Comparative pharmacoeconomic study of vancomycin and teicoplanin in intensive care patients

Antimicrobial stewardship program at a tertiary care academic medical hospital: Clinical, microbiological and economic impact. A 5-year temporary descriptive study

Introduction

Few prospective studies analyze, with sufficient duration, the impact of an antimicrobial stewardship program (AMSP) carried out entirely in a hospital.

Methods

Descriptive study evaluating the consumption of antimicrobials expressed in defined daily doses (DDD) per 100 hospital occupied bed-days (OBDs) stratified in medical, surgical and intensive care unit (ICU) and the incidence of densities (ID) per 1,000 hospital OBDs of the prevalent multidrug-resistant organisms (MDRO) in a tertiary hospital, over a period of 5 years before and after the implementation of an AMSP. Analysis of direct costs and those associated with hospital stay and mortality.

Results

A total of 32,802 patients with antibiotic treatment were included in the intervention period (2013–2017). Non-imposed advice was exercised in 14.9%. The degree of adherence to recommendation was 87.9%, direct treatment and de-escalation being the most frequently admitted interventions (P<0.001). Overall hospital consumption of antibacterials in DDD/100s decreased by 5.7% (77.04 vs. 71.33) between 2008 and 2017. In ICU, the average DDD/100s showed a reduction from 155 to 113 (mean difference -18, P=0.005). There was a decrease in the DI/1000 OBDs of MDROs in the post-intervention period (RR 0.78; CI 95% [0.73, 0.84], P<0.001). The average annual cost of antibacterials declined from €1,435,048 to €955,805 (mean difference -€469,243; P=0.001).

Conclusion

Long-term maintenance of a hospital AMSP was associated with a reduction in antibiotic consumption, especially in ICU, as well as a beneficial ecological impact and economic savings.

Management of adult Clostridium difficile digestive contaminations: a literature review

Clostridium difficile infections (CDI) dramatically increased during the last decade and cause a major public health problem. Current treatments are limited by the high disease recurrence rate, severity of clinical forms, disruption of the gut microbiota, and colonization by vancomycin-resistant enterococci (VRE). In this review, we resumed current treatment options from official recommendation to promising alternatives available in the management of adult CDI, with regard to severity and recurring or non-recurring character of the infection. Vancomycin remains the first-line antibiotic in the management of mild to severe CDI. The use of metronidazole is discussed following the latest US recommendations that replaced it by fidaxomicin as first-line treatment of an initial episode of non-severe CDI. Fidaxomicin, the most recent antibiotic approved for CDI in adults, has several advantages compared to vancomycin and metronidazole, but its efficacy seems limited in cases of multiple recurrences. Innovative therapies such as fecal microbiota transplantation (FMT) and antitoxin antibodies were developed to limit the occurrence of recurrence of CDI. Research is therefore very active, and new antibiotics are being studied as surotomycin, cadazolid, and rinidazole.

Cost-Effectiveness Analysis of the Treatment of Ventilator-Associated Pneumonia with Linezolid or Vancomycin in Spain

The aim of this study was to assess the cost-effectiveness of linezolid (LIN) versus vancomycin (VAN) for the treatment of ventilator-associated pneumonia (VAP) using a decision model analysis from the National Health System perspective. Patients and participants comprising four subgroups were analyzed: all, Gram-positive (GP), Staphylococcus aureus (SA), methicillin-resistant SA (MRSA). The treatments were LIN 600 mg i.v., every 12 hours, 10 days and VAN 1,000 mg i.v., every 12 hours 10 days. The primary outcome was the incremental cost-effectiveness of LIN in terms of cost per added quality-adjusted life year (QALY) gained. The secondary outcome was the marginal cost per year of life saved (LYS) generated by using LIN. Clinical cure and survival rates estimates were derived from a retrospective analysis of two trials comparing LIN with VAN. QALY was based on time-trade off study. Resource use and unit costs (Euros 2003) were obtained from Spanish VAP treatment and health cost databases. The additional QALY and LYS per LIN patients were 0.392; 0.688; 0.606; 1.805 and 0.471; 0.829; 0.729; 2.175 respectively, compared with those of VAN in the patients with VAP (all, GP, SA, and MRSA, respectively). The additional costs for LYS with LIN, as compared to VAN were 1,501.31; 827.63; 955.13 and 289.51 Euros, respectively. The additional cost per QALY with LIN was 1,803.87; 997.25; 1,149.00 and 348.85 Euros, respectively.

CONCLUSIONS

LIN was more cost-effective than VAN in the treatment of VAP in Spain, with an additional cost per QALY/LYS gained below the acceptable threshold in Spain of Euros 30,000 for new therapies.

Measurement of teicoplanin by liquid chromatography-tandem mass spectrometry: development of a novel method

BACKGROUND

Teicoplanin is an antibiotic used for the treatment of endocarditis, osteomyelitis, septic arthritis and methicillin-resistant Staphylococcus aureus. Teicoplanin is emerging as a suitable alternative antibiotic to vancomycin, where their trough serum levels are monitored by immunoassay routinely. This is the first report detailing the development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring teicoplanin in patients' serum.

METHODS

An Acquity™ UPLC (ultra-pressure liquid chromatography) tandem mass spectrometer was used to measure teicoplanin concentrations in samples from patients, quality assurance schemes and quality control preparations. Ristocetin was successfully implemented as a suitable internal standard. Ion suppression, linearity, stability, matrix effects, recovery, imprecision, lower limits of quantification and detection, interference and method comparison against immunoassay were all assessed.

RESULTS

Teicoplanin and ristocetin had elution times of 1.39 and 1.24 min, respectively. Ion suppression was shown to be negligible, and linear calibration curves (0-200 μg/mL) were consistently reproduced to have r(2) values >0.99. Postextraction stability was achieved up to 20 h, while matrix effects were minimal coupled with sample recovery of >93%. The lower limit of quantification was 1 μg/mL, and 0.2 μg/mL was the lower limit of detection. Interference with other antibiotics was dependent on the combination of drugs present in patients' serum. A method comparison between immunoassay and LC-MS/MS suggested a negative bias for tandem mass spectrometry.

CONCLUSIONS

This novel method of teicoplanin determination by LC-MS/MS is proven to be a robust protocol that is consistent and reproducible. Clinicians searching for alternatives in therapeutic drug monitoring may have an additional option that is potentially more accurate and specific.

Teicoplanin versus vancomycin for proven or suspected infection

BACKGROUND

Vancomycin and teicoplanin are commonly used to treat gram-positive infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). There is uncertainty regarding the effects of teicoplanin compared to vancomycin on kidney function with some previous studies suggesting teicoplanin is less nephrotoxic than vancomycin.

OBJECTIVES

To investigate the efficacy and safety of vancomycin versus teicoplanin in patients with proven or suspected infection.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles with relevant studies and sent letters seeking information about unpublished or incomplete studies to investigators involved in previous studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in any language comparing teicoplanin to vancomycin for patients with proven or suspected infection.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated methodological quality and extracted data using standardised data extraction forms. Study investigators were contacted for information not available in the original manuscripts. Random effects model was used to estimate the pooled risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 24 studies (2,610 patients) in this review. Teicoplanin reduced the risk of nephrotoxicity compared to vancomycin (RR 0.66, 95% CI 0.48 to 0.90).The effects of teicoplanin or vancomycin were similar for clinical cure (RR 1.03, 95% CI 0.98 to 1.08), microbiological cure (RR 0.98, 95% CI 0.93 to 1.03) and mortality (RR 1.02, 95% CI 0.79 to1.30). Six studies reported no cases of acute kidney injury (AKI) needing dialysis. Adverse events were less frequent with teicoplanin including cutaneous rash (RR 0.57, 95% CI 0.35 to 0.92), red man syndrome (RR 0.21, 95% CI 0.08 to 0.59) and total adverse events (RR 0.73, 95% CI 0.53 to 1.00). A lower risk of nephrotoxicity with teicoplanin was observed in patients either with (RR 0.51, 95% CI 0.30 to 0.88) or without aminoglycosides (RR 0.31, 95% 0.07 to 1.50), and also when vancomycin dosing was guided by serum levels (RR 0.22, 95% CI 0.10 to 0.52).

AUTHORS' CONCLUSIONS

Teicoplanin and vancomycin are both effective in treating those with proven or suspected infection; however the incidence of adverse effects including nephrotoxicity was lower with teicoplanin. There were no cases of AKI needing dialysis. It remains unclear whether the differential effect on kidney function should influence which antibiotic be prescribed, although it may be reasonable to consider teicoplanin for patients at higher risk for AKI needing dialysis.

Transferability indices for health economic evaluations: methods and applications

In this paper, we have elaborated an index in two phases to measure the degree of transferability of the results of the economic evaluation of health technologies. In the first phase, we have considered the objective factors (critical and non-critical) to derive a general transferability index, which can be used to measure this internal property of the studies of economic evaluation applied to health technologies. In the second phase, with a more specific index, we have measured the degree of applicability of the results of a given study to a different setting. Both indices have been combined (arithmetic and geometric mean) to obtain a global transferability index. We have applied the global index to a sample of 27 Spanish studies on infectious diseases. We have obtained an average value for the index of 0.54, quite far from the maximum theoretical value of 1. We also found that 11 studies lacked some critical factor and were directly deemed as not transferable.

Predictors of efficacy and health resource utilization in treatment of complicated intra-abdominal infections: evidence for pooled clinical studies comparing tigecycline with imipenem-cilastatin

BACKGROUND

Duration of intravenous (IV) treatment, surgical/radiologic interventions for infection control, and hospital length of stay (LOS) are important cost considerations in complicated intra-abdominal infections (cIAIs).

METHODS

Data were pooled from two multinational, double-blind studies conducted in hospitalized adults with cIAIs who were randomized (1:1) to receive tigecycline (100 mg IV initial dose then 50 mg IV every 12 h) or imipenem-cilastatin (500 mg IV every 6 h) for 5 to 14 days in order to assess tigecycline safety and efficacy. This report focuses on developing predictors of cure and health care resource utilization, including the need for repeat surgical/radiologic interventions, duration of IV antibiotic therapy, and hospital LOS. Multiple regression models were applied for each of the above outcomes, incorporating both baseline and on-treatment potential covariates. Logistic modeling was used for categorical outcomes (cure; repeat surgical/radiologic interventions) and least squares modeling for continuous outcomes (duration of IV antibiotic therapy; LOS). Stepwise selection was used to retain only those predictors found to be significant (p < 0.05) independent risk factors.

RESULTS

The most common causative pathogen was Escherichia coli (63.0%), with 63.3% of the patients exhibiting polymicrobial infections. The most common cIAI diagnosis was complicated appendicitis (51.9%). Lack of clinical cure (+ 6.1 days; p < 0.0001), perforation of the intestine (+3.7 days; p < 0.0001), an Acute Physiology and Chronic Health Evaluation (APACHE) score >15 (+3.1 days; p=0.039), abnormal plasma sodium concentration (+3.7 days; p=0.026), and repeat surgical/radiologic intervention (+2.2 days; p=0.0097) were identified as key risk factors for longer LOS. Inadequate source control was associated with reduced odds of cure, longer IV treatment duration (+1.5 days; p=0.007), and longer LOS. The treatment groups did not differ in terms of LOS, IV treatment duration, or clinical cure.

CONCLUSION

Tigecycline was similar to imipenem-cilastatin in terms of both efficacy and health resource utilization. Risk factors identified in this study for both outcome measures are offered as support for guiding clinical practice.

Epidemiology and economic impact of meticillin-resistant Staphylococcus aureus: review and analysis of the literature

In the past 2 decades, meticillin-resistant Staphylococcus aureus (MRSA) has become an increasingly prevalent problem in healthcare, both in acute care institutions and in the community. MRSA is associated with worse outcomes and higher costs for care than meticillin sensitive S. aureus (MSSA). MRSA is a particular problem in several conditions, including hospital-acquired pneumonia (including ventilator-associated pneumonia), skin and soft tissue infections, and diabetic foot infections. Hospitalisation costs associated with MRSA infection are substantially greater than those associated with MSSA infection, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In several countries, infection control programmes have shown potential economic benefits, as savings accruing from strict and effective control have been shown to outweigh the cost of policy implementation. Standard therapy is based on glycopeptide treatment, usually with vancomycin, although resistance to this agent has emerged. Alternative available treatments for MRSA include teicoplanin, tigecycline, daptomycin, quinupristin-dalfopristin and the oxazolidinone, linezolid, which has a higher acquisition cost than vancomycin but is available as intravenous and oral formulations. Despite some limitations of analyses to date, linezolid has been shown to be cost effective in the treatment of MRSA and appears to be related, in part, to the drug's potential for facilitating earlier discharge from hospital. Current opinion favours rational prescribing to maximise therapeutic benefit and minimise the risk of further antibacterial resistance.

Economic evaluation in critical care medicine

Scarce resources are a reality in all health care systems. There is a constant challenge to maximize health benefits within the resources available. This is particularly relevant when caring for critically ill patients, given the resource-intensive technologies and medicines used and the highly specialized professionals required. Moreover, given the high acuity of illness, decision makers and health care providers in critical care units must constantly assess the value derived from therapies and resources used. Economic evaluation is the comparative analysis of alternative health care interventions in their relative costs (resource use) and effectiveness (health effects). Economic evaluations have been increasingly published in critical care journals and read by clinicians. This article illustrates how the basic principles of health economics can be applied to health care decision making through the use of economic evaluation. We demonstrate how economic evaluation can link medical outcomes, quality of life, and costs in a common index, even for therapies for different medical conditions and with different health outcomes. This article highlights the need for randomized clinical trials and economic evaluations of therapies in critical care medicine for which the effect of the therapy on health outcomes and/or costs are unknown.

Gram-positive cocci infections in intensive care: guide to antibacterial selection

The incidence of multiresistance in Gram-positive cocci causing infections in critically ill patients admitted to the intensive care unit (ICU) has increased notably in recent years. Thus, therapeutic proposals have been modified according to the emergence of multiresistant cocci and adapted to epidemiological markers of individual infectious processes, geographical variations of these markers, the availability of new antibacterials, and advances in the knowledge of pharmacokinetic and pharmacodynamic aspects of their use. The current management of critically ill patients should consider new therapeutic approaches, such as the "de-escalating strategy", which includes the administration of empirical antibacterials active against multiresistant pathogens followed by directed treatment based on unequivocal data from antibacterial-susceptibility testing. Optimisation of antibacterial treatment should be viewed in the context of the need to determine plasma drug concentrations, pharmacoeconomic considerations and control of drug-related adverse events. Therapeutic proposals should be developed within the framework of the antibacterial policy of each hospital. The present review is focused on the description of the therapeutic strategies for the main infectious processes caused by Gram-positive cocci in severely ill patients admitted to the ICU according to a review of the pertinent literature and the clinical experience of the authors.

Direct medical costs associated with using vancomycin in methicillin-resistant Staphylococcus aureus infections: an economic model

OBJECTIVES

To quantify the direct medical costs associated with using vancomycin, as inpatient treatment, in methicillin-resistant Staphylococcus aureus infections, in four clinical indications: complicated skin and soft tissue infections (SSTI), bacteremia, infective endocarditis (IE), and hospital-acquired pneumonia (HAP).

RESEARCH DESIGN AND METHODS

A decision-analytic model was constructed to evaluate the cost of administering intravenous vancomycin. Cost inputs included hospitalization, drug procurement, materials, preparation and administration, renal function and drug monitoring, treating adverse events, and treatment failure. Probabilities and lengths of stay and treatment were obtained from the literature, an antimicrobial therapy database and clinical expert opinion. Univariate and multivariate sensitivity analyses were conducted to confirm the robustness of the baseline scenario.

MAIN OUTCOME MEASURES

The cost of using vancomycin in the four indications, including and excluding hospital cost.

RESULTS

Whereas the drug acquisition price of vancomycin 1g is US dollars 9.01 per dose, when all costs associated with using vancomycin were included, the cost per dose rose to US dollars 29-US dollars 43 per patient. Total costs per patient receiving multiple doses in a single course of treatment, excluding hospital room costs, were for SSTI, bacteremia, IE, and HAP,US dollars 779, US dollars 749, US dollars 2261, and US dollars 768, respectively. Total costs, including hospital length of stay, were for SSTI US dollars 23616, bacteremia US dollars 26446, IE US dollars 48925, and HAP US dollars 22493. In univariate analyses varying per diem hospital costs and length of stay had the greatest impact. Results of the multivariate analysis were comparable to the costs in the baseline scenario for all indications.

CONCLUSIONS

This analysis highlights the importance of capturing all costs associated with using a drug and not simply focusing on drug acquisition cost. Future economic analyses should identify and account for the key cost burdens of a particular treatment to calculate its true cost.