Efficacy of Doxycycline for Mild-to-Moderate Community-Acquired Pneumonia in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

High Rates of Nonsusceptibility to Common Oral Antibiotics in Streptococcus pneumoniae Clinical Isolates From the United States (2019-2021)

Streptococcus pneumoniae isolates from the United States (n = 1038; 2019-2021) were susceptible to omadacycline (99.8%), levofloxacin (99.7%), and ceftriaxone (98.1%), whereas doxycycline (80.2%), oral penicillin (63.5%), cefpodoxime (76.8%), and azithromycin (54.4%) activity was limited. Tet(M) did not affect omadacycline activity but altered activity of older tetracyclines including doxycycline, suggesting omadacycline is an important option for treatment of community-acquired bacterial pneumonia.

Doxycycline prophylaxis for the prevention of sexually transmitted infections: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To investigate the effects of doxycycline pre- and post-exposure prophylaxis (doxy-PrEP/PEP) on bacterial sexually transmitted infections (STIs) by conducting a systematic review and meta-analysis.

METHODS

PubMed, Embase, and CENTRAL were searched for randomized controlled trials (RCTs), including ongoing studies published until November 7, 2023. Our primary endpoint was the incidence of bacterial STIs measured as the number of visits with an STI per total number of visits. Random-effects model was used to estimate pooled effect sizes. The study was registered with PROSPERO, CRD42023478486.

RESULTS

We identified six eligible studies containing data from seven articles and four conference abstracts, enrolling men who have sex with men (MSM), transgender women (TGW), and cisgender women (CGW). The pooled analysis of 1,766 participants with 602 newly diagnosed STIs showed a 56% decrease in the overall STI incidence using doxy-PrEP/PEP (RR = 0.44; 95% CI: 0.30-0.65; I2 = 73%). For doxy-PEP, including MSM and TGW only, the RR observed for overall STI incidence was 0.40 (95% CI: 0.28-0.57; I² = 37%), 0.19 (95% CI: 0.08-0.44; I² = 39%) for chlamydia, 0.23 (0.14-0.36; I² = 0%) for syphilis and 0.55 (95% CI: 0.34-0.87; I² = 41%) for gonorrhea. No serious adverse events were reported in the studies. The certainty of evidence regarding the efficacy of doxy-PEP among MSM and TGW was graded as high.

CONCLUSION

Doxy-PEP significantly reduces the number of new cases of chlamydia and syphilis and is potentially effective against gonorrhea, influenced by local resistance patterns. Thus, it is a promising tool in the prevention of bacterial STIs among MSM and TGW.

Significant Publications on Infectious Diseases Pharmacotherapy in 2022

Purpose: To provide summarization of the most significant infectious diseases (ID) pharmacotherapy articles published in peer-reviewed literature in 2022. Summary: Members of the Houston Infectious Diseases Network (HIDN) nominated notable articles providing significant contributions to ID pharmacotherapy in 2022. Article nominations included those pertaining to general ID, as well as those including coronavirus disease 2019 (COVID-19), and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pharmacotherapy. A total of 71 articles were nominated by HIDN. Members: 68 articles pertaining to general ID pharmacotherapy and 3 articles focusing on HIV/AIDS. To aid selection of the most these most notable articles of 2022, a survey was created and distributed to members of the Society of Infectious Diseases Pharmacists (SIDP). Of the 153 SIDP members who participated in the survey, there were 128 recorded votes for the top 10 general ID pharmacotherapy articles and 30 votes recorded for the top HIV/AIDS article. The most notable publications are summarized. Conclusion: Post pandemic significant advances in antimicrobial stewardship and infectious disease states continues to occur in a world recently focused on the coronavirus disease 2019 (COVID-19) global pandemic. Continuous growth in publication of ID-related articles over the past year lends towards the aims of this review to aid clinicians in remaining current on key practice-changing ID pharmacotherapy publications from 2022.

Interaction of the Atypical Tetracyclines Chelocardin and Amidochelocardin with Renal Drug Transporters

Antimicrobial resistance is expected to increase mortality rates by up to several million deaths per year by 2050 without new treatment options at hand. Recently, we characterized the pharmacokinetic (PK) and pharmacodynamic properties of two atypical tetracyclines, chelocardin (CHD) and amidochelocardin (CDCHD) that exhibit no cross-resistance with clinically used antibacterials. Both compounds were preferentially renally cleared and demonstrated pronounced effects in an ascending urinary tract infection model against E. coli. Renal drug transporters are known to influence clearance into the urine. In particular, inhibition of apical transporters in renal tubular epithelial cells can lead to intracellular accumulation and potential cell toxicity, whereas inhibition of basolateral transporters can cause a higher systemic exposure. Here, selected murine and human organic cation (Oct), organic anion (Oat), and efflux transporters were studied to elucidate interactions with CHD and CDCHD underlying their PK behavior. CHD exhibited stronger inhibitory effects on mOat1 and mOat3 and their human homologues hOAT1 and hOAT3 compared to CDCHD. While CHD was a substrate of mOat3 and mOct1, CDCHD was not. By contrast, no inhibitory effect was observed on Octs. CDCHD rather appeared to foster enhanced substrate transport on mOct1. CHD and CDCHD inhibited the efflux transporter hMRP2 on the apical side. In summary, the substrate nature of CHD in conjunction with its autoinhibition toward mOat3 rationalizes the distinct urine concentration profile compared to CDCHD that was previously observed in vivo. Further studies are needed to investigate the accumulation in renal tubular cells and the nephrotoxicity risk.

miR-486-5p predicted adverse outcomes of SCAP and regulated K. pneumonia infection via FOXO1

PURPOSE

Severe community-acquired pneumonia (SCAP) is a common respiratory system disease with rapid development and high mortality. Exploring effective biomarkers for early detection and development prediction of SCAP is of urgent need. The function of miR-486-5p in SCAP diagnosis and prognosis was evaluated to identify a promising biomarker for SCAP.

PATIENTS AND METHODS

The serum miR-486-5p in 83 patients with SCAP, 52 healthy individuals, and 68 patients with mild CAP (MCAP) patients were analyzed by PCR. ROC analysis estimated miR-486-5p in screening SCAP, and the Kaplan-Meier and Cox regression analyses evaluated the predictive value of miR-486-5p. The risk factors for MCAP patients developing SCAP were assessed by logistic analysis. The alveolar epithelial cell was treated with Klebsiella pneumonia to mimic the occurrence of SCAP. The targeting mechanism underlying miR-486-5p was evaluated by luciferase reporter assay.

RESULTS

Upregulated serum miR-486-5p screened SCAP from healthy individuals and MCAP patients with high sensitivity and specificity. Increasing serum miR-486-5p predicted the poor outcomes of SCAP and served as a risk factor for MCAP developing into SCAP. K. pneumonia induced suppressed proliferation, significant inflammation and oxidative stress in alveolar epithelial cells, and silencing miR-486-5p attenuated it. miR-486-5p negatively regulated FOXO1, and the knockdown of FOXO1 reversed the effect of miR-486-5p in K. pneumonia-treated alveolar epithelial cells.

CONCLUSION

miR-486-5p acted as a biomarker for the screening and monitoring of SCAP and predicting the malignancy of MCAP. Silencing miR-486-5p alleviated inflammation and oxidative stress induced by K. pneumonia via negatively modulating FOXO1.

Identifying the Best Initial Oral Antibiotics for Adults with Community-Acquired Pneumonia: A Network Meta-Analysis

BACKGROUND

The objective of this network meta-analysis was to compare rates of clinical response and mortality for empiric oral antibiotic regimens in adults with mild-moderate community-acquired pneumonia (CAP).

METHODS

We searched PubMed, Cochrane, and the reference lists of systematic reviews and clinical guidelines. We included randomized trials of adults with radiologically confirmed mild to moderate CAP initially treated orally and reporting clinical cure or mortality. Abstracts and studies were reviewed in parallel for inclusion in the analysis and for data abstraction. We performed separate analyses by antibiotic medications and antibiotic classes and present the results through network diagrams and forest plots sorted by p-scores. We assessed the quality of each study using the Cochrane Risk of Bias framework, as well as global and local inconsistency.

RESULTS

We identified 24 studies with 9361 patients: six at low risk of bias, six at unclear risk, and 12 at high risk. Nemonoxacin, levofloxacin, and telithromycin were most likely to achieve clinical response (p-score 0.79, 0.71, and 0.69 respectively), while penicillin and amoxicillin were least likely to achieve clinical response. Levofloxacin, nemonoxacin, azithromycin, and amoxicillin-clavulanate were most likely to be associated with lower mortality (p-score 0.85, 0.75, 0.74, and 0.68 respectively). By antibiotic class, quinolones and macrolides were most effective for clinical response (0.71 and 0.70 respectively), with amoxicillin-clavulanate plus macrolides and beta-lactams being less effective (p-score 0.11 and 0.22). Quinolones were most likely to be associated with lower mortality (0.63). All confidence intervals were broad and partially overlapping.

CONCLUSION

We observed trends toward a better clinical response and lower mortality for quinolones as empiric antibiotics for CAP, but found no conclusive evidence of any antibiotic being clearly more effective than another. More trials are needed to inform guideline recommendations on the most effective antibiotic regimens for outpatients with mild to moderate CAP.

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.

Compliance with guideline recommendations in the management of patients with hospitalized community-acquired pneumonia

Compliance with guidelines in the empirical treatment for community-acquired pneumonia (CAP) is very important to increase treatment success and reduce mortality. This study aimed to determine compliance with guideline recommendations for CAP and define the role of the clinical pharmacist (CP). Patients diagnosed with CAP were evaluated retrospectively between January 2018 and January 2020 and prospectively between February 2020 and February 2021. Compliance with guidelines was evaluated according to the local, national (Turkish Thoracic Society), and international (American Thoracic Society and Infectious Disease Society of America, European Society of Clinical Microbiology and Infectious Diseases) guidelines. A total of 751 patients (423 in the retrospective and 328 in the prospective period) were included. It was determined that the 30-day mortality and length of stay were higher in patients who were not treated according to the guidelines. The compliance for empirical treatments was 16.3%-59.1% and 7.8%-30.1% in retrospective and prospective periods, respectively. During the prospective period, a total of 603 recommendations were made by CP, and 578 (95.9%) were accepted and implemented. In the prospective period, treatment duration was shortened, inappropriate fluoroquinolone use was decreased, the switch to oral treatment was increased, and the number of potential drug-drug interactions was decreased (p < 0.001). Compliance with guidelines is essential to be improved to reduce mortality, shorten the length of stay, determine the appropriate antimicrobial duration, and reduce the use of fluoroquinolones and broad-spectrum antibiotics unless necessary. CP intervention contributes to the rational selection of antimicrobials, limiting drug-drug interactions, avoiding toxicities, and compliance with guidelines.

Utilization of broad- versus narrow-spectrum antibiotics for the treatment of outpatient community-acquired pneumonia among adults in the United States

PURPOSE

To characterize antibiotic utilization for outpatient community-acquired pneumonia (CAP) in the United States.

METHODS

We conducted a cohort study among adults 18-64 years diagnosed with outpatient CAP and a same-day guideline-recommended oral antibiotic fill in the MarketScan® Commercial Database (2008-2019). We excluded patients coded for chronic lung disease or immunosuppressive disease; recent hospitalization or frequent healthcare exposure (e.g., home wound care, patients with cancer); recent antibiotics; or recent infection. We characterized utilization of broad-spectrum antibiotics (respiratory fluoroquinolone, β-lactam + macrolide, β-lactam + doxycycline) versus narrow-spectrum antibiotics (macrolide, doxycycline) overall and by patient- and provider-level characteristics. Per 2007 IDSA/ATS guidelines, we stratified analyses by otherwise healthy patients and patients with comorbidities (coded for diabetes; chronic heart, liver, or renal disease; etc.).

RESULTS

Among 263 914 otherwise healthy CAP patients, 35% received broad-spectrum antibiotics (not recommended); among 37 161 CAP patients with comorbidities, 44% received broad-spectrum antibiotics (recommended). Ten-day antibiotic treatment durations were the most common for all antibiotic classes except macrolides. From 2008 to 2019, broad-spectrum antibiotic use substantially decreased from 45% to 19% in otherwise healthy patients (average annual percentage change [AAPC], -7.5% [95% CI -9.2%, -5.9%]), and from 55% to 29% in patients with comorbidities (AAPC, -5.8% [95% CI -8.8%, -2.6%]). In subgroup analyses, broad-spectrum antibiotic use varied by age, geographic region, provider specialty, and provider location.

CONCLUSIONS

Real-world use of broad-spectrum antibiotics for outpatient CAP declined over time but remained common, irrespective of comorbidity status. Prolonged duration of therapy was common. Antimicrobial stewardship is needed to aid selection according to comorbidity status and to promote shorter courses.

β-Lactams plus doxycycline versus azithromycin for treatment of severe community-acquired pneumonia in critically ill patients

OBJECTIVES

Community-acquired pneumonia (CAP) is a significant source of hospital admissions and mortality. Atypical organisms are implicated in up to 40% of cases of CAP diagnoses. We studied the difference in outcomes of severe CAP patients treated with doxycycline versus azithromycin in addition to β-lactam therapy.

PATIENTS AND METHODS

This was a prospective observational cohort study from March 2020 to July 2022 in a medical ICU (MICU) of an academic quaternary medical center. Adults ≥18 years admitted to the MICU receiving doxycycline or azithromycin in addition to β-lactam therapy for the treatment of CAP were included for analysis. The primary outcomes were in-hospital and 30 day mortality. Secondary outcomes were ICU and hospital length-of-stay, 30 day readmission, days of mechanical ventilation, escalation and duration of antibiotics, adverse effects such as Clostridioides difficile infection and QTc prolongation.

RESULTS

Sixty-three patients were in the azithromycin group and eighty-six patients in the doxycycline group. Both groups had similar APACHE IV and CURB-65 scores. The mean Charlson Comorbidity Index score was higher for the doxycycline group compared with the azithromycin group (P = 0.04). There was no statistically significant difference in in-hospital and 30 day mortality between the groups (P = 0.53, P = 0.57). There were no significant differences in any of the secondary outcomes.

CONCLUSIONS

MICU patients with severe CAP who received doxycycline versus azithromycin in addition to β-lactam treatment showed no significant differences in outcomes. These data offer support for inclusion of doxycycline as an alternative regimen in current IDSA recommendations.

Diagnostic and Prognostic Roles of Procalcitonin and Other Tools in Community-Acquired Pneumonia: A Narrative Review

Community-acquired pneumonia (CAP) is among the most common causes of death and one of the leading healthcare concerns worldwide. It can evolve into sepsis and septic shock, which have a high mortality rate, especially in critical patients and comorbidities. The definitions of sepsis were revised in the last decade as "life-threatening organ dysfunction caused by a dysregulated host response to infection". Procalcitonin (PCT), C-reactive protein (CRP), and complete blood count, including white blood cells, are among the most commonly analyzed sepsis-specific biomarkers also used in pneumonia in a broad range of studies. It appears to be a reliable diagnostic tool to expedite care of these patients with severe infections in the acute setting. PCT was found to be superior to most other acute phase reactants and indicators, including CRP as a predictor of pneumonia, bacteremia, sepsis, and poor outcome, although conflicting results exist. In addition, PCT use is beneficial to judge timing for the cessation of antibiotic treatment in most severe infectious states. The clinicians should be aware of strengths and weaknesses of known and potential biomarkers in expedient recognition and management of severe infections. This manuscript is intended to present an overview of the definitions, complications, and outcomes of CAP and sepsis in adults, with special regard to PCT and other important markers.

Community-acquired pneumonia - An EFIM guideline critical appraisal adaptation for internists

BACKGROUND

In real-life settings, guidelines frequently cannot be followed since many patients are multimorbid and/or elderly or have other complicating conditions which carry an increased risk of drug-drug interactions. This document aimed to adapt recommendations from existing clinical practice guidelines (CPGs) to assist physicians' decision-making processes concerning specific and complex scenarios related to acute CAP.

METHODS

The process for the adaptation procedure started with the identification of unsolved clinical questions (PICOs) in patients with CAP and continued with critically appraising the updated existing CPGs and choosing the recommendations, which are most applicable to these specific scenarios.

RESULTS

Seventeen CPGs were appraised to address five PICOs. Twenty-seven recommendations were endorsed based on 7 high, 9 moderate, 10 low, and 1 very low-quality evidence. The most valid recommendations applicable to the clinical practice were the following ones: Respiratory virus testing is strongly recommended during periods of increased respiratory virus activity. Assessing the severity with a validated prediction rule to discriminate where to treat the patient is strongly recommended along with reassessing the patient periodically for improvement as expected. In adults with multiple comorbidities, polypharmacy, or advanced age, it is strongly recommended to check for possible drug interactions before starting treatment. Strong graded recommendations exist on antibiotic treatment and its duration. Recommendations on the use of biomarkers such as C-reactive protein or procalcitonin to improve severity assessment are reported.

CONCLUSION

This document provides a simple and reliable updated guide for clinical decision-making in the management of complex patients with multimorbidity and CAP in the real-life setting.