Cost-minimization analysis and audit of antibiotic management of bone and joint infections with ambulatory teicoplanin, in-patient care or outpatient oral linezolid therapy

Bioactive glass: A multifunctional delivery system

Bioactive glasses (BAGs) were invented five decades ago and have been widely used clinically in orthopedic and stomatology. However, in the past two decades, BAGs have been explored immensely by several researchers worldwide as a multifunctional delivery system for a multitude of therapeutics ranging from metal ions to small molecules (e.g., drugs) and macromolecules (e.g., DNA). The impetus for devising a BAG-based delivery system in the 21st century is based upon the facilitative properties it offers for entrapment of a wide range of therapeutic molecules and the tailorable controlled release kinetics to the target tissue site along with the biological activity of the ionic dissolution products in several pathological conditions such as osteoporosis, cancer, infection, and inflammation. This review comprises two parts: the first part discusses the need for a new delivery system and how the journey from melt quench progressed towards template-based sol-gel mesoporous. In the second part, we have comprehended the scientific advancements made so far, emphasizing BAGs as a delivery system ranging from therapeutic ions to phytopharmaceuticals. We have also highlighted a few loopholes that have prevented bench-to-bedside clinical translation of a plethora of elucidative researches done so far.

Evaluation of a thrice weekly administration of teicoplanin in the outpatient setting: a retrospective observational multicentre study

Introduction

The glycopeptide teicoplanin is commonly utilized to facilitate outpatient parenteral antimicrobial therapy (OPAT). Licensed for once daily maintenance dosing, teicoplanin’s long half-life allows for less frequent dosing (e.g. thrice weekly) following successful loading. This service evaluation reviews the safety and effectiveness of a novel thrice weekly teicoplanin dosing regimen.

Methods

A retrospective, observational study was conducted at Chelsea and Westminster Hospital (March 2018 to July 2020), evaluating trough serum teicoplanin concentrations for patients receiving >5 days of teicoplanin in the OPAT setting. Teicoplanin dosing and administration (once daily versus thrice weekly), clinical outcomes and therapeutic levels were analysed for all patients. The project was registered with clinical governance locally.

Results

A total of 82 patients treated with teicoplanin in the OPAT service were included; 53/82 receiving thrice weekly and 29/82 receiving once daily dosing. Mean teicoplanin trough levels were similar in both groups (26.2 mg/L and 25.8 mg/L in once daily and thrice weekly groups, P = 0.8895). High clinical success rates were recorded in both groups (25/29 [86.2%] versus 50/53 [94.3%]). No correlation with clinical outcomes and initial teicoplanin serum levels was identified. Normal renal function (>90 mL/min) was associated with lower teicoplanin serum concentrations (mean [±SD] 21.4 mg/L [±10.1] versus 29.7 mg/L [±14], P = 0.0178) in the thrice weekly dosed group but not with the once daily dosed group (mean [±SD] 28.2 mg/L [±9.4] versus 23.7 mg/L [±9.9], P = 0.2201).

Conclusions

This study supports thrice weekly teicoplanin as a convenient and effective OPAT for administration in the OPAT setting. Therapeutic drug monitoring is advised to adjust for intra-patient variability.

Close Patient Follow-up Among Patients Receiving Outpatient Parenteral Antimicrobial Therapy

BACKGROUND

Outpatient parenteral antimicrobial therapy (OPAT) programs allow patients to receive intravenous treatment in the outpatient setting. We developed a predictive model of 30-day readmission among hospitalized patients discharged on OPAT from 2 academic medical centers with a dedicated OPAT clinic for management.

METHODS

A retrospective medical records review was performed and logistic regression was used to assess OPAT and other outpatient clinic follow-up in conjunction with age, sex, pathogen, diagnosis, discharge medication, planned length of therapy, and Charlson comorbidity score. We hypothesized that at least 1 follow-up visit at the Emory OPAT clinic would reduce the risk for hospital readmission within 30 days.

RESULTS

Among 755 patients, 137 (18%) were readmitted within 30 days. Most patients (73%) received outpatient follow-up care at Emory Healthcare within 30 days of discharge or prior to readmission, including 52% of patients visiting the OPAT clinic. The multivariate logistic regression model indicated that a follow-up OPAT clinic visit was associated with lower readmission compared to those who had no follow-up visit (odds ratio, 0.10 [95% confidence interval, .06-.17]) after adjusting for infection with enterococci, Charlson score, discharge location, and county of residence.

CONCLUSIONS

These results can inform potential interventions to prevent readmissions through OPAT clinic follow-up and to further assess factors associated with successful care transitions from the inpatient to outpatient setting.

Intravenous catheter-related adverse events exceed drug-related adverse events in outpatient parenteral antimicrobial therapy

BACKGROUND

Drug-related adverse events (AEs) are reported to be common amongst patients receiving outpatient parenteral antimicrobial therapy (OPAT). However, comparative data regarding intravenous (iv) catheter-related AEs are lacking.

OBJECTIVES

To compare drug- and iv catheter-related AEs from a large UK OPAT centre.

PATIENTS AND METHODS

We reviewed 544 OPAT episodes [median (IQR) age: 57 (39-71) years, 60% male, 13% with diabetes] with a median (IQR) duration of 7 (2-18) days. Clinically significant drug- and iv catheter-related AEs were calculated as a percentage of OPAT episodes with an AE and also as AEs per 1000 iv drug/catheter days.

RESULTS

Drug-related AEs complicated 13 (2.4%) OPAT episodes at 1.7 (95% CI 0.9-2.9) per 1000 drug days. Catheter-related AEs occurred more frequently, complicating 32 (5.9%) episodes at 5.7 (95% CI 4.2-7.9) per 1000 iv catheter days (χ2 test for difference in AE rate: P < 0.001). Non-radiologically guided midline catheters were associated with the most frequent AEs (n = 23) at 15.6 (95% CI 10.3-23.4) per 1000 iv catheter days compared with other types of iv catheters (HR 8.4, 95% CI 2.4-51.9, P < 0.004), and self-administration was associated with a higher rate of catheter-related AEs at 12.0 (95% CI 6.0-23.9) per 1000 iv catheter days (HR 4.15, 95% CI 1.7-9.1, P = 0.007).

CONCLUSIONS

Clinically significant iv catheter-related AEs occurred more frequently than drug-related AEs, especially when using non-radiologically guided midline catheters. Regular review of the need for iv therapy and switching to oral antimicrobials when appropriate is likely to minimize OPAT-related AEs.

Clinical outcomes of teicoplanin use in the OPAT setting

Teicoplanin possesses several convenient properties for use in the delivery of outpatient parenteral antimicrobial therapy (OPAT) services. However, its use is not widespread and data on its efficacy in the OPAT setting are limited. Here we present a case series of patients undergoing OPAT care being treated by either teicoplanin-based (n = 107) or ceftriaxone-based (n = 191) antibiotic regimens. Clinical failure with teicoplanin occurred in five episodes of care (4.7%) compared with only two episodes of ceftriaxone-based OPAT care (1.0%). Teicoplanin-associated clinical failure was observed in 2 (33.3%) of 6 patients with Enterococcus infections compared with 3 (3.0%) of 101 patients with non-Enterococcus infections. Overall, there were four (2.9%) drug-related adverse events for teicoplanin and four (1.8%) for ceftriaxone, prompting a switch to teicoplanin in three patients. These findings support the continued use of teicoplanin in OPAT as well as its consideration in centres where it is not currently being offered.

Cost-analysis of inpatient and outpatient parenteral antimicrobial therapy in orthopaedics: A systematic literature review

BACKGROUND

Increasing numbers of total joint arthroplasties and consecutive revision surgery are associated with the risk of periprosthetic joint infections (PPJI). Treatment of PPJI is complex and associated with immense socio-economic burden. One treatment aspect is parenteral antiinfective therapy, which usually requires an inpatient setting [Inpatient parenteral antibiotic therapy (IPAT)]. An alternative is outpatient parenteral treatment [Outpatient parenteral antibiotic therapy (OPAT)]. To conduct a health economic cost-benefit analysis of OPAT, a detailed cost analysis of IPAT and OPAT is required. So far, there is a lack of knowledge on the health economic effects of IPAT and OPAT for PPJI.

AIM

To review an economic comparison of IPAT and OPAT.

METHODS

A systematic literature review was performed through Medline following the PRISMA guidelines.

RESULTS

Of 619 identified studies, 174 included information of interest and 21 studies were included for quantitative analysis of OPAT and IPAT costs. Except for one study, all showed relevant cost savings for OPAT compared to IPAT. Costs for IPAT were between 1.10 to 17.34 times higher than those for OPAT.

CONCLUSION

There are only few reports on OPAT for PPJI. Detailed analyses to support economic or clinical guidelines are therefore limited. There is good clinical evidence supporting economic benefits of OPAT, but more high quality studies are needed for PPJI.

Physical and chemical stability of ceftaroline in an elastomeric infusion device

Background

Severe infections such as endocarditis and osteomyelitis require long-term treatment with parenteral antibiotics and hence prolonged hospitalisation. Continuous infusion of ceftaroline through elastomeric devices can facilitate early hospital discharge by managing parenteral antibiotics in patient's home. Therefore, the purpose of this study was to investigate the stability of ceftaroline in a commonly used elastomeric device.

Method

A total of 24 elastomeric devices were prepared, and six elastomeric devices containing 6mg/mL of ceftaroline (three in each type of diluents) were stored at one of the following conditions: 4°C for 6 days, 25°C for 24hours, 30°C for 24hours or 35°C for 24hours. An aliquot was withdrawn before storage and at different time points. Chemical stability was measured using a stability indicating high-performance liquid chromatography, and physical stability was assessed as change in pH, colour and particle content.

Results

Ceftaroline, when admixed with both diluents, was stable for 144, 24 and 12hours at 4°C, 25°C and 30°C, respectively. At 35°C, ceftaroline admixed with normal saline (NS) and glucose 5% was stable for 12hours and for 6hours, respectively. No evidence of particle formation, colour change or pH change was observed throughout the study period.

Conclusions

Our findings support 12 or 24hours continuous elastomeric infusion of ceftaroline-NS admixture, and bulk preparation of elastomeric pumps containing ceftaroline solution in advance. This would facilitate early hospital discharge of patients eligible for the elastomeric-based home therapy and avoid the need for patient's caregivers travelling to the hospital on a daily basis.

Clinical and cost-effectiveness, safety and acceptability of community intravenous antibiotic service models: CIVAS systematic review

OBJECTIVE

Evaluate evidence of the efficacy, safety, acceptability and cost-effectiveness of outpatient parenteral antimicrobial therapy (OPAT) models.

DESIGN

A systematic review.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Library, National Health Service (NHS) Economic Evaluation Database (EED), Research Papers in Economics (RePEc), Tufts Cost-Effectiveness Analysis (CEA) Registry, Health Business Elite, Health Information Management Consortium (HMIC), Web of Science Proceedings, International Pharmaceutical Abstracts, British Society for Antimicrobial Chemotherapy website. Searches were undertaken from 1993 to 2015.

STUDY SELECTION

All studies, except case reports, considering adult patients or practitioners involved in the delivery of OPAT were included. Studies combining outcomes for adults and children or non-intravenous (IV) and IV antibiotic groups were excluded, as were those focused on process of delivery or clinical effectiveness of 1 antibiotic over another. Titles/abstracts were screened by 1 reviewer (20% verified). 2 authors independently screened studies for inclusion.

RESULTS

128 studies involving >60 000 OPAT episodes were included. 22 studies (17%) did not indicate the OPAT model used; only 29 involved a comparator (23%). There was little difference in duration of OPAT treatment compared with inpatient therapy, and overall OPAT appeared to produce superior cure/improvement rates. However, when models were considered individually, outpatient delivery appeared to be less effective, and self-administration and specialist nurse delivery more effective. Drug side effects, deaths and hospital readmissions were similar to those for inpatient treatment, but there were more line-related complications. Patient satisfaction was high, with advantages seen in being able to resume daily activities and having greater freedom and control. However, most professionals perceived challenges in providing OPAT.

CONCLUSIONS

There were no systematic differences related to the impact of OPAT on treatment duration or adverse events. However, evidence of its clinical benefit compared with traditional inpatient treatment is lacking, primarily due to the dearth of good quality comparative studies. There was high patient satisfaction with OPAT use but the few studies considering practitioner acceptability highlighted organisational and logistic barriers to its delivery.

The Community IntraVenous Antibiotic Study (CIVAS): a mixed-methods evaluation of patient preferences for and cost-effectiveness of different service models for delivering outpatient parenteral antimicrobial therapy

Background

Outpatient parenteral antimicrobial therapy (OPAT) is widely used in most developed countries, providing considerable opportunities for improved cost savings. However, it is implemented only partially in the UK, using a variety of service models.

Objectives

The aims of this research were to (1) establish the extent of OPAT service models in England and identify their development; (2) evaluate patients’ preferences for different OPAT service delivery models; (3) assess the cost-effectiveness of different OPAT service delivery models; and (4) convene a consensus panel to consider our evidence and make recommendations.

Methods

This mixed-methods study included seven centres providing OPAT using four main service models: (1) hospital outpatient (HO) attendance; (2) specialist nurse (SN) visiting at home; (3) general nurse (GN) visiting at home; and (4) self-administration (SA) or carer administration. Health-care providers were surveyed and interviewed to explore the implementation of OPAT services in England. OPAT patients were interviewed to determine key service attributes to develop a discrete choice experiment (DCE). This was used to perform a quantitative analysis of their preferences and attitudes. Anonymised OPAT case data were used to model cost-effectiveness with both Markov and simulation modelling methods. An expert panel reviewed the evidence and made recommendations for future service provision and further research.

Results

The systematic review revealed limited robust literature but suggested that HO is least effective and SN is most effective. Qualitative study participants felt that different models of care were suited to different types of patient and they also identified key service attributes. The DCE indicated that type of service was the most important factor, with SN being strongly preferred to HO and SA. Preferences were influenced by attitudes to health care. The results from both Markov and simulation models suggest that a SN model is the optimal service for short treatment courses (up to 7 days). Net monetary benefit (NMB) values for HO, GN and SN services were £2493, £2547 and £2655, respectively. For longer treatment, SA appears to be optimal, although SNs provide slightly higher benefits at increased cost. NMB values for HO, GN, SN and SA services were £8240, £9550, £10,388 and £10,644, respectively. The simulation model provided useful information for planning OPAT services. The expert panel requested more guidance for service providers and commissioners. Overall, they agreed that mixed service models were preferable.

Limitations

Recruitment to the qualitative study was suboptimal in the very elderly and ethnic minorities, so the preferences of patients from these groups might not be represented. The study recruited from Yorkshire, so the findings may not be applicable nationally.

Conclusions

The quantitative preference analysis and economic modelling favoured a SN model, although there are differences between sociodemographic groups. SA provides cost savings for long-term treatment but is not appropriate for all.

Future work

Further research is necessary to replicate our results in other regions and populations and to evaluate mixed service models. The simulation modelling and DCE methods used here may be applicable in other health-care settings.

Funding

The National Institute for Health Research Health Service and Delivery Research programme.

Teicoplanin-based antimicrobial therapy in Staphylococcus aureus bone and joint infection: tolerance, efficacy and experience with subcutaneous administration

Background

Staphylococci represent the first etiologic agents of bone and joint infection (BJI), leading glycopeptides use, especially in case of methicillin-resistance or betalactam intolerance. Teicoplanin may represent an alternative to vancomycin because of its acceptable bone penetration and possible subcutaneous administration.

Methods

Adults receiving teicoplanin for S. aureus BJI were included in a retrospective cohort study investigating intravenous or subcutaneous teicoplanin safety and pharmacokinetics.

Results

Sixty-five S. aureus BJIs (orthopedic device-related infections, 69 %; methicillin-resistance, 17 %) were treated by teicoplanin at the initial dose of 5.7 mg/kg/day (IQR, 4.7–6.5) after a loading dose of 5 injections 12 h apart. The first trough teicoplanin level (C_min) reached the therapeutic target (15 mg/L) in 26 % of patients, only. An overdose (C_min >25 mg/L) was observed in 16 % patients, 50 % of which had chronic renal failure (p = 0.049). Seven adverse events occurred in 6 patients (10 %); no predictive factor could be highlighted. After a 91-week follow-up (IQR, 51–183), 27 treatment failures were observed (42 %), associated with diabetes (OR, 5.1; p = 0.057), systemic inflammatory disease (OR, 5.6; p = 0.043), and abscess (OR, 4.1; p < 10⁻³). A normal CRP-value at 1 month was protective (OR, 0.2; p = 0.029). Subcutaneous administration (n = 14) showed no difference in pharmacokinetics and tolerance compared to the intravenous route.

Conclusions

Teicoplanin constitutes a well-tolerated therapeutic alternative in S. aureus BJI, with a possible subcutaneous administration in outpatients. The loading dose might be increase to 9–12 mg/kg to quickly reach the therapeutic target, but tolerance of such higher doses remains to be evaluated, especially if using the subcutaneous route.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1955-7) contains supplementary material, which is available to authorized users.

Diabetic MRSA foot infection — role of linezolid therapy

Diabetic foot ulceration is common and disabling, often leading to amputation of the leg. Foot ulcers commonly become infected and MRSA infection is becoming more prevalent. MRSA is becoming a major public health problem because of its associated high morbidity and mortality, due to difficulty in its eradication with conventional antibiotics. Although vancomycin is the present mainstay of treatment of MRSA infection, a recently introduced antibiotic, linezolid may have benefits. Linezolid can be given orally, obviating the need for i.v. monitoring and offering potential savings in hospital costs with earlier discharge because of its suitability for out-patient eradication of MRSA.

The dynamic effect on nursing of a changing health service

This paper discusses the dynamic effects on nursing of a changing health service. Scotland's demography presents the profession with unique challenges around securing future services. The Government in Scotland's response has focused on increasing workforce numbers. Workforce dynamics will, however, impact on nursing workforce numbers as all public sector employers compete for a contracting pool of resource. Reserved UK powers for professional regulation and devolved Scottish powers for health and education, matched with specific Scottish laws, can facilitate the development of new roles and new ways of working. Many examples of role development exist and some are provided here.

Adherence to recommendations by infectious disease consultants and its influence on outcomes of intravenous antibiotic-treated hospitalized patients

BACKGROUND

Consultation to infectious diseases specialists (ID), although not always performed by treating physicians, is part of hospital's daily practice. This study analyses adherence by treating physicians to written ID recommendations (inserted in clinical records) and its effect on outcome in hospitalized antibiotic-treated patients in a tertiary hospital in Spain.

METHODS

A prospective, randomized, one-year study was performed. Patients receiving intravenous antimicrobial therapy prescribed by treating physicians for 3 days were identified and randomised to intervention (insertion of written ID recommendations in clinical records) or non-intervention. Appropriateness of empirical treatments (by treating physicians) was classified as adequate, inadequate or unnecessary. In the intervention group, adherence to recommendations was classified as complete, partial or non-adherence.

RESULTS

A total of 1173 patients were included, 602 in the non-intervention and 571 in the intervention group [199 (34.9%) showing complete adherence, 141 (24.7%) partial adherence and 231 (40.5%) non-adherence to recommendations]. In the multivariate analysis for adherence (R2 Cox=0.065, p=0.009), non-adherence was associated with prolonged antibiotic prophylaxis (p=0.004; OR=0.37, 95%CI=0.19-0.72). In the multivariate analysis for clinical failure (R2 Cox=0.126, p<0.001), Charlson index (p<0.001; OR=1.19, 95%CI=1.10-1.28), malnutrition (p=0.006; OR=2.00, 95%CI=1.22-3.26), nosocomial infection (p<0.001; OR=4.12, 95%CI=2.27-7.48) and length of hospitalization (p<0.001; OR=1.01, 95%CI=1.01-1.02) were positively associated with failure, while complete adherence (p=0.001; OR=0.35, 95%CI=0.19-0.64) and adequate initial treatment (p=0.010; OR=0.39, 95%CI=0.19-0.80) were negatively associated.

CONCLUSIONS

Adherence to ID recommendations by treating physicians was associated with favorable outcome, in turn associated with shortened length of hospitalization. This may have important health-economic benefits and stimulates further investigation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN83234896. http://www.controlled-trials.com/isrctn/sample_documentation.asp.

Real time presence of a microbiologist in a multidisciplinary diabetes foot clinic

Multidisciplinary foot-care teams (MDFT) are recommended in the management of severe diabetic foot disease [1]. However, even though infection is often the dominant immediate risk, it is rare to have real time input from a microbiologist. We highlight the value of a microbiologist as a MDFT member.

Spondylodiscitis: update on diagnosis and management

Spondylodiscitis, a term encompassing vertebral osteomyelitis, spondylitis and discitis, is the main manifestation of haematogenous osteomyelitis in patients aged over 50 years. Staphylococcus aureus is the predominant pathogen, accounting for about half of non-tuberculous cases. Diagnosis is difficult and often delayed or missed due to the rarity of the disease and the high frequency of low back pain in the general population. In this review of the published literature, we found no randomized trials on treatment and studies were too heterogeneous to allow comparison. Improvements in surgical and radiological techniques and the discovery of antimicrobial therapy have transformed the outlook for patients with this condition, but morbidity remains significant. Randomized trials are needed to assess optimal treatment duration, route of administration, and the role of combination therapy and newer agents.

National ambulatory emergency care survey: current level of adoption and considerations for the future

Ambulatory emergency care (AEC), ie managing emergency patients without an overnight hospital stay, offers an alternative to routine hospital admission and improved patient experience. The Directory of ambulatory emergency care for adults identifies 49 clinical scenarios which present acutely but could potentially be managed in an ambulatory manner. The Society for Acute Medicine and the NHS Institute for Innovation and Improvement conducted a national survey of 131 UK acute hospitals to understand the current level of AEC provision. Seventy-nine per cent of respondents indicated their site provided some AEC, but the number of conditions covered was limited and AEC tended to be ad hoc and informal at most sites. Weekend access was limited. Only deep vein thrombosis ambulatory protocols were well-established (65%), with other conditions formally implemented as ambulatory pathways at 0-35% of responding sites. There is a significant opportunity for further expansion of AEC through increased awareness and support.

Changes in the classification and management of skin and soft tissue infections

Although skin and soft tissue infections (SSTIs) are extremely common in both primary and secondary care, there is a lack of validated evidence-based schemes for the classification of clinical presentation or severity, and there are few data available on treatment outcomes. The commonly used 'Eron classification' is based on the consensus views of an expert panel, while the Clinical Resource Efficiency Support Team (CREST) 'Guidelines on the Management of Cellulitis in Adults' have not been validated in clinical trials. In the current issue of JAC, investigators at Ninewells Hospital in Dundee, Scotland, report a retrospective study of patients with SSTIs who were treated with antibiotics. The patients were stratified into four classes of clinical severity, based on the presence or absence of sepsis and co-morbidity, and their standardized early warning score. The empirical treatment received by patients in each class was compared with the recommendations of the CREST guidelines. The findings do not make comfortable reading. Overall, 43% of patients (and 65% at the mildest end of the clinical spectrum) were overtreated, while mortality (at 30 days) and inadequate antimicrobial therapy increased with severity class. Strikingly, 35 different empirical antimicrobial prescribing regimens were noted. These findings, which are likely to reflect the situation in many hospitals, show that SSTIs remain a significant cause of mortality and that empirical therapy is bordering on the haphazard, with significant under treatment of severely ill patients.

Emerging drugs for complicated skin and skin-structure infections

IMPORTANCE OF THE FILED: With the worldwide surge of MRSA, skin and skin-structure infection (SSTI) treatment has become a challenge for physicians. Cultures and antibiotic susceptibility tests for SSTIs are the rule due to the implication in morbidity and mortality rates associated with MRSA infections. The need for new antibiotics is evident and the effort to decrease antibiotic resistance is a world priority.

AREAS COVERED IN THIS REVIEW

This manuscript accesses the actual treatments and the developing of antibiotics for MRSA SSTIs.

WHAT THE READER WILL GAIN

This is a review of the data on the available and emerging treatments for MRSA SSTIs.

TAKE HOME MESSAGE

There is an unmet medical need for new antibiotics in the new millennium. As physicians, we must assure all appropriate procedures are completed in order to reduce the bacterial resistance, especially for MRSA.

Maximizing positive outcomes for patients with staphylococcal infections

Maximizing positive outcomes for serious Gram-positive infections, such as those caused by Staphylococcus species, requires an aggressive treatment approach. Although specific approaches will depend upon many factors, the underlying common strategy should recognize the positive contribution of minimizing complications and inpatient treatment duration and the efficient use of healthcare resources, while also focusing on rapid resolution of infection and safety and tolerability. To advance the standard of care for patients, we need to utilize therapies that enable such a range of factors to be improved. Treatment guidelines are useful to establish evidence-based standards of care, but they are updated infrequently and there is currently no pan-European consensus for the treatment of staphylococcal infections. With the benefit of the clinical experience that has been acquired for the most recently licensed antibiotics, together with an appreciation of the appropriate usage of older agents, there are good prospects for achieving positive outcomes earlier and in a greater range of patients with staphylococcal infections, and treatment guidelines should be updated regularly to reflect this.

Health economic issues in the treatment of drug-resistant serious Gram-positive infections

Escalating health care costs have stimulated a paradigm change in the way health care is delivered, reimbursed, and evaluated. Reducing the length of hospital stay and controlling the cost of new technologies and therapies are major factors driving health care decisions. Economic evaluations have had variable success in the decision-making process, partly due to the overall quality, interpretation, and reporting of published analyses. Compared with other Gram-positive pathogens, the economic impact of methicillin-resistant Staphylococcus aureus (MRSA) infections remains the most studied. MRSA infections clearly represent a significant clinical and fiscal burden and future studies analyzing cost-effective strategies that encompass their prevention and optimal management would be beneficial. These studies would need to be carefully designed with clear objectives and explicit perspectives at the onset. Use of an appropriate reference group is key in the design process to measure the true impact of MRSA infections. Health-economic outcome data of the impact of linezolid compared with glycopeptides remain the most robust data available in this therapeutic area.

Clinical efficacy and cost-effectiveness of outpatient parenteral antibiotic therapy (OPAT): a UK perspective

OBJECTIVES

Outpatient parenteral antibiotic therapy (OPAT) is an effective treatment strategy for a wide variety of infections as long as clinical risk is minimized by conforming to practice guidelines. However, its cost-effectiveness has not been established in the setting of the UK National Health Service. We examined the clinical efficacy and cost-effectiveness of an OPAT service based in a large UK teaching hospital, predominantly using the outpatient 'infusion centre' and patient/carer administration models of service delivery.

PATIENTS AND METHODS

Data on clinical activity and outcomes were collected prospectively on 334 episodes of treatment administered by the Sheffield OPAT service between January 2006 and January 2008. Cost-effectiveness was calculated by comparing real costs of OPAT with estimated inpatient costs for these patient episodes incorporating two additional sensitivity analyses.

RESULTS

Of the OPAT episodes, 87% resulted in cure or improvement on completion of intravenous therapy. The readmission rate was 6.3%, and patient satisfaction was high. OPAT cost 41% of equivalent inpatient costs for an Infectious Diseases Unit, 47% of equivalent inpatient costs using national average costs and 61% of inpatient costs using minimum inpatient costs for each diagnosis.

CONCLUSIONS

Using this service model, OPAT is safe and clinically effective, with low rates of complications/readmissions and high levels of patient satisfaction. OPAT is cost-effective when compared with equivalent inpatient care in the UK healthcare setting.

Development of teicoplanin dosage guidelines for patients treated within an outpatient parenteral antibiotic therapy (OPAT) programme

OBJECTIVES

The long elimination half-life of teicoplanin facilitates outpatient parenteral antibiotic therapy (OPAT) with thrice-weekly dosing. This study aimed to develop teicoplanin dosage guidelines for OPAT use from routine clinical data.

METHODS

Patients received 15-25 mg/kg/day for 3 days, then 15-25 mg/kg thrice weekly. Trough concentrations were measured weekly and doses adjusted to maintain 20-30 or 10-20 mg/L according to clinical condition. Concentration-time data were analysed using the pharmacokinetic package NONMEM and the final model was used to develop new dosage guidelines.

RESULTS

Data from 94 and 36 patients were used for model development and validation, respectively. Patient ages ranged from 15 to 94 years, weights from 43 to 146 kg and estimated CL(CR) from 9 to 195 mL/min. Teicoplanin concentrations (n = 670) ranged from 6.7 to 66.9 mg/L and a one-compartment model adequately described the data. The typical estimate of CL was 0.542 L/h and changed by 10.6% for every 10 mL/min difference from a CL(CR) of 66 mL/min. V was 1.62 L/kg. Dosage guidelines based on body weight and CL(CR) can be expected to lead to a significant improvement in the proportion of concentrations in the range 20-30 mg/L. Alternative doses aimed at lower target concentrations have also been developed.

CONCLUSIONS

New dosage guidelines have been developed to support thrice-weekly administration of teicoplanin in an OPAT setting.

Healthcare associated discitis in the era of antimicrobial resistance

Discitis is a recognized and serious complication of healthcare. We describe the cases of 4 patients, who presented to our unit over a 1 year period. All had exposure to healthcare before the onset of discitis and developed complex infections. There were no additional risk factors for discitis in any of the cases. The risk factors for discitis were peripheral intravenous cannulation in 1 case, intraabdominal surgery in 2 cases and multiple risks including intensive care admission and urethral catheterization in another case. The described cases demonstrate the importance of ascertaining a definitive microbiological diagnosis in healthcare associated discitis and the complex and expensive antibiotic regimens that may be required for the management of such cases. Clinicians should be aware when seeing patients with back pain and recent health care exposure that discitis can be present and complicated and that resistant organisms can be the cause.

Pharmacoeconomics of linezolid

BACKGROUND

New antibiotics efficacious in infections caused by resistant Gram-positive microorganisms and with acceptable costs for national health systems per unit of effectiveness are needed.

OBJECTIVE

This paper aimed to summarize all available evidence regarding the pharmacoeconomics of linezolid.

METHODS

A systematic review of pharmacoeconomic analyses through a non-restricted literature search was conducted.

RESULTS/CONCLUSIONS

Linezolid, as compared to vancomycin and teicoplanin, results in a reduction of the necessary resources for the treatment of infections caused by Gram-positive microorganisms. These benefits are attributable to clinical outcomes and to savings associated with the ease of switching from intravenous to oral administration, the shorter duration of intravenous therapy and earlier hospital discharge. Likewise, linezolid, compared to vancomycin and teicoplanin, is a cost-effective treatment.

Delayed development of linezolid resistance in Staphylococcus aureus following exposure to low levels of antimicrobial agents

The development of resistance to linezolid (LZD) in gram-positive bacteria depends on the mutation of a single 23S rRNA gene, followed by homologous recombination and gene conversion of the other alleles. We sought to inhibit this process in Staphylococcus aureus using a range of antibacterial agents, including some that suppress recombination. A model for the rapid selection of LZD resistance was developed which allowed the selection of LZD-resistant mutants with G2576T mutations in all five copies of the 23S rRNA gene following only 5 days of subculture. The emergence of LZD-resistant isolates was delayed by exposing cultures to low concentrations of various classes of antibiotics. All antibiotic classes were effective in delaying the selection of LZD-resistant mutants and, with the exception of fusidic acid (FUS) and rifampin (RIF), prolonged the selection window from 5 to approximately 15 days. Inhibitors of DNA processing were no more effective than any other class of antibiotics at suppressing resistance development. However, the unrelated antimicrobials FUS and RIF were particularly effective at preventing the emergence of LZD resistance, prolonging the selection window from 5 to 25 days. The enhanced suppressive effect of FUS and RIF on the development of LZD resistance was lost in a recA-deficient host, suggesting that these drugs affect recA-dependent recombination. Furthermore, FUS and RIF were shown to be effective inhibitors of homologous recombination of a plasmid into the staphylococcal chromosome. We suggest that RIF or FUS in combination with LZD may have a role in preventing the emergence of LZD resistance.

Daptomycin and tigecycline: a review of clinical efficacy in the antimicrobial era

There is a clinical need for new treatment options as a result of continued increase in the expression of resistance among bacterial pathogens. A number of compounds currently in development show promise. However, in some cases, there is concern that resistance may develop quickly to new compounds that are based on existing antimicrobial agents. Therefore, daptomycin, a novel lipopeptide with a unique mode of action, is of particular interest. It has rapid bactericidal activity against growing and stationary-phase bacteria, once-daily dosing regimen, and has a low potential for the development of resistance. It has been approved for the treatment of complicated skin and soft tissue infections caused by Gram-positive bacteria, and registration for treatment of infective endocarditis and bacteraemia is anticipated. Daptomycin is a welcome addition to the antimicrobial armamentarium for the treatment of bacterial infections. Tigecycline is a new glycyclcycline antimicrobial recently approved for use in the USA, Europe and elsewhere. While related to the tetracyclines, tigecycline overcomes many of the mechanisms responsible for resistance to this class. It is a novel broad spectrum glycylcycline with good activity against Gram-positive, many Gram-negative, anaerobic, and some atypical pathogens that has been developed to address this need. It is efficacious in complicated skin and soft tissue infections and in intra-abdominal infections. This review aims to summarise the key clinical data of daptomycin and tigecycline which hold promise for widespread clinical use in the next decade.

Teicoplanin levels in bone and joint infections: Are standard doses subtherapeutic?

OBJECTIVES

Previously published data suggest that a trough serum teicoplanin level of > or = 20 mg/l is predictive of improved outcomes in serious staphylococcal infection. We investigated how dose regimen and patient characteristics impact on trough teicoplanin levels in patients with musculoskeletal infection, in order to help standardise teicoplanin use.

METHODS

We prospectively collected data for 141 clinically stable adults with bone and joint infection treated as outpatients with teicoplanin. Patients with end stage renal failure were excluded.

RESULTS

The most frequently used teicoplanin dose regimens were 400 mg or 600 mg i.v. once daily. Trough levels were available for 78% of episodes, of which 51% were > or = 20 mg/l. Unsurprisingly, a level of > or = 20 mg/l occurred more often with a dose of 600 mg than with lower doses (p=0.005). There was no significant relationship between teicoplanin level and age, body weight or creatinine clearance, but male gender was associated with lower trough levels than female gender (p=0.03).

CONCLUSIONS

These data suggest that teicoplanin levels of > or = 20 mg/l for bone and joint infection in stable adult patients are best achieved with a daily dose of at least 600 mg.

Linezolid versus Vancomycin for Prosthetic Joint Infections: a Cost Analysis

BACKGROUND

Prosthetic joint infections (PJIs) caused by methicillin-resistant gram-positive bacteria are primarily treated by intravenous vancomycin. Linezolid, active against methicillin-resistant strains and available in oral and intravenous dosage forms, is a potential alternative to vancomycin for the treatment of PJIs.

OBJECTIVE

To analyze the cost of linezolid therapy (outpatient setting) and vancomycin therapy (inpatient and outpatient settings) for PJIs caused by methicillin-resistant gram-positive bacteria.

METHODS

A decision tree was designed to simulate the clinical outcome and healthcare resource utilization of linezolid, vancomycin by outpatient and home parenteral antimicrobial therapies (OHPAT) and vancomycin administered in inpatient setting (rehabilitation facility) for patients with PJIs caused by methicillin-resistant strains. Clinical inputs were estimated from literature and the cost analysis was conducted from the perspective of the public healthcare provider in Hong Kong.

RESULTS

The base-case analysis showed that the vancomycin (OHPAT) group (USD14,470 per patient) was the least costly alternative, followed by the linezolid group (USD17,877 per patient) and the vancomycin (rehabilitation) group (USD19,980 per patient) (1USD = 7.8HKD). The clinical treatment success rates of vancomycin and linezolid were influential factors. Monte Carlo 10,000 simulations showed that the vancomycin (OHPAT) group was less costly than the arms of linezolid and vancomycin (rehabilitation) 64% and 100% of the time, respectively. The linezolid group was less costly than the vancomycin (rehabilitation) group in 65%of the times.

CONCLUSION

Home-infusion of vancomycin therapy appears to be the least costly treatment approach for PJIs caused by methicillin-resistant gram-positive bacteria from the perspective of a Hong Kong public health organization.

Role of linezolid in the treatment of orthopedic infections

Gram-positive organisms, particularly staphylococci and streptococci, are responsible for the majority of bone and joint infections. The rising incidence of antimicrobial resistance among Staphylococcus aureus, coagulase-negative staphylococci and enterococci means that novel antibiotics with unique mechanisms of antimicrobial activity are needed, especially in orthopedic infections. Linezolid is the first of the oxazolidinones, a new class of antibacterial agents particularly effective against Gram-positive infections including methicillin- and vancomycin-resistant strains. With an excellent oral bioavailability and acceptable safety profile, linezolid offers a valuable alternative to more traditional therapies, such as glycopeptides. No large randomized trials have been published on its use in patients with orthopedic infections, but early results are encouraging. Reported adverse events, especially bone marrow suppression and optic neuropathy seen with prolonged administration, mean that treatment of such patients must be undertaken with careful follow-up of laboratory tests. Until now, little resistance has been reported.

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.

Early experience with linezolid for infections in orthopaedics

In infections following orthopaedic surgery, isolated staphylococci are reported to be methicillin resistant (MRSA) in up to 50% of cases. Linezolid, the first in a new class of antibiotics, has excellent efficacy against gram positive organisms that are resistant to other therapies and is 100% orally bioavailable. We report early results of its use for the treatment of resistant infections in orthopaedic practice. Infections were characterised according to the UK Nosocomial Infections National Surveillance Service classification of surgical infections as superficial, deep or organ/space. Osteomyelitis, joint sepsis and deep infection involving orthopaedic implants were included into the final category. Outcome was recorded as clinical, microbiological and blood parameter cure or fail. Over the 12-month study period, 54 patients received linezolid therapy, 41% of these had significant co-morbidity that might affect their ability to fight infection. Sixty-seven percent of infections were in association with implanted metal work. The majority of patients were treated with vancomycin for a short period before linezolid was used as oral 'switch' therapy for longer-term administration, allowing early discharge in all cases. MRSA was isolated in 87% of the patients treated. The mean length of linezolid therapy was 39 days (2-151). Clinical success was achieved in 90% of patients overall. Though there were no life-threatening complications, adverse event rates were significantly higher than those recorded in the literature, with 19% of patients needing to cease therapy. Linezolid offers an alternative to traditional treatments for resistant infections and can facilitate early discharge. Patients need to be monitored closely, particularly where long-term therapy is planned.

A new approach to treatment of resistant gram-positive infections: potential impact of targeted IV to oral switch on length of stay

BACKGROUND

Patients prescribed intravenous (IV) glycopeptides usually remain in hospital until completion of this treatment. Some of these patients could be discharged earlier if a switch to an oral antibiotic was made. This study was designed to identify the percentage of inpatients currently prescribed IV glycopeptides who could be discharged earlier if a switch to an oral agent was used, and to estimate the number of bed days that could be saved. We also aimed to identify the patient group(s) most likely to benefit, and to estimate the number of days of IV therapy that could be prevented in patients who remained in hospital.

METHODS

Patients were included if they were prescribed an IV glycopeptide for 5 days or more. Predetermined IV to oral antibiotic switch criteria and discharge criteria were applied. A multiple logistic regression model was used to identify the characteristics of the patients most likely to be suitable for earlier discharge.

RESULTS

Of 211 patients, 62 (29%) could have had a reduced length of stay if they were treated with a suitable oral antibiotic. This would have saved a total of 649 inpatient days (median 5 per patient; range 1-54). A further 31 patients (15%) could have switched to oral therapy as an inpatient thus avoiding IV line use. The patients most likely to be suitable for early discharge were those with skin and soft tissue infection, under the cardiology, cardiothoracic surgery, orthopaedics, general medical, plastic surgery and vascular specialities, with no high risk comorbidity and less than five other regularly prescribed drugs.

CONCLUSION

The need for glycopeptide therapy has a significant impact on length of stay. Effective targeting of oral antimicrobials could reduce the need for IV access, allow outpatient treatment and thus reduce the length of stay in patients with infections caused by antibiotic resistant gram-positive bacteria.

The safety and efficacy of linezolid in orthopaedic practice for the treatment of infection due to antibiotic-resistant organisms

Linezolid is the first of a new class of antibacterial agents, the oxazolidinones. It is particularly effective against Gram-positive infections and little resistance has been reported, even amongst methicillin- and vancomycin-resistant bacteria. The compound's excellent oral bioavailability and reasonable safety profile, along with the increasing incidence of resistant infections, means that linezolid offers a valuable alternative to more traditional therapies such as vancomycin. Although no large randomised trials have been carried out in patients with orthopaedic infections such as osteomyelitis and septic arthritis, early results are encouraging. However, the apparent increase in observed adverse events, particularly bone marrow suppression, seen with prolonged administration, means that treatment of such patients must be undertaken with careful surveillance, at least until these complications are better understood.

Optimal treatment of infected diabetic foot ulcers

Foot ulceration can lead to devastating consequences in diabetic patients. They are not only associated with increased morbidity but also mortality. Foot infections result as a consequence of foot ulceration, which can occasionally lead to deep tissue infections and osteomyelitis; both of which can result in loss of limb. To prevent amputations prompt diagnosis and treatment is required. Understanding the pathology of the diabetic foot will help in the planning of appropriate investigations and treatment. Clinical diagnosis of infection is based on the presence of discharge from the ulcer, cellulitis, warmth and signs of toxicity; though the latter is uncommon. Deep tissue samples from the ulcer and/or blood cultures should be taken before, but without delaying the start of antibacterial treatment in limb and life-threatening infections. In milder infections wound sampling may direct appropriate antibacterial treatment. Staphylococcus aureus, followed by streptococci are the most common organisms causing infection and antibacterial treatment should be targeted against these organisms in mild infection possibly with monotherapy. But in serious infections combination therapy is required because these are usually caused by multiple organisms including anaerobes. Drug-resistant organisms are becoming more prevalent and methicillin-resistant infections can be treated effectively with a number of oral antibacterials either as monotherapy or in combination. Surgical treatment with debridement, for example, callus removal or drainage of pus form an important part of diabetic foot ulcer management especially in the presence of infection. Occasionally limited surgery including dead infected bone removal may be necessary for resolution of infection. Amputation is sometimes required as a last resort for limb or life preservation.

New therapeutic agents for resistant Gram-positive infections

Gram-positive bacteria are an increasingly common cause of community acquired and nosocomial infections, and their resistance to antibiotics is increasing. The recent reports from several continents of methicillin-resistant Staphylococcus aureus with reduced glycopeptide-susceptibility is of grave concern. New agents are required to meet these threats and several classes of compounds are under development. This review focuses on agents that have been recently licensed or are presently in clinical development for the treatment of serious multidrug-resistant staphylococcal, enterococcal and pneumococcal infections, including methicillin-resistant S. aureus and vancomycin-resistant enterococci.

Antibiotic susceptibility of bacteria most commonly isolated from bone related infections: the role of cephalosporins in antimicrobial therapy

Bone infections, which can be acute or chronic, often require aggressive antibiotic therapy, whether treated at home or in the community. Surveillance programmes are essential tools in the monitoring of antimicrobial resistance and can act as a resource to maintain effective prescribing. The Surveillance Network (TSN), which collects organism and patient-specific data from a network of laboratories across the United States, was used to analyse susceptibility of common bacterial species isolated from bone infections during 2000-2002. Narrow-spectrum antimicrobials such as vancomycin, quinupristin-dalfopristin and linezolid demonstrated good activity against Staphylococcus aureus and streptococci, and were active against 100% of isolates. However, Gram-negative species were also commonly isolated from these sites of infection. Later-generation cephalosporins, represented by ceftriaxone, cefotaxime and cefepime, exhibited a broad spectrum of activity including Enterobacteriaceae, streptococci and methicillin-susceptible S. aureus, but they were not active against methicillin-resistant S. aureus (MRSA) and showed variable activity against Pseudomonas aeruginosa. Using ceftazidime as a marker for extended spectrum beta-lactamase (ESBL) expression, less than 3% of Escherichia coli or Klebsiella pneumoniae expressed this phenotype. Based on current in vitro activity, the third-generation cephalosporins provide broad-spectrum coverage useful for the empirical therapy of suspected bone infections, especially for patients treated in the community or hospitalised with community-acquired infections.