Antibiotic therapy, supportive treatment and management of immunomodulation-inflammation response in community acquired pneumonia: review of recommendations

Immunomodulatory Effects of Fluoroquinolones in Community-Acquired Pneumonia-Associated Acute Respiratory Distress Syndrome

Community-acquired pneumonia is reported as one of the infectious diseases that leads to the development of acute respiratory distress syndrome. The innate immune system is the first line of defence against microbial invasion; however, its dysregulation during infection, resulting in an increased pathogen load, stimulates the over-secretion of chemokines and pro-inflammatory cytokines. This phenomenon causes damage to the epithelial-endothelial barrier of the pulmonary alveoli and the leakage of the intravascular protein into the alveolar lumen. Fluoroquinolones are synthetic antimicrobial agents with immunomodulatory properties that can inhibit bacterial proliferation as well as exhibit anti-inflammatory activities. It has been demonstrated that the structure of fluoroquinolones, particularly those with a cyclopropyl group, exerts immunomodulatory effects. Its capability to inhibit phosphodiesterase activity leads to the accumulation of intracellular cAMP, which subsequently enhances PKA activity, resulting in the inhibition of transcriptional factor NF-κB and the activation of CREB. Another mechanism reported is the inhibition of TLR and ERK signalling pathways. Although the sequence of events has not been completely understood, significant progress has been made in comprehending the specific mechanisms underlying the immunomodulatory effects of fluoroquinolones. Here, we review the indirect immunomodulatory effects of FQs as an alternative to empirical therapy in patients diagnosed with community-acquired pneumonia.

Cost-Saving Opportunities with an Oral and Intravenous Once-Daily Aminomethylcycline Antibiotic for Hospitalized Patients with Community-Acquired Bacterial Pneumonia: Findings from Decision-Analytic Models

BACKGROUND

The most frequently prescribed regimens for the treatment of hospitalized adults with suspected or documented community-acquired bacterial pneumonia (CABP), an acute bacterial infection of the pulmonary parenchyma, are ceftriaxone plus a macrolide, or a respiratory fluoroquinolone. Although these regimens are consistent with expert guidelines, there are growing concerns regarding their safety and efficacy. Omadacycline is a once-daily antibiotic with oral and intravenous (IV) formulations; it was recently approved in the United States for the treatment of adults with CABP.

OBJECTIVE

To estimate the cost impact of shortening hospital stay or avoiding hospitalization when using a treatment with an IV and an oral formulation, such as omadacycline, versus an IV-only drug regimen, such as ceftriaxone plus a macrolide, in adults with CABP who are not candidates for respiratory fluoroquinolone therapy.

METHODS

We developed 2 conceptual healthcare decision models to identify potential cost-saving opportunities in hospitalized adults with CABP who receive omadacycline versus ceftriaxone plus a macrolide. The early hospital discharge model examined the cost impact of shifting patients with CABP from inpatient treatment with ceftriaxone plus a macrolide to inpatient IV omadacycline treatment and early hospital discharge with oral omadacycline. The hospital-avoidance model examined the cost impact of omadacycline treatment in the outpatient setting in patients with CABP who have low disease severity. The models defined the upper range of the daily acquisition cost for omadacycline that conferred cost-savings relative to inpatient treatment with ceftriaxone plus a macrolide.

RESULTS

In the early hospital discharge model, omadacycline showed cost-savings with a 2-day hospital stay reduction if the daily cost of omadacycline was ≤$836, almost twice its wholesale acquisition cost. In the hospital-avoidance model, the daily omadacycline thresholds that still conferred cost-savings relative to inpatient ceftriaxone plus a macrolide ranged from $1302 to $1334, based on a daily wholesale acquisition cost of $450 for omadacycline, depending on the potential use of the emergency department and an observation unit.

CONCLUSION

The study findings show that the targeted use of omadacycline for the treatment of select patient populations with CABP could result in cost-savings relative to inpatient treatment with ceftriaxone plus a macrolide.

Microbial etiology of pneumonia in patients with decreased renal function

Background

Patients with renal impairment have altered immunity, which might cause vulnerability to specific pathogens and worsen pneumonia-related outcomes. Nonetheless, the microbiological features of pneumonia in patients with decreased renal function remain unknown.

Methods

Therefore, we conducted a retrospective cohort study enrolling adult patients hospitalized with pneumonia to assess this knowledge gap. The baseline estimated glomerular filtration rate (eGFR) and first sputum microbiology during hospitalization were used for statistical analyses.

Results

Overall, 1554 patients hospitalized with pneumonia (mean age, 76.1 ± 16.7) were included, and 162 patients had died at the end of hospitalization. The cutoff eGFR value predicting mortality was <55 mL/min/1.73 m², which defined decreased renal function in this study. Patients with decreased renal function demonstrated a significantly higher risk of fungi and Staphylococcus aureus (S. aureus) infection. On the other hand, this group of patients showed significantly higher neutrophil-to-lymphocyte ratio (NLR), which associated with higher mortality. Additionally, patients with S. aureus had a significantly lower eGFR, lymphocyte count and a higher NLR.

Conclusions

These findings suggested the altered immunity and vulnerability to S. aureus infection in patients with decreased renal function, which may be the underlying cause of worse outcomes of pneumonia in this group of patients.

Budget Impact of Omadacycline for the Treatment of Patients with Community-Acquired Bacterial Pneumonia in the United States from the Hospital Perspective

BACKGROUND

Community-acquired bacterial pneumonia (CABP) is an acute, lower respiratory bacterial infection. Despite advances in medical care, CABP remains associated with considerable morbidity, mortality, and healthcare costs; early empiric treatment is recommended by the Infectious Diseases Society of America and by the American Thoracic Society. Omadacycline is an oral and intravenous (IV) once-daily aminomethylcycline antibiotic that is approved in the United States for the treatment of adult patients with CABP.

OBJECTIVE

To estimate the budget impact of introducing omadacycline as a treatment option among patients with suspected or documented CABP from a US hospital perspective.

METHODS

A budget impact model was developed in Microsoft Excel^® 2010. Population, clinical, and cost inputs were based on the available literature, clinical trial data, and real-world evidence databases. Emergency departments and observation units were assumed to be hospital-owned as part of the analyses. Sensitivity analyses assessed the impact of key parameters on the model results, and scenario analyses were explored to analyze the budget impact of reducing length of hospital stay and avoiding hospitalization.

RESULTS

The introduction of omadacycline as a treatment resulted in a total budget increase of $20,643 over 3 years. This increase was mainly attributed to treatment acquisition costs. In a scenario where the length of hospital stay was reduced by 1 day (under the assumption that an antibiotic with IV and oral formulations can facilitate earlier discharge from inpatient care), the 3-year total budget decreased to $2384; reducing the hospital stay by 2 days resulted in 3-year cost-savings of $15,875. Shifting inpatient care to the outpatient setting with omadacycline resulted in 3-year cumulative cost-savings of $112,843.

CONCLUSION

This is the first omadacycline budget impact model developed for adult patients with suspected or documented CABP. The model projected a modest budget increase with the introduction of omadacycline, mainly due to treatment acquisition costs.

Management of community-acquired bacterial pneumonia in adults: Limitations of current antibiotics and future therapies

Community-acquired bacterial pneumonia (CABP) is one of the leading causes of morbidity and mortality in India and worldwide. Evidence indicates that Gram-positive, Gram-negative, and atypical bacteria are encountered with near-equal frequency. Despite guideline recommendations and antibiotic options for the management of CABP, burden of morbidity and mortality is high, which is attributable to a variety of factors. Failure of empirical therapy, probably because of insufficient microbial coverage, increasing bacterial resistance, and adverse effects of existing treatments, underlies the unsuccessful treatment of CABP, especially in India. Multiple novel therapies that have entered clinical development phases have potential to address some of these issues. This article discusses the current treatment guidelines in CABP, management limitations, and emerging potential treatment options in the management of CABP.

Evaluation of dynamic thiol/disulfide homeostasis in adult patients with community-acquired pneumonia

Background:

Community-acquired pneumonia is an important cause of mortality and morbidity in all age groups. Oxidant and antioxidant mechanisms play an important role in the pathogenesis and mortality of community-acquired pneumonia.

Objectives:

In this study, the role of thiol/disulfide homeostasis in the diagnosis and prognosis of community-acquired pneumonia was investigated.

Methods:

This was a prospective, controlled, observational study involving 73 community-acquired pneumonia patients and 68 healthy volunteers.

Results:

The native thiol and total thiol, which are thiol/disulfide homeostasis components, were significantly lower in the community-acquired pneumonia group. It was also found that the native thiol was lower in the high-risk community-acquired pneumonia group and that the native thiol and total thiol were associated with the Pneumonia Severity Index, CRB65 (confusion, respiratory rate, blood pressure, ⩾65 years old), and CURB65 (confusion, uremia, respiratory rate, blood pressure, ⩾65 years old) scores. The thiol compound levels were also associated with the C-reactive protein and procalcitonin levels. However, there was no significant difference between the survivors and non-survivors in terms of the thiol/disulfide homeostasis parameters.

Conclusion:

This study demonstrated the important role that oxidative stress plays in the pathogenesis of community-acquired pneumonia. The thiol/disulfide homeostasis biomarkers especially the native thiol and index-1 levels were significantly lower in patients with community-acquired pneumonia. Further studies are needed to investigate the diagnostic and prognostic value of thiol/disulfide homeostasis parameters in community-acquired pneumonia.