Antibiotics as immunomodulators: a potential pharmacologic approach for ARDS treatment

First described in the mid-1960s, acute respiratory distress syndrome (ARDS) is a life-threatening form of respiratory failure with an overall mortality rate of approximately 40%. Despite significant advances in the understanding and treatment of ARDS, no substantive pharmacologic therapy has proven to be beneficial, and current management continues to be primarily supportive. Beyond their antibacterial activity, several antibiotics such as macrolides and tetracyclines exert pleiotropic immunomodulatory effects that might be able to rectify the dysregulated inflammatory response present in patients with ARDS. This review aims to provide an overview of preclinical and clinical studies that describe the immunomodulatory effects of antibiotics in ARDS. Moreover, the underlying mechanisms of their immunomodulatory properties will be discussed. Further studies are necessary to investigate their full therapeutic potential and to identify ARDS phenotypes which are most likely to benefit from their immunomodulatory effects.

In vitro susceptibility of common bacterial pathogens causing respiratory tract infections in Canada to lefamulin, a new pleuromutilin

Background

Community-acquired pneumonia (CAP) is a significant global health concern. Pathogens causing CAP demonstrate increasing resistance to commonly prescribed empiric treatments. Resistance in Streptococcus pneumoniae, the most prevalent bacterial cause of CAP, has been increasing worldwide, highlighting the need for improved antibacterial agents. Lefamulin, a novel pleuromutilin, is a recently approved therapeutic agent highly active against many lower respiratory tract pathogens. However, to date minimal data are available to describe the in vitro activity of lefamulin against bacterial isolates associated with CAP.

Methods

Common bacterial causes of CAP obtained from both lower respiratory and blood specimen isolates cultured by hospital laboratories across Canada were submitted to the annual CANWARD study's coordinating laboratory in Winnipeg, Canada, from January 2015 to October 2018. A total of 876 bacterial isolates were tested against lefamulin and comparator agents using the Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method, and minimum inhibitory concentrations (MICs) were interpreted using accepted breakpoints.

Results

All S. pneumoniae isolates tested from both respiratory (n = 315) and blood specimens (n = 167) were susceptible to lefamulin (MIC ≤0.5 μg/mL), including isolates resistant to penicillins, clarithromycin, doxycycline, and trimethoprim-sulfamethoxazole. Lefamulin also inhibited 99.0% of Haemophilus influenzae isolates (regardless of β-lactamase production) (99 specimens; MIC ≤2 μg/mL) and 95.7% of methicillin-susceptible Staphylococcus aureus (MSSA) (MIC ≤0.25 μg/mL; 70 specimens) at their susceptible breakpoints. Conclusions: Lefamulin demonstrated potent in vitro activity against all respiratory isolates tested and may represent a significant advancement in empiric treatment options for CAP.

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

Association Between Initial Route of Fluoroquinolone Administration and Outcomes in Patients Hospitalized for Community-acquired Pneumonia

BACKGROUND

Fluoroquinolones have equivalent oral and intravenous bioavailability, but hospitalized patients with community-acquired pneumonia (CAP) generally are treated intravenously. Our objectives were to compare outcomes of hospitalized CAP patients initially receiving intravenous vs oral respiratory fluoroquinolones.

METHODS

This was a retrospective cohort study utilizing data from 340 hospitals involving CAP patients admitted to a non-intensive care unit (ICU) setting from 2007 to 2010, who received intravenous or oral levofloxacin or moxifloxacin. The primary outcome was in-hospital mortality. Secondary outcomes included clinical deterioration (transfer to ICU, initiation of vasopressors, or invasive mechanical ventilation [IMV] initiated after the second hospital day), antibiotic escalation, length of stay (LOS), and cost.

RESULTS

Of 36 405 patients who met inclusion criteria, 34 200 (94%) initially received intravenous treatment and 2205 (6%) received oral treatment. Patients who received oral fluoroquinolones had lower unadjusted mortality (1.4% vs 2.5%; P = .002), and shorter mean LOS (5.0 vs 5.3; P < .001). Multivariable models using stabilized inverse propensity treatment weighting revealed lower rates of antibiotic escalation for oral vs intravenous therapy (odds ratio [OR], 0.84; 95% confidence interval [CI], .74-.96) but no differences in hospital mortality (OR, 0.82; 95% CI, .58-1.15), LOS (difference in days 0.03; 95% CI, -.09-.15), cost (difference in $-7.7; 95% CI, -197.4-182.0), late ICU admission (OR, 1.04; 95% CI, .80-1.36), late IMV (OR, 1.17; 95% CI, .87-1.56), or late vasopressor use (OR, 0.94; 95% CI, .68-1.30).

CONCLUSIONS

Among hospitalized patients who received fluoroquinolones for CAP, there was no association between initial route of administration and outcomes. More patients may be treated orally without worsening outcomes.

Risk of severe dysglycemia among diabetic patients receiving levofloxacin, ciprofloxacin, or moxifloxacin in Taiwan

BACKGROUND

Observational studies and fatal case reports raise concern about the safety of severe dysglycemia associated with fluoroquinolone use. The objective of this study was to assess the risk of severe dysglycemia among diabetic patients who received different fluoroquinolones.

METHODS

In a population-based inception cohort study of diabetic patients covering the period from January 2006 to November 2007, outpatient new users of levofloxacin, ciprofloxacin, moxifloxacin, cephalosporins, and macrolides orally were identified. Study events were defined as emergency department visits or hospitalization for dysglycemia within 30 days following the initiation of antibiotic therapy. Results were analyzed with adjusted multinomial propensity score.

RESULTS

A total of 78 433 diabetic patients receiving the antibiotics of interest were included in the study. The absolute risk of hyperglycemia per 1000 persons was 6.9 for moxifloxacin and 1.6 for macrolides. In contrast, the risk of hypoglycemia was 10.0 for moxifloxacin and 3.7 for macrolides. The adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of levofloxacin, ciprofloxacin, and moxifloxacin compared with macrolides were 1.75 (1.12-2.73), 1.87 (1.20-2.93), and 2.48 (1.50-4.12), respectively, for hyperglycemia and 1.79 (1.33-2.42), 1.46 (1.07-2.00), and 2.13 (1.44-3.14), respectively, for hypoglycemia. Patients taking moxifloxacin faced a significantly higher risk of hypoglycemia than those receiving ciprofloxacin. A significant increase in the risk of hypoglycemia was also observed among patients receiving moxifloxacin concomitantly with insulin (AOR, 2.28; 95% CI, 1.22-4.24).

CONCLUSIONS

Diabetics using oral fluoroquinolones faced greater risk of severe dysglycemia. The risk of hypoglycemia varied according to the type of fluoroquinolone administered, and was most commonly associated with moxifloxacin.

[Update of pneumonia in the elderly]

The incidence of pneumonia increases with age and contributes to morbidity and mortality in the elderly. In our setting, pneumonia is the sixth leading cause of death and the fourth most common diagnosis at discharge from acute hospitals. This article reviews current concepts in management of pneumonia in the elderly: healthcare-associated pneumonia, aspiration and oropharyngeal dysphagia, risk stratification, and indications of radiological, microbiological and biological markers. We present current evidence on antibiotic treatment (when to start, empirical coverage, duration, new drugs and combinations) and adjuvant treatment (steroids, early mobilization, oral hygiene, prevention and treatment of aspiration and cardiac complications). We emphasize preventive aspects and considerations regarding palliative treatment.

Empirical use of fluoroquinolones improves the survival of critically ill patients with tuberculosis mimicking severe pneumonia

Introduction

Empirical use of fluoroquinolones may delay the initiation of appropriate therapy for tuberculosis (TB). This study aimed to evaluate the impact of empirical fluoroquinolone use on the survival of patients with pulmonary TB that mimicked severe community-acquired pneumonia (CAP) requiring intensive care.

Methods

Patients aged >18 years with culture-confirmed pulmonary TB who presented as severe CAP and were admitted to the ICU were divided into fluoroquinolone (FQ) and nonfluoroquinolone (non-FQ) groups based on the type of empirical antibiotics used. Those patients with previous anti-TB treatment or those who died within 3 days of hospitalization were excluded. The primary end point was 100-day survival.

Results

Of the 77 patients identified, 43 (56%) were in the FQ group and 34 (44%) were in the non-FQ group. The two groups had no statistically significant difference in co-morbidities (95% vs. 97%, P > 0.99) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores (21.2 ± 7.1 vs. 22.5 ± 7.5, P = 0.46) on ICU admission. Overall, 91% and 82% of patients in the FQ and non-FQ groups, respectively, had sputum examinations for TB within 1 week of admission (P = 0.46), and results were positive in 7% and 15% (P = 0.47), respectively. For both groups, 29% received appropriate anti-TB therapy within 2 weeks after ICU admission. The 100-day mortality rate was 40% and 68% for the FQ and non-FQ groups, respectively (P = 0.02). By Cox regression analysis, APACHE score <20, no bacteremia during the ICU stay, and empirical fluoroquinolone use were independently associated with survival.

Conclusion

Empirical use of fluoroquinolones may improve the survival of ICU patients admitted for pulmonary TB mimicking severe CAP.

Indications of antibiotic prophylaxis in dental practice- review

Antibiotics are frequently used in dental practice. Clinical and bacteriological epidemiological factors determine the indications of antibiotics in dentistry. Antibiotics are used in addition to appropriate treatment to aid the host defences in the elimination of remaining bacteria. It is indicated when there is evidence of clinical sign involvement and spread of infection. Antibiotics are prescribed in dental practice for treating odontoge nic infections, non-odontogenic infections, as prophylaxis against focal and local infection. Special care needs to be addressed to patients with organ transplants, poorly controlled diabetes and pregnancy. Antibiotics should be used only as an adjunct to dental treatment and never alone as the first line of care. The present paper reviews the indications of antibiotics in dental practice.