Cost-effective approaches to the treatment of community-acquired pneumonia in the era of resistance

Cost-Effectiveness Of Culture-Based Versus Empirical Antibiotic Treatment For Hospitalized Adults With Community-Acquired Pneumonia In Indonesia: A Real-World Patient-Database Study

OBJECTIVE

This study analyzes the cost-effectiveness of culture-based treatment (CBT) versus empirical treatment (ET) as a guide to antibiotic selection and use in hospitalized patients with community-acquired pneumonia (CAP).

PATIENTS AND METHODS

A model was developed from the individual patient data of adults with CAP hospitalized at an academic hospital in Indonesia between 2014 and 2017 (ICD-10 J.18x). The directed antibiotic was assessed based on microbiological culture results in terms of the impact on hospital costs and life expectancy (LE). We conducted subgroup analyses for implementing CBT and ET in adults under 60 years, elderly patients (≥ 60 years), moderate-severe CAP (PSI class III-V) cases, and ICU patients. The model was designed with a lifetime horizon and adjusted patients' ages to the average LE of the Indonesian population with a 3% discount each for cost and LE. We applied a sensitivity analyses on 1,000 simulation cohorts to examine the economic acceptability of CBT in practice. Willingness to pay (WTP) was defined as 1 or 3 times the Indonesian GDP per capita (US$ 3,570).

RESULTS

CBT would effectively increase the patients' LE and be cost-saving (dominant) as well. The ET group's hospitalization cost had the greatest influence on economic outcomes. Subgroup analyses showed that CBT's dominance remained for Indonesian patients aged under 60 years or older, patients with moderate-severe CAP, and patients in the ICU. Acceptability rates of CBT over ET were 74.9% for 1xWTP and 82.8% for 3xWTP in the base case.

CONCLUSION

Both sputum and blood cultures provide advantages for cost-saving and LE gains for hospitalized patients with CAP. CBT is cost-effective in patients all ages, PSI class III or above patients, and ICU patients.

Influence of pharmacokinetics/pharmacodynamics of antibacterials in their dosing regimen selection

The choice of antimicrobial dosing in clinical practice in the past was based upon a 'penicillin mentality', that is, on the assumption that the in vivo antimicrobial efficacy is dependent on the duration of drug levels above the minimum inhibitory concentration of target microorganisms. Really, a rational antimicrobial therapy is strongly related to a basic understanding of the influence the patient has on the antibiotic (pharmacokinetics [PKs]) and the patient's response to the specific drug effects (pharmacodynamics [PDs]). PK/PD parameters are essential in facilitating the translation of microbiological activity into clinical situations, ensuring a successful outcome. This review will analyze the typical patterns of antimicrobial activity and the corresponding PK/PD parameters, with a special focus on a PK/PD dosing approach with the most commonly utilized antimicrobial agent classes.

Usefulness of triggering receptor expressed on myeloid cells-1 in differentiating between typical and atypical community-acquired pneumonia

OBJECTIVES

The purpose of this study is to investigate the clinical use of inflammatory marker triggering receptor expressed on myeloid cells (TREM)-1 at admission for differentiating between typical and atypical bacterial community-acquired pneumonia (CAP).

METHODS

A prospective, noninterventional study of patients with CAP hospitalized through the emergency department was performed. Surface expression of TREM-1 was analyzed using flow cytometry on peripheral blood cells, and soluble TREM-1 (sTREM-1) concentration was determined in plasma.

RESULTS

Eighty-eight patients with clinical suspicion of CAP were eligible. The causative pathogen was identified in 39 patients (44.3%). After excluding 4 mixed pneumonia cases, 21 typical and 14 atypical bacterial infections were enrolled. Patients with typical bacterial CAP demonstrated increased TREM-1 surface expression on monocytes and neutrophils. Median plasma sTREM-1 levels at admission were 65.2 pg/mL (range, 17.6-138.1 pg/mL) in patients with typical CAP and 25.9 pg/mL (range, 11.5-54.8 pg/mL) in patients with atypical CAP (P < .001). Soluble TREM-1 had good discriminative value to differentiate typical from atypical pathogens with an area under the receiver operating characteristic curve of 0.87 (95% confidence interval, 0.75-0.98). At a cutoff level of 44.2 pg/mL, sTREM-1 yielded a sensitivity of 81%, a specificity of 79%, a positive likelihood ratio of 3.79, and a negative likelihood ratio of 0.24.

CONCLUSIONS

In newly admitted patients with CAP, determination of the TREM-1 levels may provide useful additional diagnostic information on the bacterial etiology.

Evidence for moxifloxacin in community-acquired pneumonia: the impact of pharmaco-economic considerations on guidelines

OBJECTIVE

In an era of limited resources, policy makers and health care payers are concerned about the costs of treatment in addition to its effectiveness. However, guidelines do not tend to consider the cost-effectiveness of treatment options. This paper aims to conduct an international literature review with a view to assessing the impact of pharmaco-economic considerations of CAP treatment with moxifloxacin on recent guidelines.

METHODS

The pharmaco-economic state of the art of treating CAP with moxifloxacin is assessed and compared with guidelines issued by the European Respiratory Society and by the Infectious Diseases Society of America/American Thoracic Society. Also, evidence on moxifloxacin consumption and antimicrobial resistance, and the impact of resistance on the cost-effectiveness of moxifloxacin is reviewed. Studies were identified by searching PubMed, Centre for Reviews and Dissemination databases, Cochrane Database of Systematic Reviews, and EconLit up to January 2009.

RESULTS

The existing pharmaco-economic evidence indicates that moxifloxacin is a cost-effective treatment for CAP. However, data limitations and uncertainty surrounding the evolution of resistance emphasize the need for caution. As recommended by guidelines, the choice of antimicrobial should consider the local frequency of causative pathogens, the local pattern of antimicrobial resistance, and risk factors for resistant bacteria. The pharmaco-economic evidence corroborates the importance of these factors as they have an impact on the cost-effectiveness of treating CAP patients with moxifloxacin.

CONCLUSIONS

CAP guidelines need to take into account pharmaco-economic considerations by balancing the effectiveness of antimicrobial regimens against their costs. The pharmaco-economic value of moxifloxacin is influenced by the causative pathogens involved and resistance patterns. Therefore, it may be advisable to identify patient subgroups in which treatment with moxifloxacin is cost-effective and should be recommended by guidelines.

A pharmacoeconomic review of the management of respiratory tract infections with moxifloxacin

BACKGROUND

Moxifloxacin, a fluoroquinolone, has demonstrated its safety and effectiveness in the management of community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute bacterial sinusitis.

OBJECTIVE

The aim of this article was to provide a synthesis and critical appraisal of economic evaluations of the management of respiratory tract infections with moxifloxacin.

METHODS

Studies were included if they assessed the costs and consequences of moxifloxacin as compared with an alternative antimicrobial in the management of community-acquired pneumonia, acute exacerbations of chronic bronchitis or acute bacterial sinusitis.

RESULTS/CONCLUSIONS

Treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis or acute bacterial sinusitis with moxifloxacin is equally or more effective and less expensive than treatment with other antimicrobials.

Resource utilization of adults admitted to a large urban hospital with community-acquired pneumonia caused by Streptococcus pneumoniae

OBJECTIVE

To determine if penicillin-nonsusceptible Streptococcus pneumoniae, among other variables, was significantly associated with greater hospital costs among patients with community-acquired pneumonia (CAP).

DESIGN

Retrospective, cohort study.

SETTING

Eight hundred ten-bed, urban, private, teaching hospital.

PATIENTS

Adult patients admitted between 1999 and 2003 with CAP caused by S pneumoniae.

INTERVENTION

Clinical criteria and costs (inflated to 2004 dollars) were collected from the medical charts and detailed hospital bills for each individual patient. Costs were compared according to classification by penicillin susceptibility. Multivariate linear regression was utilized to determine variables independently associated with increased hospital costs and length of stay.

RESULTS

Of 168 patients included, 44 patients (26%) had CAP caused by penicillin-nonsusceptible S pneumoniae. Median total hospital costs were 8,654 dollars (25th to 75th percentile, 5,457 dollars to 16,027 dollars), with no difference between susceptible and nonsusceptible groups. Bed costs accounted for 55.6% of total costs, followed by laboratory (9.9%) and pharmacy (9.8%) costs. Regression analyses determined that ICU admission (p < 0.001), unexplained delays in discharge (p = 0.001), and neoplasm (p < 0.04) were independently predictive of both total hospital costs (adjusted r2 = 0.46) and increasing length of stay (adjusted r2 = 0.30). Hospital mortality, bacteremia, and congestive heart failure were also associated with at least one of the dependent variables.

CONCLUSION

In the current era in which more potent antibiotics are empirically utilized to treat CAP, it does not appear that a simple classification of penicillin nonsusceptibility complicates the economic impact of S pneumoniae infection. Focused efforts to reduce length of stay, including minimizing prolonged and unnecessary observation of patients, should have the most profound effect on reducing total costs.

Antibacterial dosing in intensive care: pharmacokinetics, degree of disease and pharmacodynamics of sepsis

Treatment of sepsis remains a significant challenge with persisting high mortality and morbidity. Early and appropriate antibacterial therapy remains an important intervention for such patients. To optimise antibacterial therapy, the clinician must possess knowledge of the pharmacokinetic and pharmacodynamic properties of commonly used antibacterials and how these parameters may be affected by the constellation of pathophysiological changes occurring during sepsis. Sepsis, and the treatment thereof, increases renal preload and, via capillary permeability, leads to 'third-spacing', both resulting in higher antibacterial clearances. Alternatively, sepsis can induce multiple organ dysfunction, including renal and/or hepatic dysfunction, causing a decrease in antibacterial clearance. Aminoglycosides are concentration-dependent antibacterials and they display an increased volume of distribution (V(d)) in sepsis, resulting in decreased peak serum concentrations. Reduced clearance from renal dysfunction would increase the likelihood of toxicity. Individualised dosing using extended interval dosing, which maximises the peak serum drug concentration (C(max))/minimum inhibitory concentration ratio is recommended. Beta-lactams and carbapenems are time-dependent antibacterials. An increase in V(d) and renal clearance will require increased dosing or administration by continuous infusion. If renal impairment occurs a corresponding dose reduction may be required. Vancomycin displays predominantly time-dependent pharmacodynamic properties and probably requires higher than conventionally recommended doses because of an increased V(d) and clearance during sepsis without organ dysfunction. However, optimal dosing regimens remain unresolved. The poor penetration of vancomycin into solid organs may require alternative therapies when sepsis involves solid organs (e.g. lung). Ciprofloxacin displays largely concentration-dependent kill characteristics, but also exerts some time-dependent effects. The V(d) of ciprofloxacin is not altered with fluid shifts or over time, and thus no alterations of standard doses are required unless renal dysfunction occurs. In order to optimise antibacterial regimens in patients with sepsis, the pathophysiological effects of systemic inflammatory response syndrome need consideration, in conjunction with knowledge of the different kill characteristics of the various antibacterial classes. In conclusion, certain antibacterials can have a very high V(d), therefore leading to a low C(max) and if a high peak is needed, then this would lead to underdosing. The V(d) of certain antibacterials, namely aminoglycosides and vancomycin, changes over time, which means dosing may need to be altered over time. Some patients with serum creatinine values within the normal range can have very high drug clearances, thereby producing low serum drug levels and again leading to underdosing.

Clarithromycin extended-release in community-acquired respiratory tract infections

Clarithromycin extended-release (ER) is a second-generation macrolide with bactericidal activity against a broad group of pathogens. It allows for convenient once-daily dosing (2 x 500 mg/day), and has less severe adverse effects than the immediate-release (IR) formulation of the drug, which may result in improved patient compliance. Clarithromycin ER has been approved for the treatment of community-acquired pneumonia, acute maxillary sinusitis and acute bacterial exacerbation of chronic bronchitis. In comparison to the IR formulation, clarithromycin ER demonstrates prolonged absorption from the gastrointestinal tract, allowing for once-daily dosing with improved gastrointestinal tolerability. Various double-blind, randomised clinical trials and group studies have found clarithromycin ER to be an efficacious treatment option, comparable with clarithromycin IR, or its other competitors.

Single-Dose Azithromycin Microspheres vs Clarithromycin Extended Release for the Treatment of Mild-to-Moderate Community-Acquired Pneumonia in Adults

BACKGROUND

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide. The inability or failure of many subjects to adhere to standard antibiotic regimens, which may last up to 10 days, results in suboptimal antibiotic treatment. Treatment with a single-dose antibiotic regimen may improve compliance with prescribed therapy. A novel microsphere formulation of azithromycin provides a single-dose regimen while maintaining tolerability.

STUDY OBJECTIVE

To compare the efficacy and safety of a single 2.0-g dose of azithromycin microspheres to that of an extended-release formulation of clarithromycin (1.0 g/d for 7 days) for the treatment of adults with mild-to-moderate CAP.

DESIGN

A phase III, multinational, multicenter, randomized, double-blind, double-dummy study, comparing single-dose azithromycin microspheres to extended-release clarithromycin, both administered orally.

METHODS

Subjects with mild-to-moderate CAP (Fine class I and II) were included. The primary end point was clinical response at the test-of-cure (TOC) visit (days 14 to 21) in the clinical per protocol (CPP) population. The bacteriologic response at the TOC visit was assessed in subjects with a baseline pathogen.

RESULTS

A total of 501 subjects were randomized, and 499 were treated. Clinical cure rates at the TOC visit in the CPP population were 92.6% (187 of 202 subjects) for azithromycin microspheres and 94.7% (198 of 209 subjects) for extended-release clarithromycin. Overall pathogen eradication rates were 91.8% (123 of 134 subjects) for azithromycin microspheres and 90.5% (153 of 169 subjects) for extended-release clarithromycin. Both agents were well tolerated. The incidence of treatment-related adverse events was 26.3% with azithromycin microspheres and 24.6% with extended-release clarithromycin. Most adverse events were mild to moderate in severity.

CONCLUSION

A single 2.0-g dose of azithromycin microspheres was as effective and well tolerated as a 7-day course of extended-release clarithromycin in the treatment of adults with mild-to-moderate CAP.

Defining the need for new antimicrobials: clinical and economic implications of resistance in the hospitalised patient

Resistance among pathogens causing the most common infections encountered in hospitalised patients is increasing. Due to this resistance, the clinical efficacy of current antimicrobial agents is decreasing against many pathogens, including Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa, extended-spectrum beta-lactamases, and AmpC beta-lactamase-producing organisms. Studies assessing the impact of these resistance mechanisms on clinical outcomes have been performed; however, studies determining the economic impact of resistance have been limited. Strategies to retain the clinical efficacy of currently available agents include the initiation of antimicrobials with efficacy against the suspected pathogen(s) based on data obtained from local antibiograms, the use of combination therapy, and pharmacodynamic optimisation. Once a broad-spectrum regimen has been initiated, de-escalation to narrow, targeted antimicrobial therapy based on susceptibility data is warranted. Despite these efforts, new antimicrobials with novel mechanisms of action are eagerly anticipated to extend the current armamentarium against the growing population of multi-drug-resistant pathogens.

Optimizing antimicrobial pharmacodynamics: dosage strategies for meropenem

INTRODUCTION

Carbapenems are broad-spectrum antibiotics that are often employed as the last line of therapy for patients with nonresponsive nosocomial infections. Consideration of pharmacodynamic principles in dosage regimens for these agents can maximize their antibacterial effectiveness and reduce the number of bacterial strains that survive to mutate or continue infection.

OBJECTIVE

The objectives of this review were to highlight examples of the application of pharmacodynamics to the carbapenems (particularly meropenem) and to comment on clinical utility of these dosage regimens.

METHODS

Relevant information was identified through a MEDLINE search of the literature (1980-present) using the terms carbapenem, pharmacodynamic, pharmacokinetic, pharmacoeconomic, meropenem, imipenem, ertapenem, biapenem, and panipenem. Additionally, meeting posters were identified from the International Conference of Antimicrobial Agents and Chemotherapy (years 2001-2003) and the International Conference of the American Thoracic Society (years 2002-2003). All studies demonstrating the pharmacodynamics of the carbapenems by incorporating changes in dosage strategies were included.

RESULTS

Only relevant data for meropenem were identified in our literature search. The dosage scheme for meropenem may be modified to maximize the percentage of the dosage interval that drug concentrations remain above the minimum inhibitory concentration, an important parameter related to the bacterial kill rate. Only relevant data for meropenem were identified in our literature search. Human volunteer and Monte Carlo simulation studies suggested that in the treatment of susceptible pathogens, higher meropenem doses, increased frequency of administration, or prolonged duration of infusion resulted in improved pharmacodynamics.

CONCLUSION

When proper pharmacodynamic principles are applied to dosage strategies for meropenem, clinical and microbiological outcomes can be optimized.

Efficacy of BAL5788, a prodrug of cephalosporin BAL9141, in a mouse model of acute pneumococcal pneumonia

BAL5788 is a water-soluble prodrug of BAL9141, a new broad-spectrum cephalosporin with high levels of in vitro activity against methicillin- and vancomycin-resistant staphylococci and penicillin-resistant streptococci. In plasma BAL5788 is rapidly converted to BAL9141. We studied the activity of BAL5788 in a mouse model of acute pneumococcal pneumonia. Leukopenic female Swiss albino mice were challenged intratracheally with 10(7) CFU of clinical Streptococcus pneumoniae strains P-52181 (Pen(s) Cro(s) Ctx(s)), P-15986 (Pen(r) Cro(s) Ctx(s)), P-40422 (Pen(r) Cro(r) Ctx(r)), and P-40984 (Pen(r) Cro(r) Ctx(r)). Infected mice received subcutaneous (s.c.) injections of BAL5788 or ceftriaxone starting 3 h after pneumococcal challenge. Uninfected nonleukopenic mice received single s.c. doses of BAL5788 to determine the BAL9141 concentration-time profiles in serum and lungs. Untreated control mice died within 5 days postinfection. Ten-day cumulative survival rates for infected mice receiving BAL5788 (total daily doses of BAL9141 equivalents, 2.1 to 75 mg/kg of body weight) ranged from 57 to 100%, whereas with ceftriaxone (total daily doses, 10 to 400 mg/kg), the survival rates varied between 13 and 100%. In mice infected with P-15986, the survival rates achieved with BAL5788 (BAL9141 equivalent, 8.4 mg/kg) and those achieved with ceftriaxone (50 mg/kg) were significantly different (93 versus 13%; P < 0.0001) in favor of BAL5788; the outcomes of the trials with all other strains were not significantly different between the two antibiotics, but markedly lower doses of BAL5788 than ceftriaxone were required to obtain similar survival rates. Pharmacokinetic data showed that BAL9141 was effective against the four pneumococcal strains tested at very low values of the time above the MIC (T > MIC), which ranged from 9 to 18% of the dosing interval, whereas the values of T > MICs for ceftriaxone ranged from 30 to 50% of the dosing interval.

Use of Monte Carlo simulation to design an optimized pharmacodynamic dosing strategy for meropenem

Prolonging the infusion of meropenem over 3 hours increases the percentage of the dosing interval that drug concentrations remain above the minimum inhibitory concentration (MIC), thereby maximizing the pharmacodynamics of this agent and adhering to drug stability constraints. Monte Carlo simulation was employed to determine pharmacodynamic target attainment rates for several prolonged infusion (PI) meropenem dosage regimens as compared with the traditional 30-minute infusion (TI) against Enterobacteriaceae, Acinetobacter species, and Pseudomonas aeruginosa populations. Percent time above the MIC (%T>MIC) exposures for 1000 mg TI q8h, 2000 mg TI q8h, 500 mg PI q8h, 1000 mg PI q12h, 1000 mg PI q8h, 2000 mg PI q12h, and 2000 mg PI q8h were simulated for 10,000 subjects. Variability in pharmacokinetic parameters and MIC distributions were derived from studies in healthy volunteers and the MYSTIC surveillance program, respectively. The probabilities of attaining bacteriostatic (30% T>MIC) and bactericidal (50% T>MIC) exposures were high for all dosage regimens against populations of Enterobacteriaceae. Against Acinetobacter species and Pseudomonas aeruginosa, the 2000-mg PI q8h dosage regimen provided the highest target attainment rates. For mild to moderate infections caused by Enterobacteriaceae, prolonged infusion regimens of 500 mg PI q8h and 1000 mg PI q12h would provide equivalent target attainment rates to the traditional 30-minute infusion while requiring less drug over 24 hours. For more serious infections presumably caused by Acinetobacter species or Pseudomonas aeruginosa, a dose of 2000 mg PI q8h is recommended because of its high bactericidal target attainment rate against these pathogens. Further study of these dosage recommendations in clinical trials is suggested.