Discrepancy between antibiotics administered in acute exacerbations of chronic bronchitis and susceptibility of isolated pathogens in respiratory samples: multicentre study in the primary care setting

Prevalence, Pattern, Risks Factors and Consequences of Antibiotic Resistance in COPD: A Systematic Review

A concern of antibiotic use in chronic obstructive pulmonary disease (COPD) is the emergence and propagation of antimicrobial resistance (AMR). A systematic review was conducted to determine prevalence, pattern, risk factors and consequences of AMR in COPD. Bibliographic databases were searched from inception to November 2020, with no language restrictions, including studies of any design that included patients with COPD and reported prevalence and pattern of AMR. 2748 unique titles and abstracts were identified, of which 63 articles, comprising 26,387 patients, met inclusion criteria. Forty-four (69.8%) studies were performed during acute exacerbation. The median prevalence of AMR ranged from 0-100% for Pseudomonas aeruginosa, Moraxella catarrhalis, Klebsiella pneumoniae and Acinetobacter baumannii. Median resistance rates of H influenzae and S pneumoniae were lower by comparison, with maximum rates ≤40% and ≤46%, respectively, and higher for Staphylococcus aureus. There was a trend towards higher rates of AMR in patients with poorer lung function and greater incidence of previous antibiotic exposure and hospitalisation. The impact of AMR on mortality was unclear. Data regarding antimicrobial susceptibility testing techniques and the impact of other risk factors or consequences of AMR were variable or not reported. This is the first review to systematically unify data regarding AMR in COPD. AMR is relatively common and strategies to optimise antibiotic use could be valuable to prevent the currently under-investigated potential adverse consequences of AMR.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.2000957 .

Antibiotics in acute exacerbations of chronic bronchitis

Acute exacerbations of chronic bronchitis (AECB) are a major contributor to morbidity and mortality in patients with chronic obstructive pulmonary disease, accounting for more than 16 million physician office visits and over 500,000 hospitalizations in the USA each year. Antimicrobials have been recognized by clinical guidelines as an important component in the management of AECB with a bacterial etiology. The challenge of identifying patients most likely to benefit from antimicrobial therapy is difficult in the clinical setting. However, appropriate risk stratification of patients, and the use of antimicrobials within the correct spectrum and for a suitable duration, can improve clinical outcomes while minimizing induction of antimicrobial resistance. With an improved design in pharmacologic and clinical studies, differences can be appreciated among the various antimicrobial agents available to treat AECB. Factors to be considered in antimicrobial agent selection include local tissue penetration, effects on bacteriological eradication, duration of therapy, speed of resolution and prevention or delay of recurrences.

What are the most appropriate antibiotics for the treatment of acute exacerbation of chronic obstructive pulmonary disease? A therapeutic outcomes model

OBJECTIVES

To predict the clinical efficacy of several antimicrobials in the treatment of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

METHODS

A probability model (therapeutic outcomes model) was used to predict the likelihood of clinical success with particular antimicrobial agents in the treatment of patients with AECOPD, both in those clinically diagnosed (total patients with an AECOPD diagnosis regardless of the cause) and in those with bacterial AECOPD. The model took into account the following variables: (i) the proportion of patients with a clinical diagnosis of AECOPD and non-bacterial disease; (ii) likelihood of spontaneous resolution of a non-bacterial infection; (iii) prevalence of subcauses (different bacterial species) in bacterial AECOPD; (iv) rates of spontaneous resolution of bacterial AECOPD; and (v) antimicrobial efficacy of each antibiotic against each bacterial species (susceptibility based on PK/PD breakpoints).

RESULTS

Fluoroquinolones (levofloxacin, ciprofloxacin and moxifloxacin), a new third-generation oral cephalosporin (cefditoren) and high doses of amoxicillin/clavulanate were the antimicrobials with the highest predicted clinical efficacy both in mild-moderate AECOPD and in severe AECOPD (rates of 89.2% to 90.5% and 80.3% to 88.1%, respectively), whereas cefaclor, azithromycin, erythromycin and clarithromycin had the lowest predicted clinical efficacy (rates of 79.1% to 81.3% and 51.8% to 55.6% for mild-moderate and severe AECOPD, respectively), which was not much higher than that predicted for placebo (73.6% and 45.5%, respectively).

CONCLUSIONS

According to our model, fluoroquinolones (levofloxacin, ciprofloxacin and moxifloxacin), cefditoren and amoxicillin/clavulanate are the most appropriate antibiotics for the treatment of patients with AECOPD in terms of predicted clinical efficacy, with wide differences with respect to other antibiotics commonly used in the treatment of these patients, such as clarithromycin and azithromycin.