Antimicrobial consumption in an acute NHS Trust during the COVID-19 pandemic: intervention time series analysis.

Objective: To determine the impact of the COVID-19 pandemic on antimicrobial consumption and trends of therapeutic drugs for COVID-19 treatments, including corticosteroids, remdesivir and monoclonal antibodies (tocilizumab) from April 2017 to September 2022 in a secondary care NHS Trust in England. Methods: A retrospective intervention time series analysis was conducted for April 2017 to September 2022 at the Mid Yorkshire Teaching NHS Trust. Data were retrieved from the pharmacy dispensing system as defined daily doses (DDDs) monthly and reported per 1000 occupied bed days (OBDs). Antimicrobial consumption and COVID-19 treatment options were measured. DDDs were calculated according to the classification of antimicrobials for systemic use (J01) and for other drugs classification. Trends for antimicrobial consumption and other therapeutic drugs for treating COVID-19 were also determined in each wave in England. Results: During the pandemic: total antibiotic consumption decreased from 826.4 to 728.2 DDDs per 1000 OBDs (P = 0.0067); piperacillin/tazobactam use increased (P < 0.0001) and ciprofloxacin use decreased (P < 0.0001); there were no changes in Access, Watch, Reserve antibiotic use, and the proportion of antifungal consumption was consistent throughout the study. The use of total antibiotics (P = 0.024), levofloxacin (P = 0.0007), piperacillin/tazobactam (P = 0.0015) and co-amoxiclav (P = 0.0198) increased during wave one. Consumption of COVID-19 treatment drugs was highest during wave two, with 624.3 DDDs per 1000 OBDs for dexamethasone (P = 0.4441), 6.8 DDDs per 1000 OBDs for remdesivir (P < 0.0001) and 35.01 DDDs per 1000 OBDs for tocilizumab (P = 0.2544). Discussion: This study determined the consumption of antimicrobials trends before and during the pandemic. The individual wave antimicrobial consumption indicates maximum consumption in the first wave, advocating for antimicrobial stewardship and preparedness for future pandemics.

Exploring drivers and challenges influencing antibiotic prescribing in outpatient settings and possible mitigation strategies in the United Arab Emirates: a qualitative study.

Objectives: Healthcare institutions implement antimicrobial stewardship (AMS) programmes to optimize the use of antibiotics. The focus is often on inpatient rather than outpatient settings. We aimed to explore perceptions of AMS stakeholders on effective interventions for appropriate antibiotic use in outpatient settings, and the role of clinical pharmacists in the AMS multidisciplinary team. Methods: A qualitative semi-structured interview study using thematic analysis by two researchers independently. Participants that practice AMS programmes were recruited from healthcare facilities in the United Arab Emirates (UAE). Interviews were conducted face to face or online and transcribed verbatim. Results: Four themes emerged: (i) Perceived factors leading to unnecessary or inappropriate antibiotic prescribing and their impact on patients and the community; (ii) current outpatient AMS activities and perceived barriers and facilitators for their sustainability; (iii) suggested outpatient AMS strategies to be implemented in outpatient settings; and (iv) perceived future AMS implementation barriers and suggested mitigation strategies. Conclusions: Several AMS interventions, together with the presence of a clinical pharmacist, may be effective in improving antibiotic use in UAE outpatient settings. Future research should investigate the most appropriate AMS strategy considering barriers and possible mitigation strategies to ensure sustainability.

Feasibility, Effectiveness and Safety of Elastomeric Pumps for Delivery of Antibiotics to Adult Hospital Inpatients-A Systematic Review.

Elastomeric infusion pumps (EMPs) have been implemented in many fields, including analgesia, chemotherapy and cardiology. Their application in antimicrobials is mainly limited to the outpatient setting, but with a need to optimise inpatient antimicrobial treatment, the use of EMPs presents a potential option. This review aimed to identify if the use of EMPs within an inpatient setting is feasible, effective and safe for antimicrobial use. Criteria for inclusion were human studies that involved the treatment of an infection with intravenous antimicrobial agents via an EMP. A search strategy was developed covering both the indexed and grey literature, with all study designs included. The review found 1 eligible study enrolling 6 patients. There was strong patient preference for EMPs (6/6), and daily tasks were easily completed whilst attached to the EMP. Nurses (5/5) also preffered the pumps, and the majority reported them as easy to use. The review has identified the need for further research in the area. Evidence for the use of EMPs to administer antibiotics in the inpatient setting is scarce, and more work is needed to understand the advantages to patients, to healthcare workers and from an antimicrobial stewardship perspective. Potential disadvantages that may put patients at risk also need investigating.

Identification of antibiotic consumption targets for the management of Clostridioides difficile infection in hospitals- a threshold logistic modelling approach.

BACKGROUND: This study aims to demonstrate the utility of a threshold logistic approach to identifying thresholds for specific antibiotic use associated with Clostridioides difficile infection (CDI) in an English teaching hospital. METHODS: A combined approach of nonlinear modeling and logistic regression, named threshold logistic, was used to identify thresholds and risk scores in hospital-level antibiotic use associated with hospital-onset, healthcare-associated (HOHA) CDI cases. RESULTS: Using a threshold logistic regression approach, an incidence greater than 0.2645 cases/1000 occupied bed-days (OBD; 85th percentile) was determined as the cutoff rate to define a critical (high) incidence rate of HOHA CDI. Fluoroquinolones and piperacillin-tazobactam were found to have thresholds at 84.8 and 54 defined daily doses (DDD)/1000 OBD, respectively. Analysis of data allowed calculating risk scores for HOHA CDI incidence rates exceeding the 85th percentile, i.e. entering critical incidence level. The threshold-logistic model also facilitated performing 'what-if scenarios' on future values of fluoroquinolones and piperacillin-tazobactam use to understand how HOHA CDI incidence rates may be affected. CONCLUSION: Using threshold logistic analysis, critical incidence levels and antibiotic use targets to control HOHA CDI were determined. Threshold logistic models can be used to inform and enhance the effective design and implementation of antimicrobial stewardship programs.

Exploring thresholds and interaction effects among antibiotic usage, covariates, and their effect on antibiotic resistance using an extended-spectrum ß-Lactamase-producing Klebsiella pneumoniae case.

BACKGROUND: This study was aimed to explore thresholds with interaction effects among antibiotic usage, covariates (alcohol-based hand rub (ABHR)), and their effect on extended-spectrum ß-lactamase-producing Klebsiella pneumoniae (ESBL-producing K. pneumoniae) in hospitalized patients. METHODS: Multivariate Adaptive Regression Spline models were used. These considered second-order interactions among antibiotic use and ABHR in addition to potential thresholds that further improve explained variance in the ESBL-producing K. pneumoniae response. The study involved collecting monthly hospital-level data for January 2017-December 2021. RESULTS: Analysis of the main effects showed that third-generation cephalosporins above 2.00 DDD/100 occupied bed days (OBD) generally increased ESBL-producing K. pneumoniae incidence (cases/100 OBD). Levels of ABHR above 6.61 L/100 OBD were shown to generally decrease ESBL-producing K. pneumoniae incidence. Second-order interactions revealed that when third-generation cephalosporin use was greater than 3.71 DDD/100 OBD, and ABHR was greater than 6.6 L/100 OBD (same as main effect threshold), ABHR partially lost effectiveness in its ability to reduce ESBL-producing K. pneumoniae incidence. This demonstrates the importance of not exceeding the identified thresholds of 3.71 DDD/100 OBD for third-generation cephalosporin use. CONCLUSION: The main-effect thresholds in third-generation cephalosporins and ABHR, and the identified interaction between third-generation cephalosporins and ABHR can inform effective hospital antimicrobial stewardship.

Public knowledge of antibiotics, self-medication, and household disposal practices in Jordan.

BACKGROUND: This study aimed to assess public understanding of antibiotics, self-medication, and drug disposal practices. METHODS: A cross-sectional self-administered online survey was undertaken in Jordan. RESULTS: The study was completed by 1,105 participants. When asked about their knowledge of antibiotics, rational antibiotic use, and disposal practices, 16% percent believed they should discontinue antibiotics once they felt better, and 12% agreed to take the same antibiotics prescribed to others for the same illness. Self-medication with antibiotics was practiced by 44% of the participants. Prior experience, healthcare costs, and pharmacy location were all major determinants of self-medication. Only 6.4% of unneeded antibiotics were returned to the pharmacy, 60% were kept at home, and 26.6% were disposed of at home. Almost half of those who kept the antibiotics said they would use them again, and one-third said they would give them to friends and family. Respondents who had used antibiotics within the previous 6 months (p = 0.052) and relied on medication leaflets (p = 0.031) and physician recommendations (p = 0.001) were less likely to self-medicate with antibiotics. CONCLUSIONS: The study highlighted areas of inappropriate use of antibiotics, self-medication and the improper antibiotic disposal that can inform antimicrobial stewardship.

Procalcitonin Evaluation of Antibiotic Use in COVID-19 Hospitalised Patients (PEACH): Protocol for a Retrospective Observational Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Although COVID-19 is a viral illness, many patients admitted to hospital are prescribed antibiotics, based on concerns that COVID-19 patients may experience secondary bacterial infections, and the assumption that they may respond well to antibiotic therapy. This has led to an increase in antibiotic use for some hospitalised patients at a time when accumulating antibiotic resistance is a major global threat to health. Procalcitonin (PCT) is an inflammatory marker measured in blood samples and widely recommended to help diagnose bacterial infections and guide antibiotic treatment. The PEACH study will compare patient outcomes from English and Welsh hospitals that used PCT testing during the first wave of the COVID-19 pandemic with those from hospitals not using PCT. It will help to determine whether, and how, PCT testing should be used in the NHS in future waves of COVID-19 to protect patients from antibiotic overuse. PEACH is a retrospective observational cohort study using patient-level clinical data from acute hospital Trusts and Health Boards in England and Wales. The primary objective is to measure the difference in antibiotic use between COVID-19 patients who did or did not have PCT testing at the time of diagnosis. Secondary objectives include measuring differences in length of stay, mortality, intensive care unit admission, and resistant bacterial infections between these groups.

COVID-19 Mixed Impact on Hospital Antimicrobial Stewardship Activities: A Qualitative Study in UK-Based Hospitals.

Antimicrobial resistance (AMR) is a well-known global threat due to the subsequent increase in antimicrobial usage. Several antimicrobial stewardship (AMS) strategies have been implemented to curb irrational prescribing and reduce the AMR burden. However, since the beginning of the COVID-19 pandemic, it has enormously impacted the healthcare system and jeopardized public health, causing millions of deaths globally. Our semi-structured qualitative study aimed to explore the impact of COVID-19 on AMS activities in the UK hospitals. Seventeen interviews were conducted with health care professionals who were part of AMS teams (consultant medical microbiologists, infectious disease consultants, antimicrobial pharmacists). Interviews were audio-recorded and transcribed. An inductive thematic framework was adopted to analyse and create the themes. After agreement of the hierarchical framework definition, all transcripts were coded accordingly. Four main themes and 15 sub-themes were identified. These main themes were: (1) AMS activities or strategies before and during the pandemic; (2) challenges to implementing AMS activities before and during the pandemic; (3) information from public authorities on AMS during the pandemic; and (4) new AMS activities/strategies adopted during the pandemic. Staff vacancies, redeploying of AMS staff to other duties and meeting the burden related to the COVID-19 and lack of resources were the most frequently identified contributing factors to withheld AMS activities during the pandemic. However, modifications to the hybrid working environment, i.e., remote or flexible working, allowed for resumption of AMS activities including virtual ward rounds, virtual meetings and other activities. Further research needs to assess the impact of the hybrid delivery system on AMS activities.

Exploring Antimicrobial Stewardship Influential Interventions on Improving Antibiotic Utilization in Outpatient and Inpatient Settings: A Systematic Review and Meta-Analysis.

Antimicrobial stewardship interventions are targeted efforts by healthcare organizations to optimize antimicrobial use in clinical practice. The study aimed to explore effective interventions in improving antimicrobial use in hospitals. Literature was systemically searched for interventional studies through PubMed, CINAHL, and Scopus databases that were published in the period between January 2010 to April 2022. A random-effects model was used to pool and evaluate data from eligible studies that reported antimicrobial stewardship (AMS) interventions in outpatient and inpatient settings. Pooled estimates presented as proportions and standardized mean differences. Forty-eight articles were included in this review: 32 in inpatient and 16 in outpatient settings. Seventeen interventions have been identified, and eight outcomes have been targeted. AMS interventions improved clinical, microbiological, and cost outcomes in most studies. When comparing non-intervention with intervention groups using meta-analysis, there was an insignificant reduction in length of stay (MD: -0.99; 95% CI: -2.38, 0.39) and a significant reduction in antibiotics' days of therapy (MD: -2.73; 95% CI: -3.92, -1.54). There were noticeable reductions in readmissions, mortality rates, and antibiotic prescriptions post antimicrobial stewardship multi-disciplinary team (AMS-MDT) interventions. Studies that involved a pharmacist as part of the AMS-MDT showed more significant improvement in measured outcomes than the studies that did not involve a pharmacist.

A Threshold Logistic Modelling Approach for Identifying Thresholds between Antibiotic Use and Methicillin-Resistant Staphylococcus aureus Incidence Rates in Hospitals.

The aim of this study was to demonstrate the utility of threshold logistic modelling, an innovative approach in identifying thresholds and risk scores in the context of population antibiotic use associated with methicillin-resistant Staphylococcus aureus (MRSA) incidence rates in hospitals. The study also aimed to assess the impact of exceeding those thresholds that resulted in increased MRSA rates. The study was undertaken in a 700-bed hospital in England between January 2015 and December 2021 (84 monthly observations). By employing the threshold logistic modelling approach, we: (i) determined the cut-off percentile value of MRSA incidence that defines a critical level of MRSA; (ii) identified thresholds for fluoroquinolone and co-amoxiclav use that would accelerate MRSA incidence rates and increase the probability of reaching critical incidence levels; (iii) enabled a better understanding of the effect of antibiotic use on the probability of reaching a critical level of resistant pathogen incidence; (iv) developed a near real-time performance monitoring feedback system; (v) provided risk scores and alert signals for antibiotic use, with the ability to inform hospital policies, and control MRSA incidence; and (vi) provided recommendations and an example for the management of pathogen incidence in hospitals. Threshold logistic models can help hospitals determine quantitative targets for antibiotic usage and can also inform effective antimicrobial stewardship to control resistance in hospitals. Studies should work toward implementing and evaluating the proposed approach prospectively, with the aim of determining the best counter-measures to mitigate the risk of increased resistant pathogen incidence in hospitals.

Identifying Antibiotic Use Targets for the Management of Antibiotic Resistance Using an Extended-Spectrum ß-Lactamase-Producing Escherichia coli Case: A Threshold Logistic Modeling Approach.

The aim of this study was to develop a logistic modeling concept to improve understanding of the relationship between antibiotic use thresholds and the incidence of resistant pathogens. A combined approach of nonlinear modeling and logistic regression, named threshold logistic, was used to identify thresholds and risk scores in hospital-level antibiotic use associated with hospital-level incidence rates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli). Threshold logistic models identified thresholds for fluoroquinolones (61.1 DDD/1000 occupied bed days (OBD)) and third-generation cephalosporins (9.2 DDD/1000 OBD) to control hospital ESBL-producing E. coli incidence. The 60th percentile of ESBL-producing E. coli was determined as the cutoff for defining high incidence rates. Threshold logistic analysis showed that for every one-unit increase in fluoroquinolones and third-generation cephalosporins above 61.1 and 9.2 DDD/1000 OBD levels, the average odds of the ESBL-producing E. coli incidence rate being ≥60th percentile of historical levels increased by 4.5% and 12%, respectively. Threshold logistic models estimated the risk scores of exceeding the 60th percentile of a historical ESBL-producing E. coli incidence rate. Threshold logistic models can help hospitals in defining critical levels of antibiotic use and resistant pathogen incidence and provide targets for antibiotic consumption and a near real-time performance monitoring feedback system.

Pharmacists' Knowledge, Attitudes, Behaviors and Information Sources on Antibiotic Use and Resistance in Jordan.

Antimicrobial resistance (AMR) is a serious healthcare problem that affects public health globally. Appropriate understanding and knowledge of prudent antimicrobial use and resistance, along with providing evidence-based information sources, are needed for informed antibiotic prescribing practices. This study aimed to assess the knowledge, opportunity, motivation, behavior of pharmacists and their information sources regarding antibiotic use and resistance in Jordan. An online cross-sectional questionnaire was developed and administered to pharmacists during the period of July-September 2021. The survey is an adapted version of the validated European Centre for Disease Prevention and Control (ECDC) survey for antibiotic use and resistance. Pharmacists from all sectors (n = 384), of whom 276 (71.9%) were community pharmacists, completed an online questionnaire. While respondents scored highly (>87%) on knowledge on effective use, unnecessary use, and associated side effects of antibiotics, lower scores were recorded for knowledge on the spread of antibiotic resistance (52.9%). Pharmacists support easy access to guidelines on managing infections in 56% of cases, and easy access to materials advising prudent antibiotic use and resistance in 39.8% of cases. One-third of respondents (37.0%) reported no knowledge of any initiatives on antibiotic awareness and resistance. Pharmacists were aware (13.3%), unaware (36.2%), or unsure (50.5%) of the existence of a national antibiotic resistance action plan. Pharmacists indicated an interest in receiving more information on resistance to antibiotics (55.2%), medical conditions for which antibiotics are used (53.1%), how to use antibiotics (45.1%), prescribing of antibiotics (34.4%), and links between the health of humans, animals, and the environment (28.6%). Findings can inform antimicrobial stewardship with required interventions to improve antibiotic use.

Antimicrobial consumption in patients with COVID-19: a systematic review and meta-analysis.

INTRODUCTION: Since the onset of the pandemic, prescribing antimicrobials has become a common practice to treat patients infected with COVID-19. AREAS COVERED: A systematic literature search was performed in the electronic databases MEDLINE, CINAHL, WHO COVID-19 database, including EMBASE, Scopus, WHO-COVID, LILACS, and Google Scholar to identify original articles published up to 31 July 2021. A random-effects model was used to estimate the pooled prevalence or proportion of antimicrobial consumption among COVID-19 patients. EXPERT OPINION: We identified 43 original articles, 33 studies from high-income countries, six from upper-middle-income countries, and four from lower-middle-income countries. Most of the studies presented data from hospital or secondary health-care settings (n = 34). Included studies measured antimicrobial consumption as Daily Defined Doses (DDD) or day of therapy (DOT) or percentage. A total of 19 studies measured antimicrobial consumption as DDDs or DOT. Meta-analysis revealed an overall high antimicrobial consumption of 68% (95% CI: 60% to 75%). The subgroup analysis found a lower consumption in high-income countries (58%, 95% CI: 48% to 67%), compared with lower and middle-income countries (89%, 95% CI: 82% to 94%). High antimicrobial consumption found in COVID-19 patients demands implementation of appropriate antimicrobial stewardship interventions.

Use of Procalcitonin during the First Wave of COVID-19 in the Acute NHS Hospitals: A Retrospective Observational Study.

A minority of patients presenting to hospital with COVID-19 have bacterial co-infection. Procalcitonin testing may help identify patients for whom antibiotics should be prescribed or withheld. This study describes the use of procalcitonin in English and Welsh hospitals during the first wave of the COVID-19 pandemic. A web-based survey of antimicrobial leads gathered data about the use of procalcitonin testing. Responses were received from 148/151 (98%) eligible hospitals. During the first wave of the COVID-19 pandemic, there was widespread introduction and expansion of PCT use in NHS hospitals. The number of hospitals using PCT in emergency/acute admissions rose from 17 (11%) to 74/146 (50.7%) and use in Intensive Care Units (ICU) increased from 70 (47.6%) to 124/147 (84.4%). This increase happened predominantly in March and April 2020, preceding NICE guidance. Approximately half of hospitals used PCT as a single test to guide decisions to discontinue antibiotics and half used repeated measurements. There was marked variation in the thresholds used for empiric antibiotic cessation and guidance about interpretation of values. Procalcitonin testing has been widely adopted in the NHS during the COVID-19 pandemic in an unevidenced, heterogeneous way and in conflict with relevant NICE guidance. Further research is needed urgently that assesses the impact of this change on antibiotic prescribing and patient safety.

Impact of an antimicrobial stewardship intervention on appropriateness of prescribing for community-acquired pneumonia in an Australian regional hospital.

Community-acquired pneumonia (CAP) is the second commonest indication for antibiotic use in Australian hospitals and is therefore a frequent target for antimicrobial stewardship. A single-centre prospective study was conducted in a regional referral hospital comparing management of adult patients with CAP before and after an educational intervention. We demonstrated a reduction in duration of therapy and reduced inappropriate use of ceftriaxone-based regimens for non-severe CAP.

Outcomes of multisite antimicrobial stewardship programme implementation with a shared clinical decision support system.

Background: Studies evaluating antimicrobial stewardship programmes (ASPs) supported by computerized clinical decision support systems (CDSSs) have predominantly been conducted in single site metropolitan hospitals. Objectives: To examine outcomes of multisite ASP implementation supported by a centrally deployed CDSS. Methods: An interrupted time series study was conducted across five hospitals in New South Wales, Australia, from 2010 to 2014. Outcomes analysed were: effect of the intervention on targeted antimicrobial use, antimicrobial costs and healthcare-associated Clostridium difficile infection (HCA-CDI) rates. Infection-related length of stay (LOS) and standardized mortality ratios (SMRs) were also assessed. Results: Post-intervention, antimicrobials targeted for increased use rose from 223 to 293 defined daily doses (DDDs)/1000 occupied bed days (OBDs)/month (+32%, P < 0.01). Conversely, antimicrobials targeted for decreased use fell from 254 to 196 DDDs/1000 OBDs/month (-23%; P < 0.01). These effects diminished over time. Antimicrobial costs decreased initially (-AUD$64551/month; P < 0.01), then increased (+AUD$7273/month; P < 0.01). HCA-CDI rates decreased post-intervention (-0.2 cases/10 000 OBDs/month; P < 0.01). Proportional LOS reductions for key infections (respiratory from 4.8 to 4.3 days, P < 0.01; septicaemia 6.8 to 6.1 days, P < 0.01) were similar to background LOS reductions (2.1 to 1.9 days). Similarly, infection-related SMRs (observed/expected deaths) decreased (respiratory from 1.1 to 0.75; septicaemia 1.25 to 0.8; background rate 1.19 to 0.90. Conclusions: Implementation of a collaborative multisite ASP supported by a centrally deployed CDSS was associated with changes in targeted antimicrobial use, decreased antimicrobial costs, decreased HCA-CDI rates, and no observable increase in LOS or mortality. Ongoing targeted interventions are suggested to promote sustainability.

Discontinuation of peri-operative gentamicin use for indwelling urinary catheter manipulation in orthopaedic surgery.

BACKGROUND: Gentamicin has historically been used prior to insertion and removal of indwelling urinary catheters (IDCs) around elective joint replacement surgery to prevent infection; however, this indication is not recognized in the Australian Therapeutic Guidelines: Antibiotic and the paradigm for safe use of gentamicin has shifted. METHODS: The antimicrobial stewardship team of a 500 bed tertiary regional hospital performed a retrospective clinical study of gentamicin IDC prophylaxis around total hip and knee arthroplasties. Results were presented to the orthopaedic surgeons. A literature review identified no guidelines to support gentamicin prophylaxis and only a very low risk of bacteraemia associated with IDC insertion/removal in patients with established bacteriuria. Consensus was reached with the surgeons to discontinue this practice. Subsequent prospective data collection was commenced to determine effectiveness, with weekly feedback to the Department Head of Orthopaedics. RESULTS: Data from 137 operations pre-intervention (6 months) were compared with 205 operations post-intervention (12 months). The median patient age was 72 years in both groups. Following the intervention, reductions in gentamicin use were demonstrated for IDC insertion (59/137 (42%) to 4/205 (2%), P < 0.01) and removal (39/137 (28%) to 6/205 (3%), P < 0.01). No gentamicin use was observed during the final 40 weeks of the post-intervention period. There were no significant differences between the groups for pre-operative bacteriuria, surgical site infections or acute kidney injury. CONCLUSION: A collaborative approach using quality improvement methodology can lead to an evidence-based reappraisal of established practice. Regular rolling audits and timely feedback were useful in sustaining change.

Posaconazole Therapeutic Drug Monitoring in a Regional Hospital Setting.

BACKGROUND: Posaconazole therapeutic drug monitoring (TDM) is recommended to promote effective antifungal prophylaxis, but its utility has yet to be optimized. Breakthrough invasive fungal infections have been reported with serum concentrations <700 mcg/L, but there is little evidence to determine the optimal serum concentration for efficacy or concentrations associated with toxicity. Challenges for effective monitoring are greater in settings without posaconazole TDM facilities because of the long turnaround time before receipt of results. METHODS: Thirty-eight TDM episodes were performed on 18 patients in a regional center in Australia during a 30-month period. Australian guidelines recommend a trough serum concentration of ≥700 mcg/L. The response to concentrations below the recommendation threshold (700 mcg/L), the final serum plasma concentration for each patient, and the appropriateness of TDM were evaluated. RESULTS: A total of 19 (50%) concentrations were recorded to be < 700 mcg/L. Of these 19 concentrations, the drug dose was increased on only 4 occasions. Eleven of 18 patients (61%) had initial concentrations <700 mcg/L, with only 3 (27%) among those achieving final concentration ≥ 700 mcg/L; 5 patients with initial concentrations <700 mcg/L did not have any further TDM testing. Nine of the 18 (50%) patients had a final concentration <700 mcg/L. Five of 7 (71%) patients with initial concentrations ≥700 mcg/L had further TDM with no reasoning documented. CONCLUSIONS: The results demonstrate a lack of confidence and consistency in ordering, interpreting, and following up posaconazole concentrations. Therefore, the use of TDM should be carefully considered, especially in regional centers. Such settings should consider the practicalities of posaconazole TDM and try to improve the process to ensure consistency and optimization of patient care.