Antibiotics in the treatment of acute exacerbations of chronic bronchitis

Prognostic factors for clinical failure of exacerbations in elderly outpatients with moderate-to-severe COPD

Background

Acute exacerbations represent a significant burden for patients with moderate-to-severe chronic obstructive pulmonary disease. Each exacerbation episode is frequently associated with a lengthy recovery and impaired quality of life. Prognostic factors for outpatients that may predict poor outcome after treatment with antibiotics recommended in the guidelines, are not fully understood. We aimed to identify pretherapy factors predictive of clinical failure in elderly (≥60 years old) outpatients with acute Anthonisen type 1 exacerbations.

Trial registration

NCT00656747.

Methods

Based on the moxifloxacin in AECOPDs (acute exacerbations of chronic obstructive pulmonary disease) trial (MAESTRAL) database, this study evaluated pretherapy demographic, clinical, sputum bacteriological factors using multivariate logistic regression analysis, with internal validation by bootstrap replicates, to investigate their possible association with clinical failure at end of therapy (EOT) and 8 weeks posttherapy.

Results

The analyses found that the independent factors predicting clinical failure at EOT were more frequent exacerbations, increased respiratory rate and lower body temperature at exacerbation, treatment with long-acting anticholinergic drugs, and in vitro bacterial resistance to study drug. The independent factors predicting poor outcome at 8 weeks posttherapy included wheezing at preexacerbation, mild or moderate (vs extreme) sleep disturbances, lower body temperature at exacerbation, forced expiratory volume in 1 second <30%, lower body mass index, concomitant systemic corticosteroids for the current exacerbation, maintenance long-acting β₂-agonist and long-acting anticholinergic treatments, and positive sputum culture at EOT.

Conclusion

Several bacteriological, historical, treatment-related factors were identified as predictors of early (EOT) and later (8 weeks posttherapy) clinical failure in this older outpatient population with moderate-to-severe chronic obstructive pulmonary disease. These patients should be closely monitored and sputum cultures considered before and after treatment.

Antibiotics for treatment and prevention of exacerbations of chronic obstructive pulmonary disease

Acute exacerbations (AE) can be recurrent problems for patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) increasing morbidity and mortality. Evidence suggests that ≥50% of acute exacerbations involve bacteria requiring treatment with an antibiotic which should have high activity against the causative pathogens. However, sputum analysis is not a pre-requisite for antibiotic prescription in outpatients as results are delayed and patients are likely to be colonised with bacteria in the stable state. Clinicians rely on the clinical symptoms, sputum appearance and the patient's medical history to decide if an AE-COPD should be treated with antibiotics. This article reviews the available data of antibiotic trials in AE-COPD. Management of frequent exacerbators is particularly challenging for physicians. This may include antibiotic prophylaxis, especially macrolides because of anti-inflammatory properties; though successful in reducing exacerbations, concerns about resistance development remain. Inhalation of antibiotics achieves high local concentrations and minimal systemic exposure; therefore, it may represent an attractive alternative for antibiotic prophylaxis in certain COPD patients. Inhaled antibiotic prophylaxis has been successfully used in other respiratory conditions such as non-cystic fibrosis bronchiectasis which itself might be present in COPD patients who have chronic bacterial infection, particularly with Pseudomonas aeruginosa.

Antimicrobial resistance among respiratory Haemophilus influenzae isolates from pulmonology services over a six-year period

BACKGROUND

Respiratory tract infections (RTI) are frequently caused by Haemophilus influenzae. Widespread antibacterial resistance among respiratory microorganisms complicates empirical RTI treatment. Therefore, national data on antibiotic resistance for H. influenzae are important for guiding optimal antibiotic choice.

METHODS

The antibiotic susceptibility of H. influenzae strains isolated from respiratory specimens of patients admitted to the pulmonology services between 2005 and 2010 was assessed. Isolates were collected annually from 13 hospitals in the Netherlands as part of the national intramural antimicrobial resistance surveillance performed by the Dutch Working Group on Antibiotic Policy (SWAB). Breakpoints for resistance were in accordance with the criteria of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Trend analysis was performed using logistic regression analysis.

RESULTS

In total, 1606 H. influenzae strains were analyzed. The prevalence of antibiotic resistance to amoxicillin, co-amoxiclav, doxycycline, co-trimoxazole, and clarithromycin was stable over the 6-y period, and there was a trend towards a decrease in the prevalence of beta-lactamase-producing isolates. Regarding prevalences, no significant trends were observed.

CONCLUSIONS

Our study showed no significant changes in antibiotic resistance for H. influenzae isolated at different hospitals in the Netherlands over a 6-y period. Regular surveillance remains important in controlling the prevalence of resistance, since actual resistance data should be taken into account when the choice of an empiric antibiotic is made.

Moxifloxacin versus amoxicillin/clavulanic acid in outpatient acute exacerbations of COPD: MAESTRAL results

Bacterial infections causing acute exacerbations of chronic obstructive pulmonary disease (AECOPD) frequently require antibacterial treatment. More evidence is needed to guide antibiotic choice.

The Moxifloxacin in Acute Exacerbations of Chronic Bronchitis TriaL (MAESTRAL) was a multiregional, randomised, double-blind non-inferiority outpatient study. Patients were aged ≥60 yrs, with an Anthonisen type I exacerbation, a forced expiratory volume in 1 s <60% predicted and two or more exacerbations in the last year. Following stratification by steroid use patients received moxifloxacin 400 mg p.o. q.d. (5 days) or amoxicillin/clavulanic acid 875/125 mg p.o. b.i.d. (7 days). The primary end-point was clinical failure 8 weeks post-therapy in the per protocol population.

Moxifloxacin was noninferior to amoxicillin/clavulanic acid at the primary end-point (111 (20.6%) out of 538, versus 114 (22.0%) out of 518, respectively; 95% CI -5.89–3.83%). In patients with confirmed bacterial AECOPD, moxifloxacin led to significantly lower clinical failure rates than amoxicillin/clavulanic acid (in the intent-to-treat with pathogens, 62 (19.0%) out of 327 versus 85 (25.4%) out of 335, respectively; p=0.016). Confirmed bacterial eradication at end of therapy was associated with higher clinical cure rates at 8 weeks post-therapy overall (p=0.0014) and for moxifloxacin (p=0.003). Patients treated with oral corticosteroids had more severe disease and higher failure rates.

The MAESTRAL study showed that moxifloxacin was as effective as amoxicillin/clavulanic acid in the treatment of outpatients with AECOPD. Both therapies were well tolerated.

A novel study design for antibiotic trials in acute exacerbations of COPD: MAESTRAL methodology

Antibiotics, along with oral corticosteroids, are standard treatments for acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The ultimate aims of treatment are to minimize the impact of the current exacerbation, and by ensuring complete resolution, reduce the risk of relapse. In the absence of superiority studies of antibiotics in AECOPD, evidence of the relative efficacy of different drugs is lacking, and so it is difficult for physicians to select the most effective antibiotic. This paper describes the protocol and rationale for MAESTRAL (moxifloxacin in AECBs [acute exacerbation of chronic bronchitis] trial; www.clinicaltrials.gov: NCT00656747), one of the first antibiotic comparator trials designed to show superiority of one antibiotic over another in AECOPD. It is a prospective, multinational, multicenter, randomized, double-blind controlled study of moxifloxacin (400 mg PO [ per os] once daily for 5 days) vs amoxicillin/clavulanic acid (875/125 mg PO twice daily for 7 days) in outpatients with COPD and chronic bronchitis suffering from an exacerbation. MAESTRAL uses an innovative primary endpoint of clinical failure: the requirement for additional or alternate treatment for the exacerbation at 8 weeks after the end of antibiotic therapy, powered for superiority. Patients enrolled are those at high-risk of treatment failure, and all are experiencing an Anthonisen type I exacerbation. Patients are stratified according to oral corticosteroid use to control their effect across antibiotic treatment arms. Secondary endpoints include quality of life, symptom assessments and health care resource use.

Antibiotic therapy for exacerbations of chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is already the world's fourth most common cause of mortality and likely to become the third in a few year's time. Because it is an inflammatory airway disease with altered host immune response, infectious complications are frequent. Acute exacerbations of COPD (AECOPD) significantly worsen the patient's general health, accelerating disability. Each exacerbation leads progressively to further deterioration of lung function. Among the various causes of AECOPD, including viruses, bacteria and air pollution, a bacterial etiology is most common (50-69%). The management of AECOPD remains extremely challenging and places a heavy economic burden on health care institutions. The decision to administer antibiotics in AECOPD is multifactorial, the most important considerations being severity of the COPD stage and patient performance status, clinical symptoms (increased dyspnea, sputum volume and sputum purulence), severity of current and previous exacerbations, comorbidity and current smoking. Exacerbations which require hospital admission are associated with significant in-patient mortality. AECOPD patients presenting with worsening dyspnea, increased sputum volume and purulence should be offered antimicrobial therapy. If treating with antibiotics, treatment must include coverage for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in all cases, but other bacteria (such as Gram-negatives) may need to be covered depending on the condition of the patient. Antibiotics, particularly macrolides and fluoroquinolones, when administered under suitable conditions, shorten the clinical course and prevent severe deterioration. possible complications resulting from untreated severe AECOPD surpass the potential risks from the use of antibiotic therapy. Additional anti-inflammatory and immunomodulatory actions of some antibiotics may contribute to their efficacy in AECOPD.

Short-course fluoroquinolones in acute exacerbations of chronic bronchitis

It is estimated that 50-70% of acute exacerbations of chronic bronchitis (AECB) are caused by bacterial infections. Appropriate selection of antimicrobials may lead to better outcomes and reduced healthcare costs. Respiratory fluoroquinolones (moxifloxacin, levofloxacin and gemifloxacin) have a broad spectrum of activity against most AECB-causing pathogens and are used as first-line treatment in patients with comorbidity, severe airway obstruction or recurrent exacerbations. We review studies, identified through a MEDLINE search, that compared clinical efficacy and speed of recovery for short-course (≤ 5 days) fluoroquinolone therapy with commonly prescribed standard therapy (≥ 7 days). Among 177 studies reporting the use of fluoroquinolones for AECB treatment, 23 used a short-course regimen, shown to be at least as effective as standard therapy of 7 or more days duration. Furthermore, evidence suggests that short-course therapy offers faster resolution of symptoms, faster rate of recovery, fewer relapses, fewer and shorter hospitalizations, and longer time between recurrences.

Comparison between azithromycin and amoxicillin in the treatment of infectious exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

To compare the efficacy, safety, and tolerability of azithromycin and amoxicillin in the treatment of patients with infectious exacerbation of chronic obstructive pulmonary disease.

METHODS

This study was conducted at six medical centers across Brazil and included 109 patients from 33 to 82 years of age. Of those, 102 were randomized to receive either azithromycin (500 mg/day for three days, n = 49) or amoxicillin (500 mg every eight hours for ten days, n = 53). The patients were evaluated at the study outset, on day ten, and at one month. Based on the clinical evaluation of the signs and symptoms present on day ten and at one month, the outcomes were classified as cure, improvement, or treatment failure. The microbiological evaluation was made through the culture of sputum samples that were considered appropriate samples only after leukocyte counts and Gram staining. Secondary efficacy evaluations were made in order to analyze symptoms (cough, dyspnea, and expectoration) and pulmonary function.

RESULTS

There were no differences between the groups treated with azithromycin or amoxicillin in terms of the percentages of cases in which the outcomes were classified as cure or improvement: 85% vs. 78% (p = 0.368) on day ten; and 83% vs. 78% (p = 0.571) at one month. Similarly, there were no significant differences between the two groups in the secondary efficacy variables or the incidence of adverse effects.

CONCLUSION

Azithromycin and amoxicillin present similar efficacy and tolerability in the treatment of acute exacerbation of chronic obstructive pulmonary disease.

Pharmacokinetic and pharmacodynamic aspects of oral moxifloxacin 400 mg/day in elderly patients with acute exacerbation of chronic bronchitis

OBJECTIVE

To assess the pharmacokinetic and pharmacodynamic behaviour of moxifloxacin in 15 consecutive elderly patients with acute exacerbation of chronic bronchitis (AECB) treated with the fixed oral moxifloxacin 400 mg/day regimen with the intent of verifying which degree of exposure may be ensured by this standard regimen against AECB pathogens.

METHODS

This was an open-label, observational, pharmacokinetic-pharmacodynamic study. Blood samples were collected at steady state at appropriate intervals. Moxifloxacin plasma concentrations were analysed by means of high-performance liquid chromatography. Standard pharmacokinetic parameters and pharmacodynamic determinants (peak concentration [C(max)]/minimum inhibitory concentration [MIC], area under the plasma concentration-time curve during the 24-hour observational period [AUC(24)]/MIC, pharmacodynamic breakpoints [PDBPs]) were assessed.

RESULTS

The mean estimated pharmacokinetic parameters (C(max) 4.40 mg/L at 1.4 hours, AUC(24) 42.67 mg . h/L, elimination half-life 12.55 hours, total body clearance 0.16 L/h/kg) were generally similar to those observed in both young and elderly historic controls (except for higher-dose normalised C(max) and lower volume of distribution of the central compartment). Median C(max)/MIC and AUC(24)/MIC ratios for moxifloxacin in the fully assessable cases were, respectively, 67.5 and 823.9 against Streptococcus pneumoniae, 25 and 310.2 against Moraxella catharralis and 416.5 and 3647.5 against Haemophilus influenzae. Mean estimates of PDBP for achieving C(max)/MIC values of 12.2 and AUC(24)/MIC values of 125 were 0.36 and 0.35 mg/L, respectively.

CONCLUSION

In patients with AECB the pharmacokinetic behaviour of moxifloxacin is not significantly altered by aging processes. This is consistent with moxifloxacin being metabolised mainly by means of phase II hepatic reactions, the activity of which was shown not to decline with age. Both the pharmacokinetic and pharmacodynamic analyses suggest that moxifloxacin 400 mg/day may be a valid therapeutic approach in the treatment of AECB in the elderly. Of note, the unmodified pharmacokinetic behaviour with no need for age-related dosage adjustments combined with the once-daily administration favouring compliance and the low potential for drug-drug pharmacokinetic interactions in case of polytherapy, make moxifloxacin particularly attractive in the treatment of elderly subpopulations at a very high risk of AECB.