Current practices and challenges of outpatient parenteral antimicrobial therapy: a narrative review

Feasibility of 24 h continuous-infusion cefiderocol administered by elastomeric pump in attaining an aggressive PK/PD target in the treatment of NDM-producing Klebsiella pneumoniae otomastoiditis

Objectives

Cefiderocol has emerged as a key treatment for managing MDR infections, and its time-dependent pharmacodynamics are optimized by prolonged infusion to maintain time above the MIC (T  > MIC). Whereas recent stability studies have shown cefiderocol remains stable up to 72 h in elastomeric pumps, its use in 24 h continuous infusions (CIs) for outpatient parenteral antibiotic therapy (OPAT) is undocumented. This case highlights its suitability for 24 h CI via elastomeric pumps in an OPAT setting, supported by therapeutic drug monitoring (TDM) to ensure optimal treatment efficacy.

Patient/case description

A 31-year-old male developed right-sided otomastoiditis caused by Klebsiella pneumoniae producing New Delhi MBL (NDM). Given the resistance profile and the need for prolonged therapy, cefiderocol was initiated at a daily dose of 6 g, administered by 24 h CI using an elastomeric pump. TDM was performed on Days 17 and 45 to assess plasma concentrations.

Results

TDM confirmed steady-state concentrations (C ss 25.2-28.1 mg/L), achieving optimal pharmacokinetic/pharmacodynamic (PK/PD) target attainment such as 100% T  > 4-6 MIC (free [f]C ss/MIC 10.58-11.80). Significant clinical improvement avoided the need for planned surgery, with no adverse events reported from the venous catheter, antibiotic therapy or elastomeric pump.

Conclusions

This approach underscores the feasibility and efficacy of cefiderocol administered by 24 h CI by means of an elastomeric pump and supported by real-time TDM in achieving an aggressive PK/PD target for the treatment of otomastoiditis due to NDM-producing K. pneumoniae.

A Cost-Effective Liquid Chromatography Method with Ultraviolet Detection for Identity Screening and Assay of Injectable Antibiotics

The presence of substandard and falsified (SF) medicines poses a significant challenge in resource-limited countries. Low-quality antibiotics are commonly reported in low-income countries. The present study aimed to develop and validate a liquid chromatography method with ultraviolet detection (LC-UV) for the identity screening and assay of 13 different injectable antibiotics, i.e., cefepime, amoxicillin, cefazolin, ampicillin, chloramphenicol, ceftazidime, ceftriaxone, cefotaxime, vancomycin, flucloxacillin, cloxacillin, benzylpenicillin, and meropenem in pharmaceutical formulations. Separation was performed using an XBridge C18 column and gradient elution. Mixtures of acetonitrile and 20 mM phosphate buffer (pH 8.0) were used as the mobile phases. The screening method was validated in terms of specificity and robustness, while linearity, precision, accuracy, and sensitivity were checked for the quantification method. The determination coefficients (R2) following linear regression were all greater than 0.999. The method showed good precision, with relative standard deviation values below 1%. The percentage recovery values were close to 100%. The method was applied to analyze 17 injectable antibiotics collected from the Ethiopian market. All commercial samples analyzed contained the correct API and met USP content specifications.

Clinical and patient-reported outcomes of self-administered outpatient parenteral antimicrobial treatment (S-OPAT): a scoping review

PURPOSE

This study aimed to provide a comprehensive overview of the existing literature on Self-administered Outpatient Parenteral Antimicrobial Therapy (S-OPAT), focusing on safety and clinical outcomes, factors influencing these outcomes, and the experiences of patients and caregivers.

METHODS

We searched the databases MEDLINE, CINAHL, Embase and Cochrane library. Publications were included if they reported on the clinical outcomes, safety, and/or experiences of patients and caregivers with S-OPAT. Study selection and data extraction were performed independently by two reviewers. Quantitative and qualitative data were summarized in data charting forms.

RESULTS

Forty-four studies were included: 41 primary studies, 2 systematic reviews and 1 clinical guideline. Clinical outcomes were reported in 17 and safety in 23 primary studies. Eleven studies compared S-OPAT to other OPAT delivery models. These studies showed that all models were generally comparable regarding clinical outcomes, but two studies reported an increased number of adverse events with S-OPAT. Nine studies, exploring a total of 7 potential risk factors, identified older age, comorbidities and Staphylococcus aureus infections as contributors to adverse events. The results of 14 studies on patient-centred outcomes showed that patients and caregivers considered S-OPAT a suitable alternative to other OPAT delivery models.

CONCLUSION

We conclude that S-OPAT is a viable model of care, demonstrating favourable clinical outcomes, although some safety concerns have been reported. The growing care demand now and in the future urges further development of S-OPAT care. Gaps of knowledge still exist, and we provide recommendations for future research.

Safety and Efficacy of Outpatient Parenteral Antibiotic Therapy (OPAT) in Patients With Infective Endocarditis: A Systematic Review and Meta-Analysis

BACKGROUND

Infective endocarditis (IE) is a life-threatening infection requiring prolonged intravenous antimicrobial therapy. Outpatient parenteral antibiotic therapy (OPAT) has emerged as an alternative to prolonged hospitalization, but its safety and efficacy in IE remain debated.

HYPOTHESIS

This systematic review and meta-analysis aimed to evaluate the outcomes of OPAT in IE patients.

METHODS

We systematically searched MEDLINE, Cochrane CENTRAL, Google Scholar, and Scopus for studies assessing OPAT in IE. Eligible studies included randomized controlled trials and observational studies reporting at least one relevant outcome (mortality, relapse, readmission, valve surgery, and adverse events). Pooled estimates were calculated using a random-effects model, and heterogeneity was assessed using the I² statistic. Risk of bias was evaluated using the ROBINS-I tool.

RESULTS

A total of 25 studies involving 2654 patients were included in the analysis. Patients treated with OPAT had a mortality rate of 0% during the treatment period and 5% during follow-up. The readmission rate was 16% during the treatment period, 4% of the patients had relapse, while 16% of patients underwent cardiac surgery. During follow-up, the readmission rate was 19%, with a relapse rate of 2%, and 14% of patients underwent cardiac surgery. Sensitivity analyses did not significantly affect the results, highlighting the robustness of the findings.

CONCLUSION

OPAT appears to be safe and effective for IE patients, with low mortality and relapse rates. However, increased readmission rates and IV-line complications warrant careful patient selection and monitoring. Further prospective trials are needed to refine OPAT protocols.

Delivery of Outpatient Parenteral Antimicrobial Therapy (OPAT) in an Ever-Changing National Health Service (UK): Benefits, Barriers, and Opportunities

Outpatient parenteral antimicrobial therapy (OPAT) is increasingly used to manage a broad range of infections, enabling patients to receive intravenous antibiotics safely outside inpatient settings. In this review, we examine the current landscape of OPAT practice across the United Kingdom (UK), assessing its clinical, economic, and operational impact. The benefits of OPAT for patients and the National Health Service (NHS), as well as its associated risks, are discussed. Additionally, we explore the challenges hindering its broader implementation within the UK. Finally, we highlight recent innovations and emerging applications of OPAT relevant to the NHS, underscoring key considerations for its future expansion and emphasising the need for a nationally coordinated strategy to realise its full potential.

OPTIONS-DC: Treatment Course Outcomes Following Outpatient Parenteral Antimicrobial Therapy RN-Led Multidisciplinary Care Conferences for People Who Use Drugs Hospitalized With Complex Infections

Background

Care of people who use drugs with infections and recommendations for long-term intravenous (IV) antimicrobials can be challenging. OPTIONS-DC is a multidisciplinary care conference developed in 2018 that utilizes a standardized conference tool led by outpatient parenteral antimicrobial therapy (OPAT) registered nurses (RNs) to guide treatment and discharge planning while focusing on harm reduction, ethical principles, and patient preferences. We describe treatment outcomes associated with OPTIONS-DC over the first 4 years of implementation.

Methods

Eligibility for OPTIONS-DC included history of substance use and recommendation for ≥10 days of IV antimicrobials. Conference data were collected prospectively; treatment course outcomes were collected retrospectively via a REDCap database.

Results

A total of 229 conferences were conducted for 202 unique patients between February 2018 and April 2022. Median conference length was 28 (interquartile range [IQR], 23.8-33.0) minutes. Median age was 38 years, 214 (93.5%) had active substance use, and 77 (33.6%) were houseless. The median recommended antimicrobial duration was 6 (IQR, 4-6) weeks. A total of 172 (75.1%) patients completed their antimicrobial course (80 [46.5%] inpatient and 92 [53.5%] outpatient). Average out-of-hospital antimicrobial days was 28.7 (standard deviation, 19.6). On multivariate analysis, having a primary care provider at the time of conference was associated with treatment completion (odds ratio, 4.50 [95% confidence interval, 1.55-13.07]; P < .01).

Conclusions

The OPAT RN-led OPTIONS-DC discharge planning conference is associated with high antimicrobial course completion rates, out-of-hospital completion, and out-of-hospital antimicrobial days.

PEGylated Silk Fibroin Nanoparticles for Oral Antibiotic Delivery: Insights into Drug-Carrier Interactions and Process Greenness

Insights into antibiotic-carrier interactions in the silk-fibroin-based nanoparticles and considerations on the formulation process greenness are limited. Hence, this work developed and characterized polyethylene glycol-functionalized silk fibroin nanoparticles for oral delivery of cefotaxime (PEG/SFPs-CTX), with a focus on the in silico simulations and process greenness. The particles were formulated by the two methods of co-condensation and adsorption. Dependent on the processes, the particles possessed spherical shape, smooth/rough surfaces, nanosize (170-650 nm), negative charge (-23 to -30 mV), and drug entrapment efficiency of ∼50%. The system rapidly absorbed the drug within 30 min, followed second-order kinetics, and significantly controlled the drug release rate in the simulated gastrointestinal system, which could bypass the stomach acidic pH. Interestingly, in silico docking revealed that CTX mostly bound strongly and noncovalently with fibroin, particularly at glutamic acid, via hydrogen bonds, van der Waals forces, and π-π interactions, while PEG enhanced the stability of the system. Molecular dynamics simulations confirmed the complex's stability under physiological conditions. Lastly, life cycle assessment analysis showed that both formulation methods were environmental friendly, with limited impacts on the ecosystem, and the adsorption method was "greener" than the co-condensation method.

Real-World Use of Dalbavancin in a United States Tertiary Referral Center

Introduction Outpatient management of serious bacterial infections can be difficult particularly in situations where outpatient parenteral antibiotic therapy may be difficult due to patient-specific factors such as history of medical non-compliance, unstable housing situations, and individuals who use injection drugs. Dalbavancin is a long-acting lipoglycopeptide antibiotic currently approved for the treatment of bacterial skin and soft tissue infections; however, it is often employed in the management of other infections caused by gram-positive organisms. Data regarding the off-label usage of dalbavancin remains an emerging area of study. Methods A retrospective cohort study of all 52 inpatients, ages 18-56, who received ≥1 dose of dalbavancin between November 2017 and February 2023 was conducted. Rates of treatment completion and clinical cure were assessed at 42 days post-dalbavancin treatment. Results Fifty-two adults were identified. Dalbavancin was used to treat skin/soft tissue infections in 12 patients (23.5%). Off-label uses accommodated for 40 patients, with diagnoses including as follows: bloodstream infection (21, 41.2%), osteomyelitis (12, 23.5%), septic arthritis (10, 13.3%), native valve infective endocarditis (six, 11.8%), prosthetic joint infection (three, 5.9%), epidural abscess (three, 5.9%), catheter-related bloodstream infection (one, 2%), and other infections (13, 25.5%). Among patients who completed therapy, cure, as assessed at day 42, was achieved in 35 (67.6%) patients. Intravenous (IV) drug and the need for facility placement to receive IV antibiotics use were the commonly cited reasons for dalbavancin utilization. Adverse events included mild elevation in serum aminotransferases which occurred in six patients (11.5%) and acute kidney injury which occurred in two (3.8%). There were no adverse events resulting in drug discontinuation. Conclusions Dalbavancin use, including off-label indications, such as bacteremia, septic arthritis, osteomyelitis, prosthetic joint infection, and others, appears safe and associated with favorable treatment responses. Therefore, it can be considered as an alternative treatment approach in patients who may not be candidates for traditional outpatient parenteral antimicrobial therapy.

A review of antimicrobial stability testing guidance for outpatient parenteral antimicrobial therapy programmes: is it time for global harmonization of testing frameworks?

Antimicrobial stability is an important consideration for treatment planning and service delivery in outpatient parenteral antimicrobial therapy (OPAT) programmes. Regulation of stability assessment varies by region, and conflicting guidance and standards exist. This leads to disparity of equity in access and limits availability of certain antimicrobials for managing infections in the outpatient setting. This review discusses the degree to which the international regulatory bodies have reached consensus on the regulation of antimicrobial stability testing, specifically for OPAT, and describes the variation in antimicrobial recommendations across regulatory bodies. The three major findings in this review are (i) variation in antimicrobial stability testing guidance, particularly in relation to temperature; (ii) lack of regulatory guidance, specifically in that some regions did not have OPAT guidelines; and (iii) only the UK's NHS has provided non-regulatory OPAT-specific advice on antimicrobial stability testing. In conclusion, harmonization of antimicrobial stability testing to form a global OPAT-specific regulatory framework, particularly considering 'areas of variation' amongst current guidance, is required. We call for the development of a global OPAT antimicrobial stability testing framework with consensus from accepted antimicrobial stability criteria, expert opinion and pharmacopoeial best practice.