Therapy For Community-acquired Respiratory Tract Infections Research Articles

Antibiotic Susceptibility of Respiratory Pathogens Recently Isolated in Italy: Focus on Cefditoren

The aim of this study was to evaluate the in vitro antibiotic susceptibility of respiratory pathogens recently isolated in italy to commonly used antibiotics including cefditoren. Six clinical microbiological laboratories collected, between January and September 2009, a total of 2,510 respiratory pathogens from subjects with community- acquired respiratory tract infections (CARTI). Cefditoren, out of all the beta-lactams studied, had the lowest MIC90 against 965 strains of Streptococcus pneumoniae examined, followed by cefotaxime and ceftriaxone (2% resistance in penicillin-resistant S. pneumoniae (PRSP)). Against 470 Haemophilus influenzae, independently of their production of beta-lactamases or ampicillin resistance, cefditoren was the oral cephalosporin with the best in vitro activity, comparable to that of the injectable cephalosporins and levofloxacin. Higher MIC90s were found for the macrolides (4 - 16 mg/L) and cefaclor (4 - 32 mg/L). As was foreseeable, Streptococcus pyogenes (225 strains) was uniformly sensitive to all the beta-lactam antibiotics, but the elevated miC90 values reduced (<75%) susceptibility of this pathogen to macrolides. Beta-lactamase-negative Moraxella catarrhalis (100 strains) had reduced susceptibility only to the macrolides, while the 250 beta-lactamase-producing strains also had reduced susceptibility to cefuroxime. Levofloxacin showed the lowest MIC50/MIC90 values in the producing strains, whereas cefditoren, cefotaxime and ceftriaxone in the non-producers. As regards the enterobacteriaceae, cefditoren and levofloxacin had the lowest MIC90s against Klebsiella pneumoniae. Cefditoren and the third-generation injectable cephalosporins had the lowest MIC90s against Escherichia coli (100% susceptibility) while levofloxacin was less active (86% susceptibility).In conclusion, cefditoren's wide spectrum and high intrinsic activity, as well as its capacity to overcome most of the resistance that has become consolidated in some classes of antibiotics widely used as empiric therapy for CARTI, allows us to suggest that cefditoren might be included in the european guidelines as one of the first-choice antibiotics in the treatment of CARTI.

Cethromycin: A Promising New Ketolide Antibiotic for Respiratory Infections

Community-acquired pneumonia remains the primary infectious cause of death in the United States. At current levels of antimicrobial resistance, conventional agents are at risk of becoming less effective, and the need for new agents is pressing. Cethromycin is a new ketolide antibiotic being investigated for use in respiratory tract infections. To review its pharmacology, in vitro susceptibilities, pharmacokinetics, efficacy, safety, and drug interactions, we conducted a MEDLINE search restricted to English-language articles citing cethromycin or ABT-773 (its original designation) from 1990-May 2009. Additional data sources were identified from the references of selected articles. All published trials and available poster data citing cethromycin were selected for review. In vitro, cethromycin displays more potent antibacterial effects than its predecessor telithromycin. Cethromycin exhibits potent inhibition of both gram-positive and gram-negative respiratory pathogens. A new drug application for cethromycin was submitted to the United States Food and Drug Administration in 2008 for the treatment of community-acquired pneumonia. Clinical trial data in the treatment of respiratory tract infections support cethromycin's efficacy. The limited safety data have not included any reports of hepatotoxicity. If cethromycin proves to be safe with regard to hepatotoxicity, it has great promise as an alternative to current standard therapy for community-acquired respiratory infections, especially pneumonia. Given current resistance levels, cethromycin could provide more reliable coverage against common respiratory pathogens than traditional agents in the beta-lactam and macrolide classes.

Selecting Antibiotics for Community-Acquired Respiratory Infections in the Emergency Department

Annually, millions of patients are treated in emergency departments across the country for upper and lower respiratory infections. The purpose of this article was to articulate optimal antibiotic therapy for community-acquired respiratory infections. A table format has been selected to serve as a direct reference for nurse practitioners and physician assistants. In addition, background, common pathogens, and follow-up are discussed for each disease state.

The influence of comorbidity on the effect of levofloxacin treatment success of ambulatory respiratory tract infections.

The influence of patient relevant parameters such as age, comorbidity, or duration of disease on the treatment success of levofloxacin for community-acquired respiratory tract infections (CARTI) has not been thoroughly elucidated. We therefore conducted a prospective cohort study of 9831 patients with CARTI in a clinical practice setting. The patients received 500 mg of levofloxacin once a day over a mean of seven days. Twenty-two attributes per patient were recorded before treatment initiation and after seven to fourteen days after start of treatment. Descriptive and explorative statistics such as the k-means and C4.5 algorithms were used to analyze the dataset. The overall success rate of levofloxacin therapy for CARTI was over 98%, side effects occurred in 1.6% of patients. Descriptive analysis revealed a weak correlation between parameters which significantly influence the course of disease, such as the number of comorbidities, the duration of infection before levofloxacin start, or the severity of symptoms and the treatment success. Explorative statistics yielded similar results. Two homogenous clusters, holding 34 and 45% of patients respectively, yielded the number of comorbid conditions and the duration of infection as main attributes negatively influencing treatment success. We therefore conclude, that the number of co-morbid conditions and the duration of infection before start of treatment as the strongest negative predictors for treatment success.

Doxycycline Activity Against Streptococcus pneumoniae

The choice of empiric antimicrobial therapy for community-acquired respiratory infections is based on pathogens most likely to be encountered. β-Lactam antibiotics are commonly used for both upper and lower respiratory tract infections, and can, in most cases, be used as monotherapy against nonatypical pathogens. Doxycycline, a semisynthetic, second generation tetracycline, has a high degree of activity against all common respiratory pathogens including ampicillin-sensitive-resistant Haemophilus influenzae, β-lactamase-producing strains of Moraxella catarrhalis, and oral pigmented Bacteroides as well as organisms commonly causing atypical pneumonias, eg, Mycoplasma pneumoniae, Legionella pneumophila, or Chlamydia pneumoniae (TWAR agent).