoniae.

DATA COLLECTION AND ANALYSIS

The authors independently selected trials for inclusion and assessed methodological quality. Relevant data were extracted and analysed separately and any disagreements were resolved by consensus.

MAIN RESULTS

A total of 1352 children were enrolled from six studies. The number of children from one study was unavailable. Data interpretation was significantly limited by the inability to extract data that specifically referred to children with M. pneumoniae. Clinical response did not differ between the children randomised to a macrolide antibiotic and the children randomised to a non-macrolide antibiotic. There were no studies comparing relevant antibiotics with placebo.

AUTHORS' CONCLUSIONS

This review found insufficient evidence to draw any conclusions about the efficacy of antibiotics for LRTI secondary to M. pneumoniae in children. The use of antibiotics for M. pneumoniae LRTI has to be individualised and balanced with possible adverse events associated with antibiotic use. There is a need for high quality, double-blinded randomised controlled trials to assess the efficacy and safety of antibiotics for LRTI secondary to M. pneumoniae in children.

Community-acquired pneumonia: causes of treatment failure in patients enrolled in clinical trials

In order to determine the causes of treatment failure in community-acquired pneumonia (CAP) clinical trials, a MEDLINE search for all CAP studies published between 1990 and 1997 was performed. Prospective, randomized studies comparing the efficacy of two or more antibiotics in CAP were selected. Treatment failure was defined as persistent fever, deterioration of patient's condition, or a change in the prescribed antibiotic regimen. In 16% of the cases included in the clinical trials, the treatment of CAP is unsuccessful. A significant number of identified failure cases were owing to antibiotic side-effects. Resistant pathogens are an unusual cause of failure whatever the antibiotic used.

Antibiotics for community acquired pneumonia in adult outpatients

BACKGROUND

Community-acquired pneumonia (CAP) is a common condition representing a significant disease burden for the community, particularly for the elderly. Because antibiotics are helpful in treating CAP, they are the standard treatment and CAP thus contributes significantly to antibiotic use, which is associated with the development of bacterial resistance and side-effects. Although several studies have been published concerning CAP and its treatment, the available data arises mainly from studies conducted in hospitalized patients and outpatients. There is no concise summary of the available evidence that can help clinicians in choosing the most appropriate antibiotic.

OBJECTIVES

Our goal was to summarize the evidence currently available from randomized controlled trials (RCTs) concerning the efficacy of alternative antibiotic treatments for CAP in ambulatory patients above 12 years of age.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2003) which contains the Cochrane Acute Respiratory Infections Group's trial register; MEDLINE (January 1966 to September week 3, 2003), and EMBASE (January 1974 to March 2003). Studies were also identified by checking the bibliographies of studies and review articles retrieved as well as by perusing medical journals. To identify any additional published or unpublished studies, we contacted the following antibiotics manufacturers: Abbott, AstraZeneca, Aventis, Boehringer-Ingelheim, Bristol-Myers-Squibb, GlaxoSmithKline, Hoffmann-LaRoche, Lilly, Merck, Merck Sharp & Dohme, Novartis, Pfizer, Pharmacia, Sanofi, and Yamanouchi. No language restrictions were applied in any of the search strategies.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) in which one or more antibiotics were tested for the treatment of CAP in ambulatory adolescent or adult patients. Studies testing one or more antibiotic and reporting the diagnostic criteria used in selecting patients as well as the clinical outcomes achieved were included. No language restrictions were applied.

DATA COLLECTION AND ANALYSIS

Data were extracted and study reports assessed by two independent reviewers (LMB and TJMV). Authors of studies were contacted as needed to resolve any ambiguities in the study reports. The data were analyzed using the Cochrane Collaboration's RevMan 4.2.2 Software. Differences between reviewers were resolved by discussion and consensus.

MAIN RESULTS

Three randomized controlled trials involving a total of 622 patients aged 12 years and older diagnosed with community acquired pneumonia were included. The quality of the studies and of the reporting was variable. 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 under study.

REVIEWERS' 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 community acquired pneumonia in ambulatory patients. Pooling of study data was limited by the very low number of studies. 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.

Community-acquired pneumonia in southeast Asia: the microbial differences between ambulatory and hospitalized patients

STUDY OBJECTIVES

To determine microbial agents causing community-acquired pneumonia (CAP) in Southeast Asia.

DESIGN

A prospective study.

SETTING

Three general hospitals in Thailand.

PATIENTS

Two hundred forty-five adult patients fulfilling the clinical criteria of CAP from September 1998 to April 2001.

INTERVENTIONS

Investigations included sputum Gram stain and culture, blood culture, pleural fluid culture (if presented), urine antigen for Legionella pneumophila and Streptococcus pneumoniae, and serology for Mycoplasma pneumoniae, Chlamydia pneumoniae, and L pneumophila.

RESULTS

There were 98 outpatients and 147 hospitalized patients included in the study, and an organism was identified in 74 of 98 outpatients (75.5%) and 105 of 147 of the hospitalized patients (71.4%). C pneumoniae (36.7%), M pneumoniae (29.6%), and S pneumoniae (13.3%) were the most frequent causative pathogens found in outpatients, while S pneumoniae (22.4%) and C pneumoniae (16.3%) were the most common in hospitalized patients. There was a significantly higher incidence of C pneumoniae (36.7% vs 16.3%, respectively; p < 0.001) and M pneumoniae (29.6% vs 6.8%; p < 0.001, respectively) in the outpatients than in the hospitalized patients. The incidence of S pneumoniae, L pneumophila, and mixed infections was not different between the groups. Mixed infections were presented in 13 of 98 outpatients (13.3%) and 9 of 147 hospitalized patients (6.1%), with C pneumoniae being the most frequent coinfecting pathogen.

CONCLUSIONS

The data indicate that the core organisms causing CAP in Southeast Asia are not different from those in the Western countries. The guidelines for the treatment of patients with CAP, therefore, should be the same.

Mycoplasma pneumoniae infections

Mycoplasma pneumoniae is a frequent cause of community-acquired respiratory infections in children and adults. Although the organism is felt to be the most frequent 'atypical' pathogen responsible for community-acquired pneumonia in adults, the prevalence of M. pneumoniae varies greatly from study to study, depending on the population and the diagnostic methods used. Recent studies have found the prevalence of M. pneumoniae in adults with pneumonia to range from 1.9 to over 30%. M. pneumoniae is also a frequent cause of outbreaks of respiratory disease in institutional settings. However, the diagnosis of M. pneumoniae infection is hampered by the lack of standardized, rapid, specific methods. This problem was illustrated by the results of an investigation of an outbreak of M. pneumoniae infection in a federal training facility. Accurate diagnosis required a combination of polymerase chain reaction and serology, as IgM antibodies were not present early in the course of the infection in many patients. Several papers evaluating various serological and polymerase chain reaction assays were published during the period of this review. An assessment of the actual performance of these tests was also hampered by the lack of standardized comparative methods. M. pneumoniae is susceptible in vitro to macrolides, tetracyclines and quinolone antibiotics; however, data are limited on the microbiological efficacy of these agents. Several pneumonia treatment studies were published during this period, practically all of them based the diagnosis of M. pneumoniae infection on serology; different methods and criteria were used in each study, and thus the microbiological efficacy could not be assessed. The Infectious Disease Society of America recently stated in their revised Practice Guidelines for the Management of Community-Acquired Pneumonia in Adults that, as there were no diagnostic tests available that reliably and rapidly detect M. pneumoniae, therapy must usually be empirical.

The newer macrolides: azithromycin and clarithromycin

Azithromycin and clarithromycin are two relatively new macrolide antimicrobial agents. Although azithromycin and clarithromycin are structural analogues of erythromycin, they offer distinct advantages in comparison. This article reviews the pharmacokinetics, antimicrobial activity, clinical use, and adverse affects of these antimicrobial agents.

Cost-effectiveness of sparfloxacin compared with other oral antimicrobials in outpatient treatment of community-acquired pneumonia

We examined the cost-effectiveness of sparfloxacin compared with other selected oral antimicrobials in outpatient treatment of community-acquired pneumonia (CAP) using clinical pathway-based decision analysis. Cost estimates were obtained from medical claims databases and Medicare reimbursement schedules. Probability estimates were derived from published clinical trials, the medical literature, and clinical expert opinion. Overall adjusted efficacy rates were 89% for sparfloxacin, 79.4% for azithromycin, 77.8% for clarithromycin, 73% for cefaclor, 70.8% for amoxicillin-clavulanic acid, and 69% for erythromycin. The expected total cost/CAP episode of treatment with sparfloxacin was $216.07 compared with $258.97, $297.08, $345.75, $389.80, and $395.93 for azithromycin, clarithromycin, erythromycin, amoxicillin-clavulanic acid, and cefaclor, respectively. Therapy with sparfloxacin for managing CAP is cost effective-relative to other commonly prescribed antibiotics, resulting in net cost savings.

Evidence-based medicine: empiric antibiotic therapy in community-acquired pneumonia

A number of national society guidelines exist for empiric management of community-acquired pneumonia but these are, to a large extent, not evidence-based, but based on clinical experience, in vitro data, pragmatism and common sense. Many randomized controlled trials of antibiotic therapy in community-acquired pneumonia have been conducted, but most of these have been powered to demonstrate equivalent efficacy of new treatments in comparison with conventional antimicrobial therapy. Development of new antibiotics has been driven by the emergence of penicillin-resistant Streptococcus pneumoniae, but so far there is no hard evidence that beta-lactam therapy fails in community-acquired pneumonia, at least with the higher doses of penicillins that are commonly used in hospital practice. Nonetheless, newer antibiotics have been deployed including macrolides and quinolones, and have demonstrated equivalent (and in some cases, marginally improved) efficacy to older antibiotic treatments in randomized control trials. A number of studies have shown that it is possible to stratify patients according to severity of illness, to in-patient or out-patient management protocols. These have been validated and refined.

The macrolides: erythromycin, clarithromycin, and azithromycin

In addition to erythromycin, macrolides now available in the United States include azithromycin and clarithromycin. These two new macrolides are more chemically stable and better tolerated than erythromycin, and they have a broader antimicrobial spectrum than erythromycin against Mycobacterium avium complex (MAC), Haemophilus influenzae, nontuberculous mycobacteria, and Chlamydia trachomatis. All three macrolides have excellent activity against the atypical respiratory pathogens (C. pneumoniae and Mycoplasma species) and the Legionella species. Azithromycin and clarithromycin have pharmacokinetics that allow shorter dosing schedules because of prolonged tissue levels. Both azithromycin and clarithromycin are active agents for MAC prophylaxis in patients with late-stage acquired immunodeficiency syndrome (AIDS), although azithromycin may be the preferable agent because of fewer drug-drug interactions. Clarithromycin is the most active MAC antimicrobial agent and should be part of any drug regimen for treating active MAC disease in patients with or without AIDS. Although both azithromycin and clarithromycin are well tolerated by children, azithromycin has the advantage of shorter treatment regimens and improved tolerance, potentially improving compliance in the treatment of respiratory tract and skin or soft tissue infections. Intravenously administered azithromycin has been approved for treatment of adults with mild to moderate community-acquired pneumonia or pelvic inflammatory diseases. An area of concern is the increasing macrolide resistance that is being reported with some of the common pathogens, particularly Streptococcus pneumoniae, group A streptococci, and H. influenzae. The emergence of macrolide resistance with these common pathogens may limit the clinical usefulness of this class of antimicrobial agents in the future.

Review and comparison of advanced-generation macrolides clarithromycin and dirithromycin

We reviewed English-language clinical studies, abstracts, and review articles identified from MEDLINE searches from January 1966-August 1998, and bibliographies of identified articles to compare advanced-generation macrolides dirithromycin and clarithromycin and their use for respiratory tract infections. Both agents have superior adverse effect profiles compared with erythromycin, the original macrolide. Both have broad antibacterial coverage, but clarithromycin usually has a lower MIC90 to susceptible organisms than dirithromycin; for most isolates this difference is not clinically significant. Clarithromycin has better in vitro coverage of Haemophilus influenzae, but this activity varies with formation of its bioactive metabolite, 14-hydroxyclarithromycin. Neither agent is ideal for H. influenzae eradication. The agents differ markedly in terms of pharmacokinetics, pharmacodynamics, metabolism, and cost, and thus with respect to drug interaction profiles and dosages. Dirithromycin's drug interaction profile is markedly better than clarithromycin's. Clarithromycin is dosed twice/day; dirithromycin's pharmacokinetics allow once/day dosing. Dirithromycin is less expensive with regard to both cost/day and cost/treatment regimen. Clarithromycin has been studied and approved for administration to children. In adults with respiratory tract infections who are receiving drugs that would interact with clarithromycin, and in those with renal dysfunction with or without coexisting hepatic dysfunction, dirithromycin appears to be superior in terms of safety and equivalent to clarithromycin in terms of efficacy.

Community-acquired pneumonia

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in all age groups, especially the elderly, which is a patient population that continues to grow. Recently the spectrum and clinical picture of pneumonia has been changing as a reflection of this aging population; this requires a reassessment of and a new approach to the patient with pneumonia. Currently, pneumonia patients are classified as having either community-acquired or hospital-acquired infection rather than typical versus atypical. Patients who have CAP are categorized by age, presence of a coexisting medical illness, and the severity of the pneumonia. The rationale behind categorizing patients is to stratify them in terms of mortality risk to help determine the location of therapy (e.g., outpatient, inpatient, intensive care unit) and focus the choice of initial antimicrobial therapy. Once the decision to hospitalize a patient with pneumonia is made, the next step is to decide on an appropriate diagnostic evaluation and antibiotic therapy. Both decisions have evolved over the last several years since the publication of the American Thoracic Society's CAP guidelines. The current approach to the diagnostic work-up of pneumonia stresses a limited role of diagnostic tests and procedures. The antimicrobial regimen has now evolved into one that is empiric in nature and based on the age of the patient, the presence of coexisting medical disease, and the overall severity of the pneumonia. This process is a dynamic once because bacterial resistance to commonly used antibiotics can further complicate the course of pneumonia therapy, but the impact of resistance on outcome is less clear. Resistance of Streptococcus pneumoniae to penicillin is a prime example of this growing problem, and adjustment to pneumonia therapy may be required. A difficult but not uncommon problem in pneumonia patients is slow recovery and delayed resolution of radiographic infiltrates. Factors that impact negatively on pneumonia resolution include advanced age and the presence of serious comorbid illnesses such as diabetes mellitus, renal disease, or chronic obstructive pulmonary disease. In addition, certain organism factors (e.g., intrinsic virulence) may interact with host factors and advanced age to delay pneumonia resolution. For example, 50% of patients with pneumococcal pneumonia have radiographic clearing at 5 weeks, and the majority clear within 2 to 3 months. Recent data demonstrate that radiographic resolution of CAP is most influenced by the number of lobes involved and the age of the patient. Radiographic clearance of CAP decreases by 20% per decade after age 20, and patients with multilobar infiltrates take longer to clear than those with unilobar disease. In general, when approaching slowly resolving infiltrates after pneumonia, bronchoscopic evaluation and lung biopsy are more likely to yield a specific diagnosis if the patient is a nonsmoker younger than 55 years old with multilobar disease. If the patients has either no identifiable factors associated with prolonged pneumonia resolution or the repeat chest radiograph at 1 month shows no appreciable change, further diagnostic testing is indicated. The route and duration of antibiotic therapy, another detail of the management of CAP patients that has changed recently, is complicated by the fact that the majority of patients with CAP have no pathogen identified. Therefore, in most instances the physician initiates empiric antibiotics on the basis of epidemiologic data. If an etiologic pathogen is identified (either initially or at a later time), then the antibiotic spectrum can be narrowed. When no pathogen is discovered, broad-spectrum empiric antibiotics are continued. (ABSTRACT TRUNCATED)

Comparison of cefdinir and cefaclor in treatment of community-acquired pneumonia

Six hundred ninety patients were enrolled in a multicenter, randomized, double-blind trial comparing the efficacy and safety of cefdinir with those of cefaclor in the treatment of community-acquired pneumonia. Patients received either 10 days of treatment with cefdinir (n = 347) at 300 mg twice daily or 10 days of treatment with cefaclor (n = 343) at 500 mg three times daily. Microbiological assessments were performed on sputum specimens obtained at admission and at the two posttherapy visits, if available. Respiratory tract pathogens were isolated from 538 (78%) of 690 patient admission sputum specimens, with the predominant pathogens being Haemophilus parainfluenzae, Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus. The microbiological eradication rates at the test-of-cure visit were 92% (238 of 260 pathogens) and 93% (245 of 264 pathogens) for the evaluable patients treated with cefdinir and cefaclor, respectively. A satisfactory clinical response (cure plus improvement) was achieved in 89% (166 of 187) and 86% (160 of 186) of the evaluable patients treated with cefdinir and cefaclor, respectively. Except for the incidence of diarrhea, adverse event rates while on treatment were equivalent between the two treatment groups. Diarrhea incidence during therapy was higher for patients treated with cefdinir (13.7%) than for patients treated with cefaclor (5.3%). These results indicate that cefdinir is effective and safe in the treatment of patients with pneumonia.

Clarithromycin. A review of its efficacy in the treatment of respiratory tract infections in immunocompetent patients

Clarithromycin is a broad spectrum macrolide antibacterial agent active in vitro and effective in vivo against the major pathogens responsible for respiratory tract infections in immunocompetent patients. It is highly active in vitro against pathogens causing atypical pneumonia (Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp.) and has similar activity to other macrolides against Staphylococcus aureus. Streptococcus pyogenes, Moraxella catarrhalis and Streptococcus pneumoniae. Haemophilus influenzae is susceptible or intermediately susceptible to clarithromycin alone, but activity is enhanced when the parent drug and metabolite are combined in vitro. Absorption of clarithromycin is unaffected by food. More than half of an oral dose is systemically available as the parent drug and the active 14-hydroxy metabolite. Pharmacokinetics are nonlinear, with plasma concentrations increasing in more than proportion to the dosage. First-pass metabolism results in the rapid appearance of the active metabolite 14-hydroxy-clarithromycin in plasma. Clarithromycin and its active metabolite are found in greater concentrations in the tissues and fluids of the respiratory tract than in plasma. Dosage adjustments are required for patients with severe renal failure, but not for elderly patients or those with hepatic impairment. Drug interactions related to the cytochrome P450 system may occur with clarithromycin use. In addition to the standard immediate-release formulation for administration twice daily, a modified-release formulation of clarithromycin is now available for use once daily. In dosages of 500 to 1000 mg/day for 5 to 14 days, clarithromycin was as effective in the treatment of community-acquired upper and lower respiratory tract infections in hospital and community settings as beta-lactam agents (with or without a beta-lactamase inhibitor), cephalosporins and most other macrolides. Clarithromycin was similar in efficacy to azithromycin in comparative studies and is as effective as and better tolerated than erythromycin. Adverse events are primarily gastrointestinal in nature, but result in fewer withdrawals from therapy than are seen with erythromycin. Clarithromycin provides similar clinical and bacteriological efficacy to that seen with beta-lactam agents, cephalosporins and other macrolides. It offers a cost-saving alternative to intravenous erythromycin use in US hospitals and is available in both once-daily and twice-daily formulations. The spectrum of activity of clarithromycin against common and emerging respiratory tract pathogens may make it suitable for use in the community as empirical therapy of respiratory tract infections in both children and adults.

Azithromycin and clarithromycin

Azithromycin and clarithromycin are alternatives to conventional macrolides in the routine treatment of many dermatologic, upper respiratory, and lower respiratory tract infections. In this role as alternative therapy, they are better tolerated, less toxic, and more convenient to take, although at a greater cost to the patient. This dosing convenience is an important consideration for the clinician; as shown by Nelson, patient compliance ranges from 95% with once-daily dosing to 58% with four-times-a-day dosing. Thus, less frequent dosing with both drugs as well as the shorter course of therapy possible with azithromycin may be therapeutically advantageous. In addition to their role as alternatives to conventional macrolide therapy, azithromycin and clarithromycin extend the spectrum of macrolides and offer new therapeutic options for H. influenzae, MAC in AIDS, MOTT, and leprosy. Finally, experimental therapy may extend their use for additional opportunistic infections, such as toxoplasmosis and cryptosporidiosis.

Clarithromycin clinical pharmacokinetics

Clarithromycin is a semisynthetic macrolide antibiotic, structurally related to erythromycin. It has a more favourable pharmacokinetic profile than erythromycin, thus allowing twice-daily administration and possibly increasing compliance among outpatients. Clarithromycin is well absorbed from the gastrointestinal tract and its systemic bioavailability (about 55%) is reduced because of first-pass metabolism. It undergoes rapid biodegradation to produce the microbiologically active 14-hydroxy-(R)-metabolite. The maximum serum concentrations of clarithromycin and its 14-hydroxy metabolite, following single oral doses, are dose proportional and appear within 3 hours. With multiple doses, steady-state concentrations are attained after 5 doses and the maximal serum concentrations of clarithromycin and of the 14-hydroxy derivative appear within 2 hours after the last dose. Clarithromycin is well distributed throughout the body and achieves higher concentrations in tissues than in the blood. Also, the 14-hydroxy metabolite exhibits high tissue concentrations, with values about one-third of the parent compound concentrations. The presence of food appears to have no clinically significant effect on clarithromycin pharmacokinetics. The main metabolic pathways are oxidative N-demethylation and hydroxylation, which are saturable and result in nonlinear pharmacokinetics. The primary metabolite (14-hydroxy derivative) is mainly excreted in the urine with the parent compound. A reduction in urinary clearance in the elderly and in patients with renal impairment is associated with an increase in area under the plasma concentration-time curve, peak plasma concentrations and elimination half-life. Mild hepatic impairment does not significantly modify clarithromycin pharmacokinetics. In conclusion, clarithromycin, because of its antibacterial activity and pharmacokinetic properties, appears to be a useful alternative to other macrolides in the treatment of community acquired infections.