Treatment of acute exacerbations of chronic bronchitis: comparison of trovafloxacin and amoxicillin in a multicentre, double-blind, double-dummy study. Trovafloxacin Bronchitis Study Group

Role of infection and antimicrobial therapy in acute exacerbations of chronic obstructive pulmonary disease

Over the past several years, the significance of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) in patients with chronic airflow obstruction has become increasingly apparent due to the impact these episodes have on the natural history of disease. It is now known that frequent AECOPD can adversely affect a patient's health-related quality of life and short- and long-term pulmonary function. The economic burden of these episodes is also substantial. AECOPDs represent a local and systemic inflammatory response to both infectious and noninfectious stimuli, but the majority of episodes are likely related to bacterial or viral pathogens. Patients with purulent sputum and multiple symptoms are the most likely to benefit from treatment with antibiotics. Antibiotic choice should be tailored to the individual patient, taking into account the severity of the episode and host factors which might increase the likelihood of treatment failure. Current evidence suggests that therapeutic goals not only include resolution of the acute episode, but also prolonging the time to the next event. In the future, preventing exacerbations will likely become increasingly accepted as an additional therapeutic goal in chronic obstructive pulmonary disease patients.

Short-course antimicrobial therapy of respiratory tract infections

Accumulating evidence suggests that short-course (</=5 days, </=3 days for azithromycin) antimicrobial therapy may be at least as effective as and, in some cases, may be more effective than traditional longer (10- to 14-day) therapies. In group A beta-haemolytic streptococcal tonsillopharyngitis, short-course therapy with 6 days of amoxicillin, 4-5 days of a variety of cephalosporins and 5 days of clarithromycin modified-release and telithromycin are all reasonable alternatives to traditional 10-day penicillin therapy. Short-course (i.e. 3-day) azithromycin therapy is not recommended because of suboptimal clinical and bacteriological results compared with penicillin therapy, unless the dosage is doubled from 10 to 20 mg/kg/day for all 3 days. In uncomplicated acute suppurative otitis media, single-dose intramuscular ceftriaxone or 3- to 5-day short-course oral antimicrobial therapy should be effective in the majority (>/=80%) of patients. However, more research is clearly needed in the subpopulations of children <2 years of age and in those with unresponsive/recurrent disease, since short-course therapy may not be successful in the majority of these patients. In sinusitis, most short-course therapy data have involved maxillary disease in adult patients. Regimens have included 3 days of azithromycin or cotrimoxazole (trimethoprim/sulfamethoxazole) or 5 days of cefpodoxime, telithromycin, gatifloxacin, gemifloxacin or amoxicillin/clavulanic acid. Preliminary results are encouraging but more study is clearly needed, especially in the paediatric population. In acute bacterial exacerbations of chronic bronchitis, short-course therapy with a variety of cephalosporins, second-generation fluoroquinolones and advanced generation macrolides/azalides/ketolides are all reasonable alternatives to traditional 7- to 14-day therapies. Cost containment in antimicrobial therapy should involve consideration of short-course therapy in the management of the most common types of respiratory tract infections.

A critical review of the fluoroquinolones: focus on respiratory infections

The new fluoroquinolones (clinafloxacin, gatifloxacin, gemifloxacin, grepafloxacin, levofloxacin, moxifloxacin, sitafloxacin, sparfloxacin and trovafloxacin) offer excellent activity against Gram-negative bacilli and improved Gram-positive activity (e.g. against Streptococcus pneumoniae and Staphylococcus aureus) over ciprofloxacin. Ciprofloxacin still maintains the best in vitro activity against Pseudomonas aeruginosa. Clinafloxacin, gatifloxacin, moxifloxacin, sitafloxacin, sparfloxacin and trovafloxacin display improved activity against anaerobes (e.g. Bacteroides fragilis) versus ciprofloxacin. All of the new fluoroquinolones display excellent bioavailability and have longer serum half-lives than ciprofloxacin allowing for once daily dose administration. Clinical trials comparing the new fluoroquinolones to each other or to standard therapy have demonstrated good efficacy in a variety of community-acquired respiratory infections (e.g. pneumonia, acute exacerbations of chronic bronchitis and acute sinusitis). Limited data suggest that the new fluoroquinolones as a class may lead to better outcomes in community-acquired pneumonia and acute exacerbations of chronic bronchitis versus comparators. Several of these agents have either been withdrawn from the market, had their use severely restricted because of adverse effects (clinafloxacin because of phototoxicity and hypoglycaemia; grepafloxacin because of prolongation of the QTc and resultant torsades de pointes; sparfloxacin because of phototoxicity; and trovafloxacin because of hepatotoxicity), or were discontinued during developmental phases. The remaining fluoroquinolones such as gatifloxacin, gemifloxacin, levofloxacin and moxifloxacin have adverse effect profiles similar to ciprofloxacin. Extensive post-marketing safety surveillance data (as are available with ciprofloxacin and levofloxacin) are required for all new fluoroquinolones before safety can be definitively established. Drug interactions are limited; however, all fluoroquinolones interact with metal ion containing drugs (eg. antacids). The new fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin and moxifloxacin) offer several advantages over ciprofloxacin and are emerging as important therapeutic agents in the treatment of community-acquired respiratory infections. Their broad spectrum of activity which includes respiratory pathogens such as penicillin and macrolide resistant S. pneumoniae, favourable pharmacokinetic parameters, good bacteriological and clinical efficacy will lead to growing use of these agents in the treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute sinusitis. These agents may result in cost savings especially in situations where, because of their potent broad-spectrum activity and excellent bioavailability, they may be used orally in place of intravenous antibacterials. Prudent use of the new fluoroquinolones will be required to minimise the development of resistance to these agents.

Once daily oral ofloxacin in chronic obstructive pulmonary disease exacerbation requiring mechanical ventilation: a randomised placebo-controlled trial

BACKGROUND

The role of antibiotics in treatment of patients with moderate exacerbations of chronic obstructive pulmonary disease (COPD) is uncertain, but such treatment might be useful in very severe episodes. Our objective was to assess the effects of ofloxacin in patients with exacerbations of COPD who required mechanical ventilation.

METHODS

We did a prospective, randomised, double-blind, placebo-controlled trial in 93 patients with acute exacerbation of COPD who required mechanical ventilation. Patients were randomly assigned to receive oral ofloxacin 400 mg once daily (n=47) or placebo (46) for 10 days. Primary endpoints were death in hospital and need for an additional course of antibiotics, both separately and in combination. Analysis was by intention to treat.

FINDINGS

Three patients dropped out of the study. Two (4%) patients receiving ofloxacin died in hospital and ten (22%) did so in the placebo group (absolute risk reduction 17.5%, 95% CI 4.3-30.7, p=0.01). Treatment with ofloxacin significantly reduced the need for additional courses of antibiotics (28.4%, 12.9-43.9, p=0.0006). The combined frequency of death in hospital and need for additional antibiotics was significantly lower in patients assigned to ofloxacin than in those receiving placebo (45.9%, 29.1-62.7, p<0.0001). The duration of mechanical ventilation and hospital stay was significantly shorter in the ofloxacin group than in the placebo group (absolute difference 4.2 days, 95% CI 2.5-5.9; and 9.6 days, 3.4-12.8, respectively).

INTERPRETATION

New fluoroquinolones, such as ofloxacin, are beneficial in the treatment of COPD exacerbation requiring mechanical ventilation.

Selection of clinical, patient-reported, and economic end points in acute exacerbation of chronic bronchitis

BACKGROUND

Acute exacerbation of chronic bronchitis (AECB) places tremendous burden on patients, providers, employers, and health care systems.

OBJECTIVE

The purpose of this paper is to (1) review the clinical, patient-reported, and economic measures used to evaluate disease burden and treatment effectiveness in AECB in clinical trials and (2) propose a guide for selecting study end points in AECB that will help capture all the relevant disease outcomes.

METHODS

Two literature searches of the PubMed database were conducted to identify studies of clinical trials in bronchitis and evaluate the clinical, patient-reported, and economic end points used in these studies.

RESULTS

Previous studies have focused primarily on clinician-assessed outcomes, which do not capture the full impact of AECB on patients' lives. Reporting mechanisms for most end points have been inconsistent, limiting the ability to compare information or interpret differences. Previous studies have given limited attention to patient-reported outcomes and the economic implications of AECB. Patient-reported outcomes such as speed of symptom relief and work productivity are important parameters for assessing treatment effectiveness and provide practical information for treatment evaluation.

CONCLUSIONS

Additional research is needed to develop, examine, and validate patient-reported outcomes and the indirect costs of AECB. Measuring the relevant clinical, economic, and patient-reported outcomes in AECB patients using standardized methods may lead to a clearer understanding of the disease burden and the role, effectiveness, and cost-effectiveness of antibiotic treatment.

Efficacy of gemifloxacin in acute exacerbations of chronic bronchitis: a randomised, double-blind comparison with trovafloxacin

This randomised, double-blind, double-dummy, multinational study compared the efficacy and safety of gemifloxacin with trovafloxacin in the treatment of acute exacerbations of chronic bronchitis. There were 617 patients randomised: 303 to gemifloxacin and 314 to trovafloxacin. Clinical success rates at follow-up (clinical per-protocol population) were 91.5% for gemifloxacin and 87.6% for trovafloxacin. For the intent-to-treat population, the clinical efficacy of gemifloxacin was statistically significantly superior to that of trovafloxacin. In general, the in vitro activity of gemifloxacin against the major respiratory bacterial pathogens was superior to that of other antibiotics tested. Per-patient bacteriological success rates at follow-up (bacteriology per-protocol population) were 86.8% for gemifloxacin and 82.4% for trovafloxacin. Both agents were well tolerated. The clinical and bacteriological efficacy of a once-daily 5-day course of gemifloxacin is at least as good as that of a similar regimen of trovafloxacin in the treatment of acute exacerbations of chronic bronchitis.

Risk factors for acquisition of levofloxacin-resistant Streptococcus pneumoniae: a case-control study

A case-control study was conducted to identify the risk factors associated with levofloxacin-resistant Streptococcus pneumoniae (LRSP) colonization or infection. Twenty-seven case patients (patients with LRSP) were compared with 54 controls (patients with levofloxacin-susceptible S. pneumoniae). Risk factors that were significantly associated with LRSP colonization or infection, according to univariate analysis, included an older age (median age, 75 years for case patients versus 72.5 years for controls), residence in a nursing home (odds ratio [OR], 7.2), history of recent (OR, 4.6) and multiple (OR, 4.4) hospitalizations, prior exposure to fluoroquinolones (OR, 10.6) and beta-lactams (OR, 8.6), presence of chronic obstructive pulmonary disease (COPD; OR, 5.9), and nosocomial origin of the bacteria (OR, 5.7). Multivariate analysis showed that presence of COPD (OR, 10.3), nosocomial origin of the bacteria (OR, 16.2), residence in a nursing home (OR, 7.4), and exposure to fluoroquinolones (OR, 10.7) were independently associated with LRSP colonization or infection. Thus, a distinct group of patients with COPD is the reservoir of LRSP.

Gemifloxacin versus amoxicillin/clavulanate in the treatment of acute exacerbations of chronic bronchitis. The 070 Clinical Study group

Six hundred patients were evaluated in this randomized, double-blind, double-dummy, multicenter, parallel-group study comparing the efficacy and safety of gemifloxacin (320 mg once-daily for 5 days) and amoxicillin/clavulanate (500/125 mg three-times daily for 7 days) for the treatment of acute exacerbations of chronic bronchitis (AECB). Of note, more than 90% of study participants had stage 2 disease at study entry. The two drugs were found to be equally effective, with clinical success rates of 93.6% for gemifloxacin and 93.2% on amoxicillin/clavulanate (95% CI -3.9 to 4.6). Bacteriological success rates favored gemifloxacin (90.9% compared with 79.5% for amoxicillin/clavulanate; 95% CI -3.3 to 26.0); however, this difference was not statistically significant. Gemifloxacin and amoxicillin/clavulanate were both well tolerated. In summary, gemifloxacin was found to be well tolerated and effective for the treatment of AECB, suggesting it is well suited for empirical treatment of this common respiratory condition in the current clinical environment.

Do bacteria cause exacerbations of COPD?

Exacerbations of COPD, which include combinations of dyspnea, cough, wheezing, increased sputum production (and a change in its color to green or yellow), are common. The role of bacterial infection in causing these episodes and the value of antibiotic therapy for them are debated. An assessment of the microbiological studies indicates that conventional bacterial respiratory pathogens, such as Streptococcus pneumoniae and Haemophilus influenzae, are absent in about 50% of attacks. The frequency of isolating these organisms, which often colonize the bronchi of patients in stable condition, does not seem to increase during exacerbations, and their density typically remains unchanged. Serologic studies generally fail to show rises in antibody titers to H influenzae; the only report available demonstrates none to Haemophilus parainfluenzae; and the sole investigation of S pneumoniae is inconclusive. Trials with vaccines against S pneumoniae and H influenzae show no clear benefit in reducing exacerbations. The histologic findings of bronchial biopsies and cytologic studies of sputum show predominantly increased eosinophils, rather than neutrophils, contrary to what is expected with bacterial infections. The randomized, placebo-controlled trials generally show no benefit for antibiotics, but most have studied few patients. A meta-analysis of these demonstrated no clinically significant advantage to antimicrobial therapy. The largest trials suggest that antibiotics confer no advantage for mild episodes; with more severe attacks, in which patients should receive systemic corticosteroids, the addition of antimicrobial therapy is probably not helpful.

New Fluoroquinolones: Real and Potential Roles

The second-generation fluoroquinolones have enjoyed successful clinical use for more than 10 years in many countries, and they have a valued and proven record of safety and efficacy. However, deficiencies with respect to gram-positive and anaerobic organisms limit the use of these agents in respiratory, intra-abdominal, and pelvic infections. New, third-generation agents with dramatically increased activity against gram-positive and anaerobic bacteria--notably, Streptococcus pneumoniae and Bacteroides fragilis--have shown high rates of efficacy in pneumonia, bronchitis, and surgical and gynecologic infections. Although most of these new drugs produce similar clinical results, adverse reaction profiles differ and may influence therapeutic choices.

Safety of trovafloxacin in treatment of lower respiratory tract infections

Safety and toleration of oral trovafloxacin has been assessed in Phase III trials in patients with acute lower respiratory tract infections. Patients were treated orally with either trovafloxacin 100 or 200 mg (n=881) or a comparator (500 or 1000 mg amoxicillin, or 625 mg amoxicillin/clavulanic acid; n = 593). Adverse events were recorded in 112 (12.7%) trovafloxacin- and 74 (12.5%) comparator-treated patients. Frequency of effects on the autonomic nervous, musculoskeletal, respiratory, special senses, urinary and reproductive systems was <1%. Photosensitivity reactions were not reported in trovafloxacin-treated patients. Central or peripheral nervous system adverse effects (headache and dizziness) were slightly more common in trovafloxacin-treated patients (4.4% vs 1.9%). Patients treated with comparators experienced gastrointestinal events more frequently (6.1% vs 8.3%). Comparable incidences of adverse events were reported in patients > or = 65-years-old. Most events were mild to moderate in severity. Treatment was discontinued because of an adverse event in 18 (2%) trovafloxacin- and four (0.7%) comparator-treated patients. Despite the high prevalence of risk factors, serious adverse events were rare and the mortality rate over the 35-day study period was low: trovafloxacin 0.8%, comparator agents 1.5%. Laboratory test abnormalities were recorded in less than 1% of patients in either treatment group.