Effectiveness of levofloxacin for adult community-acquired pneumonia caused by macrolide-resistant Streptococcus pneumoniae: integrated results from four open-label, multicenter, phase III clinical trials

Short-course versus long-course therapy of the same antibiotic for community-acquired pneumonia in adolescent and adult outpatients

BACKGROUND

Community-acquired pneumonia (CAP) is a lung infection that can be acquired during day-to-day activities in the community (not while receiving care in a hospital). Community-acquired pneumonia poses a significant public health burden in terms of mortality, morbidity, and costs. Shorter antibiotic courses for CAP may limit treatment costs and adverse effects, but the optimal duration of antibiotic treatment is uncertain.

OBJECTIVES

To evaluate the efficacy and safety of short-course versus longer-course treatment with the same antibiotic at the same daily dosage for CAP in non-hospitalised adolescents and adults (outpatients). We planned to investigate non-inferiority of short-course versus longer-term course treatment for efficacy outcomes, and superiority of short-course treatment for safety outcomes.

SEARCH METHODS

We searched CENTRAL, which contains the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE, Embase, five other databases, and three trials registers on 28 September 2017 together with conference proceedings, reference checking, and contact with experts and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short- and long-courses of the same antibiotic for CAP in adolescent and adult outpatients.

DATA COLLECTION AND ANALYSIS

We planned to use standard Cochrane methods.

MAIN RESULTS

Our searches identified 5260 records. We did not identify any RCTs that compared short- and longer-courses of the same antibiotic for the treatment of adolescents and adult outpatients with CAP.We excluded two RCTs that compared short courses (five compared to seven days) of the same antibiotic at the same daily dose because they evaluated antibiotics (gemifloxacin and telithromycin) not commonly used in practice for the treatment of CAP. In particular, gemifloxacin is no longer approved for the treatment of mild-to-moderate CAP due to its questionable risk-benefit balance, and reported adverse effects. Moreover, the safety profile of telithromycin is also cause for concern.We found one ongoing study that we will assess for inclusion in future updates of the review.

AUTHORS' CONCLUSIONS

We found no eligible RCTs that studied a short-course of antibiotic compared to a longer-course (with the same antibiotic at the same daily dosage) for CAP in adolescent and adult outpatients. The effects of antibiotic therapy duration for CAP in adolescent and adult outpatients remains unclear.

Efficacy and safety of levofloxacin in the context of other contemporary fluoroquinolones: a review

BACKGROUND

In recent years, fluoroquinolone research has focused on achieving several goals, including (1) enhanced potency against gram-positive cocci, notably Streptococcus pneumoniae, and anaerobes, while (2) maintaining potency against gram-negative pathogens, (3) optimizing pharmacokinetics and pharmacodynamics (PK/PD), and (4) minimizing potential adverse drug reactions through recognition and avoidance of structural configurations that have characterized earlier, reactive compounds.

OBJECTIVE

This review examines the efficacy and safety of fluoroquinolones and the specific clinical evidence regarding levofloxacin.

METHODS

Using published literature collected over time by the author, a review was conducted, focusing on the efficacy and safety profile of levofloxacin and other fluoroquinolones.

RESULTS

The newer fluoroquinolones have fulfilled many of the research goals described above. Levofloxacin has improved anti-gram-positive potency, PK/PD properties, a proven clinical trial record (particularly for communityacquired pneumonia [CAP]), and an excellent safety profile-in the context of the treatment of >250 million patients worldwide in the past decade. It is licensed for management of drug-resistant S pneumoniae infections in the United States and has gained widespread formulary acceptance and guideline inclusion. Studies assessing levofloxacin for CAP therapy show significant advantages over standard therapy, such as trends toward reduced IV therapy and length of hospitalization, reduced mortality, and significant associated cost reduction. In addition, levofloxacin has proved highly effective in acute exacerbations of chronic bronchitis (AECB), with excellent clinical and bacteriologic results, typical of the class, and significant advantages-in terms of clinical response, overall pathogen eradication, extension of the symptom-free period, and trends toward a reduction in the number of consultation visits and hospitalizations-over standard agents, such as the oral cephalosporins.

CONCLUSIONS

Levofloxacin offers a combination of documented efficacy and tolerability, and provides an important option for the treatment of bacterial infections, including CAP and AECB, compared with standard agents used in the management of lower respiratory tract infections.

Use of the respiratory fluoroquinolones for the outpatient management of community-acquired pneumonia

BACKGROUND

Approximately 4 million cases of community-acquired pneumonia (CAP) occur in the United States each year, with the majority treated on an outpatient basis. The first fluoroquinolones (eg, ciprofloxacin) were used with caution for respiratory tract infections due to limited in vitro activity against common gram-positive pathogens. With the availability of levofloxacin, followed by gatifloxacin and moxifloxacin hydrochloride, which exhibited increased activity against gram-positive organisms, the fluoroquinolones have become a practical choice for the treatment of CAP.

OBJECTIVE

The aim of this review was to compare the respiratory fluoroquinolones in the outpatient management of CAP.

METHODS

We conducted a search for English-language articles (key terms: fluoroquinolone, levofloxacin, gatifloxacin, moxifloxacin, and pneumonia; years: 1996-2004). Data from published literature were reviewed regarding clinical and microbiologic efficacy and tolerability; pharmacokinetic and pharmacodynamic properties; and drug costs of levofloxacin, gatifloxacin, and moxifloxacin.

RESULTS

The 3 fluoroquinolones reviewed showed comparable clinical and microbiologic efficacy for the treatment of CAP. In general, the fluoroquinolones were well tolerated, although some differences have been reported, including higher rates of gastrointestinal and other adverse events for gatifloxacin and moxifloxacin. Gatifloxacin and moxifloxacin exhibited greater in vitro potency than levofloxacin against Streptococcus pneumoniae. However, levofloxacin achieved a higher serum drug concentration than the other agents, allowing similar attainment of pharmacokinetic and pharmacodynamic targets required for effective treatment.

CONCLUSIONS

The respiratory fluoroquinolones provided appropriate first line treatment in select patients with CAP on the basis of their microbiologic and clinical efficacy and their safety profiles.

Fluoroquinolones in the management of community-acquired pneumonia in primary care

A literature search was conducted to evaluate the pharmacokinetic and pharmacodynamic profile of the respiratory fluoroquinolones (gemifloxacin, levofloxacin and moxifloxacin) and their efficacy and safety in the management of community-acquired pneumonia (CAP). Data show that CAP is a common presentation in primary care practice, and is associated with high rates of morbidity and mortality, particularly in the elderly. Although the causative pathogens differ depending on treatment setting and patient factors, Streptococcus pneumoniae is the primary pathogen in all treatment settings. As a class, the respiratory fluoroquinolones have a very favorable pharmacokinetic and pharmacodynamic profile. Pharmacodynamic criteria suggest that moxifloxacin and gemifloxacin are more potent against S. pneumoniae, which may have the added benefit of reducing resistance selection and enhancing bacterial eradication. The respiratory fluoroquinolones are also generally well tolerated, and are first-line options for outpatient treatment of CAP in patients with comorbidities or previous antibiotic use.

Diversity and susceptibility of Enterococcus isolated from cattle before and after harvest

To investigate evidence of cross-contamination and to determine patterns of antimicrobial drug susceptibility of Enterococcus isolates in a commercial cattle processing system, samples were collected from 60 cattle shipped to a commercial abattoir. Enterococcus isolates were recovered from fecal and hide samples collected immediately before shipment from a feedlot to the abattoir, from postexsanguination hide samples at the abattoir, and from carcass samples collected after hide removal (preevisceration) and in the cooler. Of the fecal samples, 53.9% were culture positive for Enterococcus. Of hide samples collected at the feedlot, 77.8% were positive for Enterococcus, significantly lower (P < 0.01) than the proportion of hides that were culture positive at the abattoir (96.1%). For preevisceration carcass samples, Enterococcus was recovered from 58.3% of carcasses. Only 8.3% of the carcasses sampled in the cooler yielded Enterococcus. Resistance among Enterococcus isolates was common regardless of the type or location of sample from which the isolate was recovered. All 279 Enterococcus isolates were resistant to at least one antimicrobial drug, and 179 (64.2%) of these isolates were resistant to at least six drugs. The most common resistance was to chloramphenicol (100% of isolates) followed by flavomycin (90.3%), lincomycin (87.8%), tylosin (78.5%), erythromycin (76.3%), tetracycline (58.9%), quinupristin-dalfopristin (47.7%), bacitracin (17.9), streptomycin (9.0%), ciprofloxacin (1.4%), linezolid (0.7%), and salinomycin (0.4%). Enterococcus isolates also were characterized using pulsed-field gel electrophoresis to evaluate molecular similarities. Similar or indistinguishable electrophoresis patterns were found among isolates recovered at the feedlot and in the plant, providing evidence that feedlot-origin bacterial isolates are being transferred from cattle to carcasses within the processing environment through cross-contamination.

Antibacterial activity of telithromycin and comparators against pathogens isolated from patients with community-acquired respiratory tract infections: the Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin study year 5 (2003-2004)

The activity of telithromycin and comparator antibacterials was examined in isolates of Streptococcus pneumoniae and Haemophilus influenzae isolated from patients with community-acquired pneumonia (CAP), acute exacerbations of chronic bronchitis (AECB), or sinusitis during year 5 (2003-2004) of the Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin global resistance surveillance study. Among S. pneumoniae, penicillin nonsusceptibility and erythromycin resistance were 35.7% and 36.0%, respectively. beta-Lactamase was produced by 12.3% of H. influenzae isolates. beta-Lactamase-negative ampicillin-resistant strains, mainly from Japan, comprised 5.2% of global H. influenzae isolates. Telithromycin and levofloxacin were the most active agents tested against S. pneumoniae and H. influenzae (>99% of isolates susceptible) isolated from patients with CAP, AECB, or bacterial sinusitis. Amoxicillin-clavulanate, levofloxacin, and telithromycin were the most active agents against multidrug-resistant S. pneumoniae.

Review: Novel targets in the management of pneumonia

Community-acquired pneumonia (CAP) is the leading cause of death from infectious diseases in the US. It accounts each year for 500,000 hospitalizations and 45,000 deaths and represents one of the most common causes of intensive care unit (ICU) admission. The mortality rate due to severe CAP has shown little improvement in the past three decades, remaining between 21% and 58% in patients admitted to the intensive care unit. Antimicrobial agents are the cornerstone of therapy against CAP, but there are some novel antibiotic and nonantibiotic therapies that have been recently tested that may potentially impact outcomes of patients with severe CAP. We will review the most recent data regarding novel therapies in patients with the highest risk of death such as those with severe CAP.

Community-Acquired Respiratory Complications in the Intensive Care Unit: Pneumonia and Acute Exacerbations of COPD

This chapter will review the two most common lower respiratory tract infections in the intensive care unit (ICU), community-acquired pneumonia (CAP) and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In addition we will provide an overview of the topics including recommendations for the diagnosis and treatment.

The role of new therapies for severe community-acquired pneumonia

PURPOSE OF REVIEW

Community-acquired pneumonia (CAP) is associated with significant morbidity and mortality and is the most common cause of death from infectious diseases. CAP patients requiring intensive care unit (ICU) admission carry the highest mortality rates. This paper aims to review the current literature regarding epidemiology, risk factors, severity criteria and reasons for admitting the hospitalized patient to the ICU, and the empiric and specific antibiotic therapeutic regimens employed.

RECENT FINDINGS

Multiple sets of clinical practice guidelines have been published in the past few years addressing the treatment of CAP. The guidelines all agree that CAP patients admitted to the hospital represent a major concern, and appropriate empiric therapy should be instituted to improve clinical outcomes.

SUMMARY

The cost, morbidity and mortality of CAP patients requiring ICU admission remain unacceptably high. These are heterogeneous groups of patients, so it is important to use risk-stratification based on clinical parameters and prediction tools. Appropriate antibiotic therapy is an important component in the management of both groups of patients. In particular, it is essential to administer an appropriate antimicrobial agent from the initiation of therapy, so that the risks of treatment failure and the morbidity of CAP may be minimized.

Guide to selection of fluoroquinolones in patients with lower respiratory tract infections

Newer fluoroquinolones such as levofloxacin, moxifloxacin, gatifloxacin and gemifloxacin have several attributes that make them excellent choices for the therapy of lower respiratory tract infections. In particular, they have excellent intrinsic activity against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and the atypical respiratory pathogens. Fluoroquinolones may be used as monotherapy to treat high-risk patients with acute exacerbation of chronic bronchitis, and for patients with community-acquired pneumonia requiring hospitalisation, but not admission to intensive care. Overall, the newer fluoroquinolones often achieve clinical cure rates in > or =90% of these patients. However, rates may be lower in hospital-acquired pneumonia, and this infection should be treated on the basis of anticipated organisms and evaluation of risk factors for specific pathogens such as Pseudomonas aeruginosa. In this setting, an antipseudomonal fluoroquinolone may be used in combination with an antipseudomonalbeta-lactam. Concerns are now being raised about the widespread use, and possibly misuse, of fluoroquinolones and the emergence of resistance among S. pneumoniae, Enterobacteriaceae and P. aeruginosa. A number of pharmacokinetic parameters such as the peak concentration of the antibacterial after a dose (C(max)), and the 24-hour area under the concentration-time curve (AUC24) and their relationship to pharmacodynamic parameters such as the minimum inhibitory and the mutant prevention concentrations (MIC and MPC, respectively) have been proposed to predict the effect of fluoroquinolones on bacterial killing and the emergence of resistance. Higher C(max)/MIC or AUC24/MIC and C(max)/MPC or AUC24/MPC ratios, either as a result of dose administration or the susceptibility of the organism, may lead to a better clinical outcome and decrease the emergence of resistance, respectively. Pharmacokinetic profiles that are optimised to target low-level resistant minor subpopulations of bacteria that often exist in infections may help preserve fluoroquinolones as a class. To this end, optimising the AUC24/MPC or C(max)/MPC ratios is important, particularly against S. pneumoniae, in the setting of lower respiratory tract infections. Agents such as moxifloxacin and gemifloxacin with high ratios against this organism are preferred, and agents such as ciprofloxacin with low ratios should be avoided. For agents such as levofloxacin and gatifloxacin, with intermediate ratios against S. pneumoniae, it may be worthwhile considering alternative dose administration strategies, such as using higher dosages, to eradicate low-level resistant variants. This must, of course, be balanced against the potential of toxicity. Innovative approaches to the use of fluoroquinolones are worth testing in further in vitro experiments as well as in clinical trials.

Antimicrobial treatment of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a clinical diagnosis that has a significant impact on health care management around the world. Early clinical suspicion and prompt empiric antimicrobial therapies are mandatory in patients with CAP. This article provides a review of recent studies and guidelines addressing antimicrobial therapy for hospitalized patients with CAP.

[Guidelines for the management of community pneumonia in adult who needs hospitalization]

Community acquired pneumonia is still an important health problem. In Spain the year incidence is 162 cases per 100,000 inhabitants with 53,000 hospital admission costing 115 millions of euros per year. In the last years there have been significant advances in the knowledge of: aetiology, diagnostic tools, treatment alternatives and antibiotic resistance. The Spanish Societies of Intensive and Critical Care (SEMICYUC), Infectious Diseases and Clinical Microbiology (SEIMC) and Pulmonology and Thoracic Surgery (SEPAR) have produced these evidence-based Guidelines for the management of community acquired pneumonia in Adults. The main objective is to help physicians to make decisions about this disease. The different points that have been developed are: aetiology, diagnosis, treatment and prevention.

Nonresponses and treatment failures with conventional empiric regimens in patients with community-acquired pneumonia

Although most patients with suspected CAP respond to empiric therapy,a small number of patients do not respond in the expected fashion. Age and underlying comorbid conditions have a strong influence on the course of illness. Less common causes of treatment failures include overwhelming infection, antimicrobial resistance, and misdiagnosis. It is a common practice for empiric antimicrobial treatment of CAP to be initiated without microbiologic studies. Clinicians carefully should observe these patients for unusual or slow responses and should be ready to pursue a more extensive search for the cause of treatment failure.

Levofloxacin versus ceftriaxone plus clarithromycin in the treatment of adults with community-acquired pneumonia requiring hospitalization

Consecutive adult patients admitted to the hospital with community-acquired pneumonia from January 2000 to September 2003 were included in this prospective observational cohort study. A total of 459 patients, 259 treated with levofloxacin in single drug therapy at a dose of 500 mg once a day and 209 with the combination of ceftriaxone plus clarithromycin at a dose of 2 g once a day and 500 mg every 12 h, respectively, were included. The hospital admission decision was made using a clinical guideline based on the Pneumonia Severity Index (PSI). Fifteen (6%) patients died in the group treated with levofloxacin in single drug therapy and 25 (12%) in the group treated with ceftriaxone plus clarithromycin (P = 0.024). The mortality differences between both treatment groups, adjusted by the PSI score, show an OR of 0.39 (95% CI 0.17-0.87). There were no statistically significant differences between the duration of treatments or hospital stay. These data suggest that levofloxacin as single drug therapy is more effective than the combination of ceftriaxone plus clarithromycin in the treatment of moderate to severe pneumonia that requires hospitalization.

Levofloxacin: a review of its use in the treatment of bacterial infections in the United States

Levofloxacin (Levaquin) is a fluoroquinolone antibacterial agent with a broad spectrum of activity against Gram-positive and Gram-negative bacteria and atypical respiratory pathogens. It is active against both penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae. The prevalence of S. pneumoniae resistance to levofloxacin is <1% overall in the US.A number of randomised comparative trials in the US have demonstrated the efficacy of levofloxacin in the treatment of infections of the respiratory tract, genitourinary tract, skin and skin structures. Sequential intravenous to oral levofloxacin 750mg once daily for 7-14 days was as effective in the treatment of nosocomial pneumonia as intravenous imipenem/cilastatin 500-1000mg every 6-8 hours followed by oral ciprofloxacin 750mg twice daily in one study. In patients with mild to severe community-acquired pneumonia (CAP), intravenous and/or oral levofloxacin 500mg once daily for 7-14 days achieved clinical and bacteriological response rates similar to those with comparator agents, including amoxicillin/clavulanic acid, clarithromycin, azithromycin, ceftriaxone and/or cefuroxime axetil and gatifloxacin. A recent study indicates that intravenous or oral levofloxacin 750mg once daily for 5 days is as effective as 500mg once daily for 10 days, in the treatment of mild to severe CAP. Exacerbations of chronic bronchitis and acute maxillary sinusitis respond well to treatment with oral levofloxacin 500mg once daily for 7 and 10-14 days, respectively. Oral levofloxacin was as effective as ofloxacin in uncomplicated urinary tract infections and ciprofloxacin or lomefloxacin in complicated urinary tract infections. In men with chronic bacterial prostatitis treated for 28 days, oral levofloxacin 500mg once daily achieved similar clinical and bacteriological response rates to oral ciprofloxacin 500mg twice daily. Uncomplicated skin infections responded well to oral levofloxacin 500mg once daily for 7-10 days, while in complicated skin infections intravenous and/or oral levofloxacin 750mg for 7-14 days was at least as effective as intravenous ticarcillin/clavulanic acid (+/- switch to oral amoxicillin/clavulanic acid) administered for the same duration. Levofloxacin is generally well tolerated, with the most frequently reported adverse events being nausea and diarrhoea; in comparison with some other quinolones it has a low photosensitising potential and clinically significant cardiac and hepatic adverse events are rare.

CONCLUSION

Levofloxacin is a broad-spectrum antibacterial agent with activity against a range of Gram-positive and Gram-negative bacteria and atypical organisms. It provides clinical and bacteriological efficacy in a range of infections, including those caused by both penicillin-susceptible and -resistant strains of S. pneumoniae. Levofloxacin is well tolerated, and is associated with few of the phototoxic, cardiac or hepatic adverse events seen with some other quinolones. It also has a pharmacokinetic profile that is compatible with once-daily administration and allows for sequential intravenous to oral therapy. The recent approvals in the US for use in the treatment of nosocomial pneumonia and chronic bacterial prostatitis, and the introduction of a short-course, high-dose regimen for use in CAP, further extend the role of levofloxacin in treating bacterial infections.

Outcome of treatment of respiratory tract infections due to Streptococcus pneumoniae, including drug-resistant strains, with pharmacokinetically enhanced amoxycillin/clavulanate

The efficacy of a new pharmacokinetically enhanced formulation of amoxycillin/clavulanate (AMX/CA) 2000/125 mg, twice daily, designed to provide adequate levels of amoxycillin over the 12-h dosing interval to eradicate penicillin-resistant Streptococcus pneumoniae (PRSP) with amoxycillin (+/-clavulanic acid) MICs of </=4 mg/l, was evaluated in patients with respiratory infections caused by S. pneumoniae, including PRSP (penicillin MICs 2-16 mg/l). Data from nine clinical studies were combined (total intent-to-treat N=5531). Six randomized, double-blind studies used levofloxacin 500 mg od in acute bacterial sinusitis (ABS), levofloxacin 500 mg od in acute exacerbations of chronic bronchitis (AECB), clarithromycin 500 mg bid in AECB, AMX/CA 875/125 mg bid and tid in community-acquired pneumonia (CAP) and AMX/CA 1000/125 mg tid in CAP as comparators. The three remaining studies (two in ABS and one in CAP) were non-comparative. In the AMX/CA 2000/125 mg bid-treated patients evaluable at follow-up (Day 14-39), outcome was successful in 60/64 (93.7%) patients with S. pneumoniae infections in the comparative studies and 348/363 (95.9%) in the non-comparative studies, including 95.6% of all patients and 95.2% of patients whose isolates had AMX/CA MICs of >/=4 mg/l. In the pooled comparator group, the success rate at follow-up was 86.5% (45/52). For PRSP (AMX/CA MICs of 0.5-8 mg/l), the overall success rate was 98.2% (55/56) at follow-up for AMX/CA 2000/125 mg and 50.0% (2/4) for comparators. AMX/CA 2000/125 mg shows efficacy comparable to that of the comparators evaluated against S. pneumoniae infections. Due to its favorable pharmacokinetic/pharmacodynamic profile and promising clinical success, the new AMX/CA 2000/125 mg formulation should be considered for the empirical treatment of respiratory tract infections in regions with a high prevalence of antimicrobial-resistant S. pneumoniae and in patients at high risk of antimicrobial-resistant S. pneumoniae infection as this formulation covers many PRSP that are non-susceptible to amoxycillin (+/-clavulanic acid) (MICs of >/=4 mg/l) as well as common beta-lactamase-producing respiratory pathogens.

Evaluation and cost assessment of fluoroquinolones in community-acquired respiratory infections

Several new fluoroquinolones have been marketed since the late 1990s. Fluoroquinolones are an effective treatment for most community-acquired respiratory tract infections, including acute sinusitis, acute exacerbations of chronic bronchitis and community-acquired pneumonia. However, other antibiotics, including beta-lactams, macrolides, tetracyclines and trimethoprim-sulfamethoxazole, are also effective against these respiratory infections. From a managed care perspective, it is the subtle differences between the drugs in the eradication of bacterial pathogens, adverse effects, dose regimens, compliance issues, bacterial resistance and cost that determine the best choice for the management of pneumonia, sinusitis or exacerbations of chronic bronchitis. The potential for bacterial resistance is perhaps the only significant barrier to extensive fluoroquinolone use in community-acquired respiratory tract infections. Cost-effectiveness must be balanced with quality care, both from an individual perspective and that of the greater society.

Severe community-acquired pneumonia: current outcomes, epidemiology, etiology, and therapy

Severe community-acquired pneumonia is a clinical diagnosis with a significant impact on healthcare management around the world, with the highest morbidity and mortality of all of the forms of community-acquired pneumonia. Patients with severe pneumonia usually require intensive care unit management, including vasopressors or mechanical ventilation. Early clinical suspicion and prompt empiric antimicrobial therapies are mandatory in patients with severe pneumonia. A number of recent studies and guidelines addressing these issues have been published, and they will be reviewed in this article.