Oral gemifloxacin versus sequential therapy with intravenous ceftriaxone/oral cefuroxime with or without a macrolide in the treatment of patients hospitalized with community-acquired pneumonia: a randomized, open-label, multicenter study of clinical efficacy and tolerability

Oral vs. parenteral antibiotic therapy in adult patients with community-acquired pneumonia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Antibiotic therapy is widely used for patients with community-acquired pneumonia (CAP), and yet whether the efficacy of antibiotics differs based on the treatment mode remains unclear. This study aimed to summarize the evidence regarding the efficacy and safety of oral vs. parenteral administration of antibiotic therapy for the treatment of patients with CAP.

METHODS

The databases of PubMed, EmBase, and the Cochrane Central Register of Controlled Trials were systematically searched for eligible randomized controlled trials (RCTs) from inception until 11 December 2021. The effectiveness of oral vs. parenteral administration of antibiotic therapy was estimated using a random-effects model. Additional sensitivity, subgroup, and publication bias analyses were performed.

RESULTS

Of 912 identified articles, 12 RCTs involving 2158 patients with CAP were included in our pooled analysis. This mostly included trials with low certainty and some concerns regarding risk of bias, including lack of allocation concealment and blinding of participants and personnel. Overall, oral antibiotic therapy did not affect the incidence of clinical success at the end of treatment (relative risk [RR], 1.01; 95% confidence interval [CI], 0.98-1.05; P = 0.417), clinical success at follow-up (RR, 1.02; 95% CI, 0.98-1.06; P = 0.301), or adverse events (RR, 0.87; 95% CI, 0.56-1.35; P = 0.527). Moreover, oral antibiotic therapy had a beneficial effect on the risk of all-cause mortality (RR, 0.58; 95% CI, 0.35-0.96; P = 0.034).

CONCLUSIONS

Oral administration of antibiotics is associated with a reduced risk of all-cause mortality compared with parenteral therapy based on RCTs with low to moderate quality. This finding should be verified in further large-scale RCTs.

Efficacy of Ceftriaxone 1 g daily Versus 2 g daily for The Treatment of Community-Acquired Pneumonia: A Systematic Review with Meta-Analysis

Introduction: Ceftriaxone has been recommended as a first-line treatment for various infections; however, the doses for pneumonia have not been a consensus in randomized clinical trials. To compare ceftriaxone 1 g daily efficacy to other ceftriaxone dosing regimens in community-acquired pneumonia. Area covered: We performed a systematic review and meta-analysis on PubMed, Web of Science, Scopus, and LILACS. Randomized controlled trials of ceftriaxone in community-acquired pneumonia were included. Outcomes included clinical cure in modified intention-to-treatment, clinically and microbiologically evaluable patients. Expert opinion: Ceftriaxone dosages of 1 g daily are as safe and effective as other antibiotic regimens for community-acquired pneumonia. Twenty-four articles fulfilled the inclusion criteria. Twelve studies evaluated ceftriaxone regimens at a dosage of 2 g daily and 12 studies evaluated ceftriaxone at a dosage of 1 g daily. The odds-ratio of clinical cure in the modified intention-to-treatment patients administered either ceftriaxone (4666 patients) or a comparator (4411 patients) was 0.98 (95% CI [0.82-1.17]). Comparator regimens showed similar efficacy to ceftriaxone regimens of 1 g daily, with an odds ratio of 1.03 (95% CI [0.88-1.20]). Dosages higher than ceftriaxone 1 g daily did not result in improved clinical outcomes for community-acquired pneumonia patients (OR 1.02, 95% CI [0.91-1.14]).

Respiratory Fluoroquinolones Monotherapy vs. β-Lactams With or Without Macrolides for Hospitalized Community-Acquired Pneumonia Patients: A Meta-Analysis

Background: The choice of empirical antibiotic treatment for patients with community-acquired pneumonia (CAP) who are admitted to non-intensive care unit (ICU) hospital wards is complicated by the limited availability of evidence. We systematically reviewed the efficacy and safety of strategies of empirical treatment with respiratory fluoroquinolone monotherapy and β-lactam with or without macrolide for non-ICU hospitalized CAP patients. Methods: We searched databases including PubMed, the Cochrane Library (Issue11, 2018), EMbase, China National Knowledge Internet (CNKI), WanFang Data, VIP, and China Biology Medicine disc (CBMdisc) to identify randomized controlled trials (RCTs) involving the comparison of respiratory fluoroquinolone monotherapy and β-lactam with or without macrolide for the non-ICU hospitalized patients with CAP up to November 2018. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed the risk of bias of the included studies. A meta-analysis was performed with the outcomes. Results: A total of 22 studies involving 6,235 patients were included. The results of the meta-analysis showed a non-significant trend toward an advantage to the respiratory fluoroquinolone in overall mortality (RR 0.82, 95% CI 0.65-1.02). No significant difference was found between the two strategies in clinical success (the intention-to-treat population: RR 1.03, 95% CI 0.99-1.08; the clinically evaluable population: RR 1.03, 95% CI 0.999-1.055; the population in which it was unclear whether intention-to-treat or per-protocol analysis was used: RR 1.04, 95% CI 0.99-1.09), microbiological treatment success (RR 1.04, 95% CI 0.997-1.092), and length of stay (SMD -0.06, 95% CI -0.16 to 0.04). The advantage of respiratory fluoroquinolone was statistically significant on the drug-related adverse events (RR 0.87, 95% CI 0.77-0.97). Conclusions: Current evidence shows that fluoroquinolone monotherapy has similar efficacy and favorable safety compared with β-lactam with or without macrolide for non-ICU hospitalized CAP patients. Since the limitation of region, quantity and quality of included studies, more RCTs with large scale and high quality are needed to verify the above conclusion.

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.

The Value of Macrolide-Based Regimens for Community-Acquired Pneumonia

Macrolide antimicrobials are commonly prescribed, specifically for the treatment of respiratory tract infections. Although still effective, the development of widespread macrolide resistance has limited their use. Aside from their antimicrobial effects, macrolides are also known to possess immune-modulatory properties which may confer a survival benefit in both acute and chronic inflammatory states. This review discusses the efficacy, potential mechanisms, and adverse effects of macrolide therapy specifically in community-acquired pneumonia in outpatients, hospitalized ward patients, and those requiring intensive care unit admission. Challenges for ongoing research in this field are discussed and treatment recommendations offered.

Gemifloxacin for the Management of Community-Acquired Respiratory Tract Infections

Community-acquired lower respiratory tract infections (LRTIs) exert a growing clinical and financial burden on healthcare systems and employers. In addition, antimicrobial resistance among pathogens, such as Streptococcus pneumoniae, has compromised the use of commonly prescribed antimicrobial compounds. Newer fluoroquinolones have been developed to meet these emerging demands. Gemifloxacin is a potent, dual-acting fluoroquinolone with excellent activity against S. pneumoniae (MIC(90)0.03-0.06 microg/ml) including those strains demonstrating resistance to other classes of antibiotics. Gemifloxacin demonstrated excellent clinical success in community-acquired lower respiratory infections, has an acceptable safety profile, and is a cost-effective alternative in the management of LRTIs including those caused by resistant pathogens.

Fluoroquinolones in the management of community-acquired pneumonia in primary care

A literature search was conducted to evaluate the pharmacokinetic and pharmacodynamic profile of the respiratory fluoroquinolones (gemifloxacin, levofloxacin and moxifloxacin) and their efficacy and safety in the management of community-acquired pneumonia (CAP). Data show that CAP is a common presentation in primary care practice, and is associated with high rates of morbidity and mortality, particularly in the elderly. Although the causative pathogens differ depending on treatment setting and patient factors, Streptococcus pneumoniae is the primary pathogen in all treatment settings. As a class, the respiratory fluoroquinolones have a very favorable pharmacokinetic and pharmacodynamic profile. Pharmacodynamic criteria suggest that moxifloxacin and gemifloxacin are more potent against S. pneumoniae, which may have the added benefit of reducing resistance selection and enhancing bacterial eradication. The respiratory fluoroquinolones are also generally well tolerated, and are first-line options for outpatient treatment of CAP in patients with comorbidities or previous antibiotic use.

Health economics of use fluoroquinolones to treat patients with community-acquired pneumonia

Respiratory diseases account for approximately 10% of all hospital admissions in the United States. Pneumonia constitutes 35% of these cases, with an average length of stay (LOS) of 5.1 days. It is estimated that $8.4 billion to $10 billion of all annual US hospital expenditures are attributable to community-acquired pneumonia (CAP). As such, medical decisions, including empiric antibiotic choice, potentially exert an impact on hospital LOS and associated costs. In this review, we focus on the empiric antibiotic choices and associated costs of treatment for hospitalized patients with CAP, focusing on the use of fluoroquinolone therapy as recommended by the CAP guidelines.

Fluoroquinolones in the management of community-acquired pneumonia

AIMS

Review of the current guidelines for the use of respiratory fluoroquinolones in the management of community-acquired pneumonia (CAP).

METHODS

Data were collected from recent clinical trials on fluoroquinolone therapy in patients with CAP and from updated recommendations of antimicrobial therapy in managing CAP, with a focus on current North American guidelines.

RESULTS

Randomised clinical trials of respiratory fluoroquinolones (moxifloxacin, levofloxacin and gemifloxacin) in the treatment of CAP were identified and analysed. The bacteriology of CAP, and susceptibility rates, resistance rates and pharmacokinetic and pharmacodynamic properties of fluoroquinolones against causative pathogens in CAP, and adverse event profiles of these agents were described. Respiratory fluoroquinolones have broad-spectrum antibacterial activities against common causative pathogens in CAP and provide an important treatment option as monotherapy for outpatients with comorbidities and inpatients who are not admitted to the intensive care unit (ICU), including those with risk factors of drug-resistant Streptococcus pneumoniae. For treatment of ICU patients with severe CAP, it is recommended that fluoroquinolones be used in combination with a beta-lactam. Recent studies also demonstrated a more rapid resolution of clinical symptoms with the use of highly potent respiratory fluoroquinolones.

DISCUSSION

Appropriate use of fluoroquinolone agents may shorten the duration of antimicrobial therapy and the length of hospital stay and contribute to the decreased development of resistance in patients with CAP. Adverse event profiles of these agents should be considered to facilitate the selection of an appropriate fluoroquinolone for appropriate CAP patients.

CONCLUSION

The fluoroquinolone class, specifically those with adequate activity against respiratory pathogens, represents an important and convenient treatment option for patients with CAP.

Respiratory fluoroquinolones for the treatment of community-acquired pneumonia: a meta-analysis of randomized controlled trials

BACKGROUND

We investigated whether the use of respiratory fluoroquinolones was associated with better clinical outcomes compared with the use of macrolides and beta- lactams among adults with pneumonia.

METHODS

We searched PubMed, Current Contents, Scopus, EMBASE, ClinicalTrials.gov and Cochrane with no language restrictions. Two reviewers independently extracted data from published trials that compared fluoroquinolones (levofloxacin, moxifloxacin, gemifloxacin) with macrolides or beta-lactams or both. A meta-analysis was performed with the clinical outcomes of mortality, treatment success and adverse outcomes.

RESULTS

We included 23 trials in our meta-analysis. There was no difference in mortality among patients who received fluoroquinolones or the comparator antibiotics (OR 0.85, 95% CI 0.65-1.12). Pneumonia resolved in more patients who received fluoroquinolones compared with the comparator antibiotics for the included outcomes in the intention-to-treat population (OR 1.17, 95% CI 1.00-1.36), clinically evaluable population (OR 1.26, 95% CI 1.06-1.50) and the microbiologically assessed population (OR 1.67, 95% CI 1.28-2.20). Fluoroquinolones were more effective than a combination of beta-lactam and macrolide (OR 1.39, 95% CI 1.02-1.90). They were also more effective for patients with severe pneumonia (OR 1.84, 95% CI 1.02-3.29), those who required admission to hospital (OR = 1.30, 95% CI 1.04-1.61) and those who required intravenous therapy (OR = 1.44, 15% CI 1.13-1.85). Fluoroquinolones were more effective than beta-lactam and macrolide in open-label trials (OR = 1.35, 95% CI 1.08-1.69) but not in blinded randomized controlled trials (OR = 1.13, 95% CI 0.85-1.50).

INTERPRETATION

Fluoroquinolones were associated with higher success of treatment for severe forms of pneumonia; however, a benefit in mortality was not evident. A randomized controlled trial that includes patients with severe pneumonia with or without bacteremia is needed.

Gemifloxacin for community-acquired pneumonia

BACKGROUND

Newer fluoroquinolones have become an important therapeutic choice in the treatment of community-acquired pneumonia (CAP). Gemifloxacin is one of the newest members of this class of antibiotics and has performed favourably in this indication.

OBJECTIVE

To analyse the microbiological activity, pharmacokinetic/pharmacodynamic properties and clinical activity of gemifloxacin in CAP, as well as the safety reported in controlled clinical studies.

METHODS

Literature research of English publications in the last 10 years addressing all aspects of gemifloxacin in CAP.

RESULTS/CONCLUSIONS

Gemifloxacin is microbiologically the most active fluoroquinolone against Streptococcus pneumoniae--the leading pathogen of CAP. In several comparative studies gemifloxacin was highly effective and well tolerated in the treatment of mild-to-moderate severe CAP.

The etiology of community-acquired pneumonia in Australia: why penicillin plus doxycycline or a macrolide is the most appropriate therapy

BACKGROUND

Available data on the etiology of community-acquired pneumonia (CAP) in Australia are very limited. Local treatment guidelines promote the use of combination therapy with agents such as penicillin or amoxycillin combined with either doxycycline or a macrolide.

METHODS

The Australian CAP Study (ACAPS) was a prospective, multicenter study of 885 episodes of CAP in which all patients underwent detailed assessment for bacterial and viral pathogens (cultures, urinary antigen testing, serological methods, and polymerase chain reaction). Antibiotic agents and relevant clinical outcomes were recorded.

RESULTS

The etiology was identified in 404 (45.6%) of 885 episodes, with the most frequent causes being Streptococcus pneumoniae (14%), Mycoplasma pneumoniae (9%), and respiratory viruses (15%; influenza, picornavirus, respiratory syncytial virus, parainfluenza virus, and adenovirus). Antibiotic-resistant pathogens were rare: only 5.4% of patients had an infection for which therapy with penicillin plus doxycycline would potentially fail. Concordance with local antibiotic recommendations was high (82.4%), with the most commonly prescribed regimens being a penicillin plus either doxycycline or a macrolide (55.8%) or ceftriaxone plus either doxycycline or a macrolide (36.8%). The 30-day mortality rate was 5.6% (50 of 885 episodes), and mechanical ventilation or vasopressor support were required in 94 episodes (10.6%). Outcomes were not compromised by receipt of narrower-spectrum beta-lactams, and they did not differ on the basis of whether a pathogen was identified.

CONCLUSIONS

The vast majority of patients with CAP can be treated successfully with narrow-spectrum beta-lactam treatment, such as penicillin combined with doxycycline or a macrolide. Greater use of such therapy could potentially reduce the emergence of antibiotic resistance among common bacterial pathogens.

Role of gemifloxacin in the management of community-acquired lower respiratory tract infections

Respiratory tract infections (RTIs) form a substantial clinical and financial burden, with the increasing complication of antimicrobial resistance. This resistance may compromise the use of many empirically prescribed antimicrobials. The new respiratory fluoroquinolones have been developed to overcome this burgeoning resistance. This group includes gemifloxacin, an enhanced-affinity fluoroquinolone that has been approved for clinical use in several countries and is characterised as a potent dual-acting agent with excellent in vitro activity against Streptococcus pneumoniae (minimum inhibitory concentration for 90% of strains (MIC90)=0.03-0.06 microg/mL). Gemifloxacin given once daily for 5-7 days has been shown to be non-inferior to, or in some instances superior to, comparator agents for the treatment of common lower RTIs. Moreover, it is generally well tolerated and is as safe as many frequently empirically prescribed antimicrobials. In addition, studies have shown gemifloxacin to be a cost-effective agent for some lower RTIs.

Cost-effectiveness of oral gemifloxacin versus intravenous ceftriaxone followed by oral cefuroxime with/without a macrolide for the treatment of hospitalized patients with community-acquired pneumonia

We studied the cost-effectiveness of oral gemifloxacin with intravenous ceftriaxone followed by oral cefuroxime with or without a macrolide to treat patients hospitalized with community-acquired pneumonia. Data were prospectively collected as part of a randomized multicenter study. The costs evaluated included antimicrobial acquisition (1st level); plus preparation, dispensing, and administration costs, and treatment of antimicrobial-related adverse events and clinical failures (2nd level); plus per diem costs for hospital stay related to study drug administration (3rd level). At follow-up, clinical success was similar between gemifloxacin (76.9%)- and ceftriaxone (79.1%)-treated patients. The median 1st-level costs for gemifloxacin and ceftriaxone were $136 and $470 (P<0.001), respectively. For the 2nd level, these costs were $158 and $542 (P<0.001), and for the 3rd level, these were $5052 and $5789 (P=0.025), respectively. The median cost per expected success was $6568 for gemifloxacin and $7321 for ceftriaxone (P=0.29). Oral gemifloxacin is clinically effective and has an economic advantage over ceftriaxone, followed by oral cefuroxime with or without a macrolide.

Combination antibiotic therapy improves survival in patients with community-acquired pneumonia and shock*

OBJECTIVE

To assess whether combination antibiotic therapy improves outcome of severe community-acquired pneumonia in the subset of patients with shock.

DESIGN

Secondary analysis of a prospective observational, cohort study.

SETTING

Thirty-three intensive care units (ICUs) in Spain.

PATIENTS

Patients were 529 adults with community-acquired pneumonia requiring ICU admission.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Two hundred and seventy (51%) patients required vasoactive drugs and were categorized as having shock. The effects of combination antibiotic therapy and monotherapy on survival were compared using univariate analysis and a Cox regression model. The adjusted 28-day in-ICU mortality was similar (p = .99) for combination antibiotic therapy and monotherapy in the absence of shock. However, in patients with shock, combination antibiotic therapy was associated with significantly higher adjusted 28-day in-ICU survival (hazard ratio, 1.69; 95% confidence interval, 1.09-2.60; p = .01) in a Cox hazard regression model. Even when monotherapy was appropriate, it achieved a lower 28-day in-ICU survival than an adequate antibiotic combination (hazard ratio, 1.64; 95% confidence interval, 1.01-2.64).

CONCLUSIONS

Combination antibiotic therapy does not seem to increase ICU survival in all patients with severe community-acquired pneumonia. However, in the subset of patients with shock, combination antibiotic therapy improves survival rates.

Pneumonies aiguës communautaires : analyse critique des essais cliniques

Optimal antibiotic treatment of community-acquired pneumonia (CAP) remains controversial. The clinical impact of S. pneumoniae resistance to macrolides is well documented. By contrast high dosage amoxicillin (1 g tid) remains active against such strains and no failure has been reported. The aim of this paper was to review clinical trials in community-acquired pneumonia, published from January 1, 1999, to December 31, 2005. One hundred seventy-three articles were collected, using Medline, 35 of which were analyzed, and 16 finally used. Telithromycin and pristinamycin may be used in mild to moderate CAP. Anti-pneumococcal fluoroquinolones such as levofloxacin and moxifloxacin may be used in at risk patients, but levofloxacin has only been investigated in patients with severe CAP and patients with Legionnaire's disease. Amoxicillin 1 g tid remains the drug of choice for pneumococcal CAP.

Oral antibiotics versus parenteral antibiotics for severe pneumonia in children

BACKGROUND

Acute respiratory infection (ARI) is one of the leading causes of morbidity and mortality in children under five years of age in developing countries. When hospitalisation is required, the usual practice includes administering parenteral antibiotics if a bacterial infection is suspected. This has disadvantages as it causes pain and discomfort to the children, which may lead to treatment refusal or reduced compliance. It is also associated with needle-related complications. In some settings this equipment is in short supply or unavailable necessitating transfer of the child, which increases risks and healthcare costs.

OBJECTIVES

To determine the equivalence in effectiveness and safety of oral antibiotic compared to parenteral antibiotic therapies in the treatment of severe pneumonia in children between three months and five years of age.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2005); MEDLINE (January 1966 to July 2005); EMBASE (January 1990 to July 2005) and LILACS (February 2005).

SELECTION CRITERIA

The review included published or unpublished randomised controlled trials (RCTs) and quasi-RCTs comparing any oral antibiotic therapy with any parenteral antibiotic therapy for the treatment of severe pneumonia in children from three months to five years of age.

DATA COLLECTION AND ANALYSIS

The search yielded more than 1300 titles. Only three studies met all criteria for eligibility. One of the identified trials is yet to publish its results. We did not perform a meta-analysis because of clinical heterogeneity of therapies compared in the included trials.

MAIN RESULTS

Campbell 1988 compared oral co-trimoxazole versus intramuscular procaine penicillin followed by oral ampicillin in 134 children. At the seventh day of follow up, treatment failure occurred in 6/66 (9.1%) in the oral co-trimoxazole group and 7/68 (10.2%) in the combined-treatment group. The risk difference was -0.01% (95% confidence interval (CI) -0.11 to 0.09). The APPIS Group 2004 evaluated 1702 patients comparing oral amoxicillin versus intravenous penicillin for two days followed by oral amoxicillin. After 48 hours, treatment failure occurred in 161/845 (19%) in the amoxicillin group and 167/857 (19%) in the parenteral penicillin group. The risk difference was -0.4% (95% CI -4.2 to 3.3). The authors reported similar recovery in both groups at 5 and 14 days.

AUTHORS' CONCLUSIONS

Oral therapy appears to be an effective and safe alternative to parenteral antibiotics in hospitalised children with severe pneumonia who do not have any serious signs or symptoms.

Optimal pharmacological therapy for community-acquired pneumonia: the role of dual antibacterial therapy

The optimal pharmacological therapy of community-acquired pneumonia (CAP) is one of the most ardently debated issues in medicine. Presently, most guidelines recommend either a fluoroquinolone alone or dual therapy with a third-generation cephalosporin plus a macrolide in patients hospitalised with CAP, but few provide clinicians with specific considerations for selecting from these agents. Despite a similar spectrum of activity and favourable resistance patterns (for fluoroquinolones and third-generation cephalosporins) against CAP pathogens, there is emerging evidence that dual therapy may be superior to monotherapy in certain populations.In patients with non-severe CAP, the evidence supports the use of either monotherapy or dual therapy in most patients; however, patients with severe CAP or bacteraemic pneumococcal CAP experience improved survival when treated with dual therapy. It is unclear from this evidence if any specific combination of agents is the most effective, but the combination of a third-generation cephalosporin plus a macrolide is the most extensively studied. Dual therapy was superior to monotherapy irrespective of the susceptibility of the aetiological pathogen, thus insufficient antimicrobial spectrum does not explain the disparity. The most likely explanation for improved outcomes with dual therapy is the combined effect of optimised antimicrobial spectrum (including atypicals), decreased impact of resistance to a single agent and the immunomodulatory effects of macrolides. Increasing resistance in patients with non-severe CAP warrants the consideration of dual therapy and perhaps a reappraisal of agents usually reserved for second-line therapy, including doxycycline, in these populations as well. In light of the available evidence, dual therapy should be strongly considered in all patients with severe CAP, especially when complicated by pneumococcal bacteraemia.

Highlights on the appropriate use of fluoroquinolones in respiratory tract infections

The impact of respiratory infections on public health is increasing, and lower respiratory tract infections are a major cause of morbidity and mortality. Moreover, most antibiotic prescriptions are related to respiratory infections and this is probably one of the main determinants of the increasing rate of bacterial resistance in both community and hospital settings. This has been the catalyst for the development of new drugs, such as the new fluoroquinolones. The new fluoroquinolones have an excellent spectrum providing cover for the most important respiratory pathogens, including atypical and "typical" pathogens. The pharmacokinetic and dynamic properties of the new fluoroquinolones have a significant impact on their clinical and bacteriological efficacy. They cause a concentration-dependent killing with a sustained post-antibiotic effect. Fluoroquinolones combine exceptional efficacy with cost-effectiveness. Not surprisingly, different guidelines have inserted these agents among the drugs of choice in the empirical therapy of LRTIs. This review discusses the most recent data on the bacteriological and clinical activity of the new fluoroquinolones and critically analyses the risks of a potential overuse of this valuable new class of drugs.

An Approach to Evaluating Drug-Nutrient Interactions

Although the significance of interactions between drugs is widely appreciated, little attention has been given to interactions between drugs and nutrients. Pharmacists are challenged to remember documented interactions involving available drugs, and they face the possibility that each newly approved therapeutic agent may be involved not only in unrecognized drug-drug interactions but in drug-nutrient interactions as well. A more consistent approach to evaluating drug-nutrient interactions is needed. The approach must be systematic in order to assess the influence of nutritional status, food, or specific nutrients on a drug's pharmacokinetics and pharmacodynamics, as well as the influence of a drug on overall nutritional status or on the status of a specific nutrient. We provide such a process, using several recently approved drugs as working examples. Risk factors and clinical relevance are described, with distinctions made between documented and potential interactions. Application of this process by the pharmacist to any drug will help increase their expertise. Furthermore, full consideration by pharmacists of all possible interactions of the drug regimens used in practice can allow for improved patient care.

Antimicrobial activity and a comparison of published pharmacodynamics of gemifloxacin and eight fluoroquinolones against Streptococcus pneumoniae

Gemifloxacin was evaluated for its in vitro activity and was compared with eight fluoroquinolones. Pharmacodynamic comparisons were made based on published pharmacokinetic information. Gemifloxacin demonstrated excellent in vitro activity (minimum inhibitory concentration necessary to inhibit 90% of the strains tested, MIC90 = 0.03 mg/L (range 0.0019-0.03 mg/L)) against 199 strains of Streptococcus pneumoniae. Its activity was not influenced by penicillin or ciprofloxacin non-susceptibility. Gemifloxacin demonstrated excellent pharmacodynamic parameters, with a Cmax/MIC90 of 67 (where Cmax is the peak serum level) and an AUC/MIC90 of 297 (where AUC is the area under the curve). Compared with the other eight fluoroquinolones tested, gemifloxacin demonstrated the best in vitro activity and Cmax/MIC90.

Gemifloxacin for the treatment of respiratory tract infections: in vitro susceptibility, pharmacokinetics and pharmacodynamics, clinical efficacy, and safety

Gemifloxacin is a synthetic fluoroquinolone antimicrobial agent exhibiting potent activity against most gram-negative and gram-positive organisms, such as the important community-acquired respiratory pathogens Streptococcus pneumoniae (including multidrug-resistant S. pneumoniae), Haemophilus influenzae , and Moraxella catarrhalis . The agent's mechanism of action involves dual targeting of two essential bacterial enzymes: DNA gyrase and topoisomerase IV. Gemifloxacin was approved by the Food and Drug Administration in April 2003 for treatment of community-acquired pneumonia and acute bacterial exacerbation of chronic bronchitis. The drug has an oral bioavailability of approximately 71%. Approximately 20-35% of gemifloxacin is excreted unchanged in the urine after 24 hours. The elimination half-life of gemifloxacin is 6-8 hours in patients with normal renal function, supporting once-daily dosing. The 24-hour free-drug area under the plasma concentration-time curve:minimum inhibitory concentration ratio (fAUC(0-24):MIC) associated with efficacy, based on results from in vitro and animal models of infection, is approximately 30. With a mean fAUC(0-24) of approximately 3 microg*hour/ml (35% of total AUC(0-24) of 8.4) and a median S. pneumoniae MIC for 90% of tested strains of 0.03, a fAUC(0-24):MIC ratio of 100 would be expected after standard dosing (320 mg once/day). In clinical studies involving both hospitalized and outpatient populations, gemifloxacin has been highly effective in the treatment of community-acquired pneumonia and acute exacerbation of chronic bronchitis. Clinical success rates ranged from 93.9-95.9% in patients with community-acquired pneumonia and 96.1-97.5% in those with acute exacerbation of chronic bronchitis. Gemifloxacin is well tolerated; the frequency of adverse events with this agent is low. Most adverse events are mild-to-moderate in severity, with diarrhea (< 4%), nausea and rash (< 3%), and headache (< 2%) most commonly reported. Drug interactions with gemifloxacin are not common, although absorption is greatly reduced when given with divalent and trivalent cation-containing compounds, such as antacids. Due to its potent activity against many common gram-positive and gram-negative respiratory pathogens, its proven clinical efficacy, and its favorable safety profile, gemifloxacin is a highly effective empiric treatment for community-acquired lower respiratory tract infections.

The Controversy of Combination vs Monotherapy in the Treatment of Hospitalized Community-Acquired Pneumonia

BACKGROUND

The majority of community-acquired pneumonia (CAP) patients (about 80%) will be treated as outpatients, because therapy with a single agent will work. For the remaining 20% of patients requiring hospitalization, there is some growing debate regarding the efficacy of different management approaches. For hospitalized patients, monotherapy with a respiratory fluoroquinolone agent seems to be gaining popularity, but dual therapy combining a beta-lactam and an advanced macrolide still represents a good choice. Indeed, this regimen was recommended for all of the inpatient categories in the latest Infectious Disease Society of America CAP guidelines in 2003.

AIM

The purpose of this review was to examine the current clinical evidence to support one option or the other by gathering all of the available published literature. We will review the existing controversies in terms of microbiology, immunology, and clinical outcomes comparing dual therapy (ie, with any combination of beta-lactams, macrolides, or fluoroquinolones) with monotherapy in the treatment of CAP.

RESULTS

For the vast majority of patients with CAP (ie, outpatients and inpatients on medical wards), the type of antibiotic regimen prescribed does not have any significant impact. For patients with severe pneumonia, for which there is no accepted definition so far, the controversy remains alive. Mortality from pneumococcal pneumonia has been reduced over the last decades, but despite improved medical care, bacteremic pneumococcal pneumonia is still as lethal as ever, probably because of the aging population, the greater number of immunocompromised patients, and the number of patients with frequent comorbid conditions. Worldwide, the increasing rates of resistance of Streptococcus pneumoniae to antibiotics are also a serious concern, and the clinical implications are not always obvious. Although limited in number, the four studies showing the importance of adding a macrolide to a beta-lactam regimen for the treatment of bacteremic S pneumoniae pneumonia are retrospective and nonblinded, the findings are consistent, and they point to a trend that has to be explored more thoroughly. Studies published in the last few years suggest that combination therapy may be superior for bacteremic S pneumoniae pneumonia.

CONCLUSION

In the meantime, for practical purposes, patients hospitalized with a diagnosis of severe CAP may benefit from a dual antibiotic therapy combining a third-generation cephalosporin and a macrolide. For the majority of hospitalized patients with CAP who are not severely ill, fluoroquinolone monotherapy remains an approved, tested, and reliable option. Indeed, the time for more aggressive outpatient fluoroquinolone therapy may reduce the number of patients who are hospitalized with CAP. Independent prospective studies comparing combination therapy with standard monotherapy are urgently required for hospitalized patients with severe CAP.

Monotherapy versus combination antimicrobial therapy for pneumococcal pneumonia

PURPOSE OF REVIEW

In the past 5 years a number of studies have suggested that combination antibiotic therapy may be superior to monotherapy for pneumococcal pneumonia. This review outlines the major findings for and against combination therapy.

RECENT FINDINGS

The evidence for a benefit of multiple antibiotics is strongest in patients with severe, bacteremic pneumococcal disease. All of these studies have limitations due to their retrospective or uncontrolled design. Unfortunately prospective, randomized, double-blind, controlled studies have not been performed in an appropriately severe disease cohort and are therefore urgently needed. Several viable mechanisms for a benefit of combination therapy have been proposed, especially related to non-antibiotic effects of macrolides. There is also some evidence that third-generation cephalosporins may be superior to penicillins as the non-macrolide component of combination therapy.

SUMMARY

Although based on retrospective and observational data, there is substantial evidence to support combination antibiotic therapy, at least in patients with severe bacteremic pneumococcal pneumonia. What evidence is available supports a cephalosporin/macrolide combination as being associated with the highest survival, but proper prospective studies in patients with severe pneumonia are urgently required to clarify this issue.

Antimicrobial selection for community-acquired lower respiratory tract infections in the 21st century: a review of gemifloxacin

Community-acquired lower respiratory tract infections (LRTIs) are more prevalent in the elderly than in children and younger adults and form a significant proportion of all consultations and hospital admissions in this older age group. Furthermore, in a world of increasing life expectancy the trend seems unlikely to be reversed. Antimicrobial treatment of community-acquired pneumonia (CAP) must cover Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, and in many circumstances should also cover the intracellular (atypical) pathogens. In contrast, acute exacerbations of chronic bronchitis (AECB) are mainly associated with H. influenzae and S. pneumoniae and not with atypical bacteria: in severe cases, other Gram-negative bacteria may be involved. Frequently in LRTIs, the aetiology of the infection cannot be identified from the laboratory specimens and treatment has to be empirical. In such situations it is important to not only to use an antibiotic that covers all likely organisms, but also one that has good activity against these organisms given the local resistance patterns. Gemifloxacin is a new quinolone antibiotic that targets pneumococcal DNA gyrase and topoisomerase IV and is highly active against S. pneumoniae including penicillin-, macrolide- and many ciprofloxacin-resistant strains, as well as H. influenzae and the atypical pathogens. In clinical trials in CAP and AECB, gemifloxacin has been shown to be as effective a range of comparators and demonstrated an adverse event profile that was in line with the comparator agents. In one long-term study in AECB significantly more patients receiving gemifloxacin than clarithromycin remained free of recurrence after 26 weeks. The improved potency, broad spectrum of activity and proven clinical and bacteriological efficacy and safety profile should make it a useful agent in the 21st century battle against community-acquired LRTIs.

Guide to selection of fluoroquinolones in patients with lower respiratory tract infections

Newer fluoroquinolones such as levofloxacin, moxifloxacin, gatifloxacin and gemifloxacin have several attributes that make them excellent choices for the therapy of lower respiratory tract infections. In particular, they have excellent intrinsic activity against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and the atypical respiratory pathogens. Fluoroquinolones may be used as monotherapy to treat high-risk patients with acute exacerbation of chronic bronchitis, and for patients with community-acquired pneumonia requiring hospitalisation, but not admission to intensive care. Overall, the newer fluoroquinolones often achieve clinical cure rates in > or =90% of these patients. However, rates may be lower in hospital-acquired pneumonia, and this infection should be treated on the basis of anticipated organisms and evaluation of risk factors for specific pathogens such as Pseudomonas aeruginosa. In this setting, an antipseudomonal fluoroquinolone may be used in combination with an antipseudomonalbeta-lactam. Concerns are now being raised about the widespread use, and possibly misuse, of fluoroquinolones and the emergence of resistance among S. pneumoniae, Enterobacteriaceae and P. aeruginosa. A number of pharmacokinetic parameters such as the peak concentration of the antibacterial after a dose (C(max)), and the 24-hour area under the concentration-time curve (AUC24) and their relationship to pharmacodynamic parameters such as the minimum inhibitory and the mutant prevention concentrations (MIC and MPC, respectively) have been proposed to predict the effect of fluoroquinolones on bacterial killing and the emergence of resistance. Higher C(max)/MIC or AUC24/MIC and C(max)/MPC or AUC24/MPC ratios, either as a result of dose administration or the susceptibility of the organism, may lead to a better clinical outcome and decrease the emergence of resistance, respectively. Pharmacokinetic profiles that are optimised to target low-level resistant minor subpopulations of bacteria that often exist in infections may help preserve fluoroquinolones as a class. To this end, optimising the AUC24/MPC or C(max)/MPC ratios is important, particularly against S. pneumoniae, in the setting of lower respiratory tract infections. Agents such as moxifloxacin and gemifloxacin with high ratios against this organism are preferred, and agents such as ciprofloxacin with low ratios should be avoided. For agents such as levofloxacin and gatifloxacin, with intermediate ratios against S. pneumoniae, it may be worthwhile considering alternative dose administration strategies, such as using higher dosages, to eradicate low-level resistant variants. This must, of course, be balanced against the potential of toxicity. Innovative approaches to the use of fluoroquinolones are worth testing in further in vitro experiments as well as in clinical trials.

Anti-inflammatory effects of macrolides—an underappreciated benefit in the treatment of community-acquired respiratory tract infections and chronic inflammatory pulmonary conditions?

BACKGROUND

It has been recognized for more than 20 years that the macrolides have immunomodulatory effects that are beneficial for those suffering from chronic pulmonary inflammatory syndromes, such as diffuse panbronchiolitis, cystic fibrosis, asthma and bronchiectasis. The macrolides have consistently been associated with decreased length of stay and mortality when used alone or in combination with beta-lactam antibiotics. This effect can be demonstrated against combinations consisting of beta-lactams and other antibiotics active against 'atypical chest pathogens' when treating community-acquired pneumonia (CAP) in hospitalized patients. As such, it appears that the macrolides' effects in CAP patients are more than just antibacterial in nature. AIMS OF THIS REVIEW: This review aims: to give the reader information on the background areas described, as well as related areas; to review the CAP benefits with macrolides and how they may be related to the immunomodulatory properties they demonstrate, albeit in a shorter period of time than previously demonstrated with chronic pulmonary disorders; to use ex vivo data to support these extrapolations.

LITERATURE SEARCH

A literature search using Medline was conducted from 1966 onwards, searching for articles with relevant key words such as macrolide, diffuse panbronchiolitis, community-acquired pneumonia, biofilm, immunomodulation, cystic fibrosis, erythromycin, clarithromycin, roxithromycin and azithromycin, bronchiectasis and asthma. When appropriate, additional references were found from the bibliographies of identified papers of interest. Any relevant scientific conference proceedings or medical texts were checked when necessary.

CONCLUSIONS

(1) Research into macrolide immunomodulation for chronic pulmonary disorders demonstrates consistent positive effects, although of types other than seen with diffuse panbronchiolitis. These effects, together with their inhibitory activity on biofilms, have the potential to make them a useful option. (2) The benefits for CAP are consistent, and higher when a macrolide is given with another atypical agent than if the other atypical agent is given alone, suggesting a non-antibacterial benefit. (3) Recent research of the immunomodulatory properties of azithromycin imply that azithromycin may have a previously unknown short-term biphasic effect on inflammation modulation: enhancement of host defence mechanisms shortly after initial administration followed by curtailment of local infection/inflammation in the following period. (4) Additional in vivo research is needed prior to developing any firm conclusions.

The newer fluoroquinolones

This article discusses the newer fluoroquinolones in detail with respect to their pharmacokinetics, pharmacodynamics, safety, and spectrum of in vitro activity. The newer agents are compared and contrasted with the older ones, particularly ciprofloxacin. Efficacy of the newer fluoroquinolones when compared with antimicrobial agents in other classes is also presented in detail. Appropriate use of the newer fluoroquinolones is addressed, including their ever expanding role in the treatment of both upper and lower respiratory tract infections and skin and soft tissue infection. Available data on the use of the newer fluoroquinolones in the management of genitourinary tract infections, gastrointestinal infections, and osteomyelitis are also discussed.

Gemifloxacin: a new fluoroquinolone approved for treatment of respiratory infections

OBJECTIVE

To evaluate the microbiology, pharmacokinetic parameters, drug interactions, and results of the available clinical trials of gemifloxacin for the treatment of community-acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis (AECB).

DATA SOURCES

MEDLINE (1966-September 2003) was searched for primary and review articles. Data from the manufacturer were also included. Key words included adverse effects, clinical trials, drug interactions, gemifloxacin, and pharmacokinetic parameters.

STUDY SELECTION AND DATA EXTRACTION

All articles and product labeling concerning gemifloxacin, a fluoroquinolone antibiotic recently approved by the Food and Drug Administration for treatment of CAP and AECB, were included for review.

DATA SYNTHESIS

Compared with currently available fluoroquinolones, gemifloxacin demonstrated improved in vitro activity against Streptococcus pneumoniae (minimum inhibitory concentration for 90% eradication 0.03 microg/mL) and similar activity against gram-negative respiratory pathogens (Haemophilus influenzae, Moraxella catarrhalis) and atypical pathogens such as Chlamydia pneumoniae, Legionella pneumophila, and Mycoplasma pneumoniae. Gemifloxacin, consistent with other available fluoroquinolones, has insufficient activity against methicillin-resistant Staphylococcus aureus to allow clinical use for such infections. Gemifloxacin has adequate bioavailability and a favorable drug interaction profile. Gemifloxacin was comparable to commonly employed nonfluoroquinolone regimens for treatment of CAP and AECB, although the studies were designed to demonstrate equivalence. Gemifloxacin once daily for 5-7 days was well tolerated in controlled and uncontrolled clinical studies. Available clinical data, however, are insufficient to draw clinical or toxicologic distinctions between gemifloxacin and other fluoroquinolones.

CONCLUSIONS

Gemifloxacin may be a suitable choice for empiric treatment of CAP or AECB. However, due to the significant history of fluoroquinolone-induced hepatic failure and dermatologic complications, the use of this drug should be closely monitored.

Monotherapy versus Dual Therapy for Community-Acquired Pneumonia in Hospitalized Patients

Several medical-specialty professional societies have suggested that combination therapy with a beta -lactam plus a macrolide or doxycycline or monotherapy with a "respiratory quinolone" (i.e., levofloxacin, gatifloxacin, moxifloxacin, or gemifloxacin) are optimal first-line therapy for patients hospitalized with community-acquired pneumonia. These recommendations are based predominantly on retrospective studies that suggest improved rates of morbidity and mortality and hospital length of stay among patients treated in such a fashion. Well-designed, prospective, randomized studies confirming this tenet of therapy have not been published, although numerous prospective studies have provided indirect confirmation. The biological rationale for such a differential response (i.e., favoring combination therapy or fluoroquinolone therapy) includes the immunomodulatory effects of macrolides or more-optimal treatment of primary infection or coinfection with atypical pathogens. Well-designed, prospective, randomized trials are required to best define the effectiveness of combination therapy with a beta -lactam plus macrolide or doxycycline or with a respiratory quinolone in hospitalized patients with community-acquired pneumonia.

Efficacy of exclusively oral antibiotic therapy in patients hospitalized with nonsevere community-acquired pneumonia: a retrospective study and meta-analysis

PURPOSE

To assess the efficacy of oral antibiotics in patients hospitalized with community-acquired pneumonia and to identify factors precluding oral therapy.

METHODS

In a meta-analysis, we compared inpatient oral and parenteral therapy in community-acquired pneumonia. Studies were reviewed independently and rated by two reviewers, and results were summarized. We also performed a retrospective cohort study of hospitalized patients with community-acquired pneumonia and compared outcomes in patients treated with oral versus parenteral therapy.

RESULTS

For the meta-analysis, we identified seven studies involving 1366 patients. Study exclusions included severe pneumonia or impaired oral absorption. There was no significant difference in the relative risk of mortality at the end of treatment or at follow-up. Mean length of hospital stay was shorter (6.1 days vs. 7.8 days) in patients taking oral antibiotics than in those taking the parental form. In the retrospective cohort, 18% (124/698) of patients received oral-only therapy; these patients were younger (median age, 75 vs. 78 years, P = 0.01) and had lower mean pneumonia severity index scores (101 vs. 119, P <0.0001) than those who received parenteral therapy. In multivariable models, oral-only patients had a median length of stay that was 1.3 days shorter (95% CI: 0.4% to 2.2% days; P = 0.008) and a median antibiotic cost that was 56 dollars lower (95% CI: 53 dollars to 58 dollars; P <0.0001) than that of patients in the parenteral group, but mortality was similar.

CONCLUSION

Although prospective data are limited, oral antibiotics in certain hospitalized patients with community-acquired pneumonia are effective. More data are needed to identify appropriate candidates for exclusively oral antibiotic therapy.

New Insights in the Treatment by Levofloxacin

Levofloxacin is widely regarded as one of the most important fluoroquinolones available today. It possesses excellent activity against a wide range of important pathogens, including those resistant to many other antimicrobials. While rates of resistance to other previously useful antimicrobial classes has grown, levofloxacin has maintained its efficacy, with generally very low rates of resistance around the world. It is indicated for a wide range of infections including community-acquired respiratory infections in adults, particularly community-acquired pneumonia (CAP), acute bacterial exacerbations of chronic bronchitis (AECB), and acute sinusitis. In addition, it is recommended for infections of skin and soft tissue, and the urinary tract. With postmarketing surveillance data available for the last decade, levofloxacin possesses an unparalleled database to demonstrate its clinical efficacy and safety. Remarkably, levofloxacin continues to expand its list of indications. The development of a new high-dose 750-mg schedule has the potential to decrease the duration of treatment as well as reduce the emergence of resistance.

Gemifloxacin Mesylate

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