Ceftriaxone combination therapy versus respiratory fluoroquinolone monotherapy for community-acquired pneumonia: A meta-analysis

Community-Acquired Pneumonia: A Review

Importance

Community-acquired pneumonia (CAP) results in approximately 1.4 million emergency department visits, 740 000 hospitalizations, and 41 000 deaths in the US annually.

Observations

Community-acquired pneumonia can be diagnosed in a patient with 2 or more signs (eg, temperature >38 °C or ≤36 °C; leukocyte count <4000/μL or >10 000/μL) or symptoms (eg, new or increased cough or dyspnea) of pneumonia in conjunction with consistent radiographic findings (eg, air space density) without an alternative explanation. Up to 10% of patients with CAP are hospitalized; of those, up to 1 in 5 require intensive care. Older adults (≥65 years) and those with underlying lung disease, smoking, or immune suppression are at highest risk for CAP and complications of CAP, including sepsis, acute respiratory distress syndrome, and death. Only 38% of patients hospitalized with CAP have a pathogen identified. Of those patients, up to 40% have viruses identified as the likely cause of CAP, with Streptococcus pneumoniae identified in approximately 15% of patients with an identified etiology of the pneumonia. All patients with CAP should be tested for COVID-19 and influenza when these viruses are common in the community because their diagnosis may affect treatment (eg, antiviral therapy) and infection prevention strategies. If test results for influenza and COVID-19 are negative or when the pathogens are not likely etiologies, patients can be treated empirically to cover the most likely bacterial pathogens. When selecting empirical antibacterial therapy, clinicians should consider disease severity and evaluate the likelihood of a bacterial infection-or resistant infection-and risk of harm from overuse of antibacterial drugs. Hospitalized patients without risk factors for resistant bacteria can be treated with β-lactam/macrolide combination therapy, such as ceftriaxone combined with azithromycin, for a minimum of 3 days. Systemic corticosteroid administration within 24 hours of development of severe CAP may reduce 28-day mortality.

Conclusions

Community-acquired pneumonia is common and may result in sepsis, acute respiratory distress syndrome, or death. First-line therapy varies by disease severity and etiology. Hospitalized patients with suspected bacterial CAP and without risk factors for resistant bacteria can be treated with β-lactam/macrolide combination therapy, such as ceftriaxone combined with azithromycin, for a minimum of 3 days.

Comparison of Empiric Antibiotic Treatment Regimens for Hospitalized, Non-severe Community-acquired Pneumonia: A Retrospective, Multicenter Cohort Study

PURPOSE

Consensus guidelines for hospitalized, non-severe community-acquired pneumonia (CAP) recommend empiric macrolide + β-lactam or respiratory fluoroquinolone monotherapy in patients with no risk factors for resistant organisms. In patients with allergies or contraindications, doxycycline + β-lactam is a recommended alternative. The purpose of this study was to compare differences in outcomes among guideline-recommended regimens in this population.

METHODS

This retrospective, multicenter cohort study included patients ≥18 years of age with CAP who received respiratory fluoroquinolone monotherapy, empiric macrolide + β-lactam, or doxycycline + β-lactam. Major exclusion criteria included patients with immunocompromising conditions, requiring vasopressors or invasive mechanical ventilation within 48 hours of admission, and receiving less than 2 days of total antibiotic therapy. The primary outcome was in-hospital mortality. Secondary outcomes included clinical failure, 14- and 30-day hospital readmission, and hospital length of stay. Safety outcomes included incidence of new Clostridioides difficile infection and aortic aneurysm ruptures.

FINDINGS

Of 4685 included patients, 1722 patients received empiric respiratory fluoroquinolone monotherapy, 159 received empiric doxycycline + β-lactam, and 2804 received empiric macrolide + β-lactam. Incidence of in-hospital mortality was not observed to be significantly different among empiric regimens (doxycycline + β-lactam group: 1.9% vs macrolide + β-lactam: 1.9% vs respiratory fluoroquinolone monotherapy: 1.5%, P = 0.588). No secondary outcomes were observed to differ significantly among groups.

IMPLICATIONS

We observed no differences in clinical or safety outcomes among three guideline-recommended empiric CAP regimens. Empiric doxycycline + β-lactam may be a safe empiric regimen for hospitalized CAP patients with non-severe CAP, although additional research is needed to corroborate these observations with larger samples.

Effects of antibiotics ceftriaxone and levofloxacin on the growth of Lucilia sericata (Diptera: Calliphoridae)

Lucilia sericata is one of the most studied species in forensic entomology due to its widespread distribution, forensic importance as well as medical use. The growth and development stage of maggots is often used to determine the post-mortem interval in forensic cases. L. sericata can cause myiasis in humans who are not able to maintain personal hygiene due to age or medical condition and can therefore be used to determine the time period of neglect. The influence of the temperature on the maggot development has been examined in various studies. Different examinations on the effects of toxic substances on the maggot development and survival have been conducted in order to test the influence and resulting deviations. In this study, the effects of different therapeutical doses of the antibiotics ceftriaxone and levofloxacin were examined on L. sericata in order to determine and compare deviations in maggot development and survival. The used antibiotics did not significantly influence the maggot weight and length. A significant delay in the time of pupation has been determined in the treatments with high concentrations of levofloxacin. The mortality was significantly increased in all treatments with antibiotics compared to the control, whereby the survivability of all treatments remained over 80%. Because of the high doses needed to produce an effect, we concluded that an overestimation of the post-mortem interval is unlikely but higher antibiotic concentrations or possible interactions with other medications could increase the maggot development time.

Respiratory fluoroquinolone monotherapy vs. β-lactam plus macrolide combination therapy for hospitalized adults with community-acquired pneumonia: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Guidelines recommend respiratory fluoroquinolone monotherapy or β-lactam plus macrolide combination therapy as first-line options for hospitalized adults with mild-to-moderate community-acquired pneumonia (CAP). Efficacy of these regimens has not been adequately evaluated.

METHODS

A systematic review of randomized controlled trials (RCTs) comparing respiratory fluoroquinolone monotherapy and β-lactam plus macrolide combination therapy in hospitalised adults with CAP was performed. A meta-analysis was performed using a random effects model. The primary outcome was clinical cure rate. Quality of evidence (QoE) was evaluated using GRADE methodology.

RESULTS

A total of 4140 participants in 18 RCTs were included. Levofloxacin (11 trials) or moxifloxacin (6 trials) were the predominant respiratory fluoroquinolones evaluated, and the β-lactam plus macrolide group used ceftriaxone plus a macrolide (10 trials), cefuroxime plus azithromycin (5 trials), and amoxicillin/clavulanate plus a macrolide (2 trials). Patients receiving respiratory fluoroquinolone monotherapy had a significantly higher clinical cure rate (86.5% vs. 81.5%; odds ratio [OR] 1.47; 95% confidence interval [95% CI: 1.17-1.83]; P = 0.0008; I2 = 0%; 17 RCTs; moderate QoE) and microbiological eradication rate (86.0% vs. 81.0%; OR 1.51 [95% CI: 1.00-2.26]; P = 0.05; I2 = 0%; 15 RCTs; moderate QoE) than patients receiving β-lactam plus macrolide combination therapy. All-cause mortality (7.2% vs. 7.7%; OR 0.88 [95% CI: 0.67-1.17]; I2 = 0%; low QoE) and adverse events (24.8% vs. 28.1%; OR 0.87 [95% CI: 0.69-1.09]; I2 = 0%; low QoE] were similar in the two groups.

CONCLUSION

Respiratory fluoroquinolone monotherapy demonstrated an advantage in clinical cure and microbiological eradication; however, it did not impact mortality.

The Global Burden of Community-Acquired Pneumonia in Adults, Encompassing Invasive Pneumococcal Disease and the Prevalence of Its Associated Cardiovascular Events, with a Focus on Pneumolysin and Macrolide Antibiotics in Pathogenesis and Therapy

Despite innovative advances in anti-infective therapies and vaccine development technologies, community-acquired pneumonia (CAP) remains the most persistent cause of infection-related mortality globally. Confronting the ongoing threat posed by Streptococcus pneumoniae (the pneumococcus), the most common bacterial cause of CAP, particularly to the non-immune elderly, remains challenging due to the propensity of the elderly to develop invasive pneumococcal disease (IPD), together with the predilection of the pathogen for the heart. The resultant development of often fatal cardiovascular events (CVEs), particularly during the first seven days of acute infection, is now recognized as a relatively common complication of IPD. The current review represents an update on the prevalence and types of CVEs associated with acute bacterial CAP, particularly IPD. In addition, it is focused on recent insights into the involvement of the pneumococcal pore-forming toxin, pneumolysin (Ply), in subverting host immune defenses, particularly the protective functions of the alveolar macrophage during early-stage disease. This, in turn, enables extra-pulmonary dissemination of the pathogen, leading to cardiac invasion, cardiotoxicity and myocardial dysfunction. The review concludes with an overview of the current status of macrolide antibiotics in the treatment of bacterial CAP in general, as well as severe pneumococcal CAP, including a consideration of the mechanisms by which these agents inhibit the production of Ply by macrolide-resistant strains of the pathogen.

Effects of antibiotics ceftriaxone and levofloxacin on the growth of Calliphora vomitoria L. (Diptera: Calliphoridae) and effects on the determination of the post-mortem interval

The determination of the post-mortem interval (PMI) is one of the main tasks of forensic entomology, where growth and stages of development of arthropods are used for PMI determination. It is well acknowledged that maggot development is significantly influenced by temperature. Attention has also been paid to the microbial populations of the cadaver, because toxic substances contained in the substrate can influence the microorganisms and affect arthropods growth and development. However, little is known about the influence of antibiotics taken during lifetime of a person on insect development after that persons death. The aim of this study was to test the hypothesis that the antibiotics ceftriaxone and levofloxacin cause inhibition of growth and delay of pupation of the blow fly Calliphora vomitoria, which would then lead to an incorrect determination of the post-mortem interval in forensic cases. It was found that maggot development was delayed by levofloxacin mixed in minced pork, where a mixture of both antibiotics increased this effect. The maggot growth in the samples with ceftriaxone was not delayed. Pupation was delayed in treatments with a mixture of both antibiotics. The mortality was reduced by separate or combined application of ceftriaxone and levofloxacin, which we attribute to a bactericidal effect of the antibiotics on maggot pathogens. Depending on the concentration of the antibiotics, an underestimation of the post-mortem interval between 24 and 48 h could be suspected. We conclude that antibiotics need to be considered if instar stages are to be used to determine the PMI and that some antibiotics may improve the breeding conditions of maggots.

Infections in Older Adults

Infections in elderly patients can prove diagnostically challenging. Age-related factors affecting the immune system in older individuals contribute to nonspecific presentations. Other age-related factors and chronic conditions have symptoms that may or may not point to an infectious diagnosis. Delay in administration of antimicrobials can lead to poor outcomes; however, unnecessary administration of antimicrobials can lead to increased morbidity and contribute to the emergence of multidrug-resistant organisms. Careful clinical assessment and consideration of patient history and risk factors is crucial. When necessary, antimicrobials should be chosen that are appropriate for the diagnosis and deescalated as soon as possible.

Effect of Combined β-Lactam/Macrolide Therapy on Mortality According to the Microbial Etiology and Inflammatory Status of Patients With Community-Acquired Pneumonia

BACKGROUND

Antibiotic combinations that include macrolides have shown lower mortality rates than β-lactams in monotherapy or combined with fluoroquinolones in patients with community-acquired pneumonia (CAP). However, this effect has not been studied according to the levels of C-reactive protein in CAP with identified microbial cause. In patients with CAP and known microbial cause we aimed to evaluate 30-day mortality of a β-lactam plus macrolide (BL + M) compared with a fluoroquinolone alone or with a β-lactam (FQ ± BL).

METHODS

We analyzed a prospective observational cohort of patients with CAP admitted to the Hospital Clinic of Barcelona between 1996 and 2016. We included only patients with known microbial cause.

RESULTS

Of 1,715 patients (29%) with known etiology, a total of 932 patients (54%) received BL + M. Despite lower crude mortality in the BL + M group in the overall population (BL + M, 5% vs FQ ± BL, 8%; P = .015), after adjustment by a propensity score and baseline characteristics, the combination of BL + M had a protective effect on mortality only in patients with high inflammatory response (C-reactive protein, > 15 mg/dL) and pneumococcal CAP (adjusted OR, 0.28; 95% CI, 0.09-0.93). No benefits on mortality were observed for the population without high inflammatory response and pneumococcal CAP or with other etiologies.

CONCLUSIONS

The combination of a β-lactam with a macrolide was associated with decreased mortality in patients with pneumococcal CAP and in patients with high systemic inflammatory response. When both factors occurred together, BL + M was protective for mortality in the multivariate analysis.