Pharmacokinetics-pharmacodynamics, computer decision support technologies, and antimicrobial stewardship: the compass and rudder

Model-Informed Precision Dosing Software Tools for Dosage Regimen Individualization: A Scoping Review

BACKGROUND

Pharmacokinetic nomograms, equations, and software are considered the main tools available for Therapeutic Drug Monitoring (TDM). Model-informed precision dosing (MIPD) is an advanced discipline of TDM that allows dose individualization, and requires a software for knowledge integration and statistical calculations. Due to its precision and extensive applicability, the use of these software is widespread in clinical practice. However, the currently available evidence on these tools remains scarce.

OBJECTIVES

To review and summarize the available evidence on MIPD software tools to facilitate its identification, evaluation, and selection by users.

METHODS

An electronic literature search was conducted in MEDLINE, EMBASE, OpenAIRE, and BASE before July 2022. The PRISMA-ScR was applied. The main inclusion criteria were studies focused on developing software for use in clinical practice, research, or modelling.

RESULTS

Twenty-eight software were classified as MIPD software. Ten are currently unavailable. The remaining 18 software were described in depth. It is noteworthy that all MIPD software used Bayesian statistical methods to estimate drug exposure and all provided a population model by default, except NONMEN.

CONCLUSIONS

Pharmacokinetic software have become relevant tools for TDM. MIPD software have been compared, facilitating its selection for use in clinical practice. However, it would be interesting to standardize the quality and validate the software tools.

Building an antimicrobial stewardship program: A narrative of six years under the Donabedian perspective

Introduction: Antimicrobial resistance (AMR) is increasing and represents one of the world's major challenges. AMR increase morbimortality, length of hospital stay and costs. Antimicrobial Stewardship Programs (ASP) are one of the key strategies to promote the rational use of antimicrobials since AMR is mostly driven by antimicrobial consumption. Objective: To describe the ASP implementation in a teaching hospital from the perspective of Donabedian quality assessment and the Brazilian regulatory requirements. Method: This was a descriptive study with secondary data collection, including document review of the ASP. The study setting was a general public 392-bed hospital. The ASP activities were performed by the hospital infection control committee (HICC), hospital pharmacy (HP) and diagnostic support laboratory (DSL). The description of the three services mainly involved in the ASP was based on a quality assessment model involving the dimensions of "structure", "process" and "result" proposed by Donabedian. The distribution among dimensions was guided by the checklist of essential elements of the ASP that compose the Brazilian regulatory requirements. The checklist was applied in July, 2022, and the ASP results described from 2016 to 2021. Results: ASP actions have been gradually implemented since 2008 with the implementation of HICC and improved over the years. Regarding structure, the investments in technology were mapped, quantifying 26 computers and three software programs employed to computerize the ASP processes performed in specific physical areas by HICC, HP and DSL. Institutional guidelines used by HICC, HP and DSL guided clinical practices to operationalize ASP. The evaluation metrics improved for 10 indicators and worsened for four indicators. From the 60 items composing the checklist, the hospital met the requirements in 73.3% of the items (n = 44). Conclusion: This study described the implementation of ASP in a teaching hospital, applying the Donabedian perspective. Although the hospital still does not have a classic ASP model, there were investments to improve structure, processes and results, aiming to comply with international guidelines. A high proportion of key elements of ASP in the hospital were followed according to the Brazilian regulatory requirements. Aspects related to antimicrobial consumption and the emergence of microbial resistance deserve further investigations.

Pseudomonas aeruginosa Susceptibility in Spain: Antimicrobial Activity and Resistance Suppression Evaluation by PK/PD Analysis

Pseudomonas aeruginosa remains one of the major causes of healthcare-associated infection in Europe; in 2019, 12.5% of invasive isolates of P. aeruginosa in Spain presented combined resistance to ≥3 antimicrobial groups. The Spanish nationwide survey on P. aeruginosa antimicrobial resistance mechanisms and molecular epidemiology was published in 2019. Based on the information from this survey, the objective of this work was to analyze the overall antimicrobial activity of the antipseudomonal antibiotics considering pharmacokinetic/pharmacodynamic (PK/PD) analysis. The role of PK/PD to prevent or minimize resistance emergence was also evaluated. A 10,000-subject Monte Carlo simulation was executed to calculate the probability of target attainment (PTA) and the cumulative fraction of response (CFR) considering the minimum inhibitory concentration (MIC) distribution of bacteria isolated in ICU or medical wards, and distinguishing between sample types (respiratory and non-respiratory). Ceftazidime/avibactam followed by ceftolozane/tazobactam and colistin, categorized as the Reserve by the Access, Watch, Reserve (AWaRe) classification of the World Health Organization, were the most active antimicrobials, with differences depending on the admission service, sample type, and dose regimen. Discrepancies between EUCAST-susceptibility breakpoints for P. aeruginosa and those estimated by PK/PD analysis were detected. Only standard doses of ceftazidime/avibactam and ceftolozane/tazobactam provided drug concentrations associated with resistance suppression.

The Role of PK/PD Analysis in the Development and Evaluation of Antimicrobials

Pharmacokinetic/pharmacodynamic (PK/PD) analysis has proved to be very useful to establish rational dosage regimens of antimicrobial agents in human and veterinary medicine. Actually, PK/PD studies are included in the European Medicines Agency (EMA) guidelines for the evaluation of medicinal products. The PK/PD approach implies the use of in vitro, ex vivo, and in vivo models, as well as mathematical models to describe the relationship between the kinetics and the dynamic to determine the optimal dosing regimens of antimicrobials, but also to establish susceptibility breakpoints, and prevention of resistance. The final goal is to optimize therapy in order to maximize efficacy and minimize side effects and emergence of resistance. In this review, we revise the PK/PD principles and the models to investigate the relationship between the PK and the PD of antibiotics. Additionally, we highlight the outstanding role of the PK/PD analysis at different levels, from the development and evaluation of new antibiotics to the optimization of the dosage regimens of currently available drugs, both for human and animal use.

The Promise of Clinical Decision Support Systems Targetting Low-Resource Settings

Low-resource clinical settings are plagued by low physician-to-patient ratios and a shortage of high-quality medical expertise and infrastructure. Together, these phenomena lead to over-burdened healthcare systems that under-serve the needs of the community. Alleviating this burden can be undertaken by the introduction of clinical decision support systems (CDSSs); systems that support stakeholders (ranging from physicians to patients) within the clinical setting in their day-to-day activities. Such systems, which have proven to be effective in the developed world, remain to be under-explored in low-resource settings. This review attempts to summarize the research focused on clinical decision support systems that either target stakeholders within low-resource clinical settings or diseases commonly found in such environments. When categorizing our findings according to disease applications, we find that CDSSs are predominantly focused on dealing with bacterial infections and maternal care, do not leverage deep learning, and have not been evaluated prospectively. Together, these highlight the need for increased research in this domain in order to impact a diverse set of medical conditions and ultimately improve patient outcomes.

Time for Precision: A World Without Susceptibility Breakpoints

Interpretive criteria for in vitro susceptibility testing criteria, "susceptibility breakpoints," underpin the evaluation and selection of antimicrobial regimens. However, despite their strengths, susceptibility breakpoints are a relatively blunt instrument employed to address an extremely complex question-what is the likelihood of treatment success for individual patients? With regard to evaluating patients on a case-by-case basis, breakpoints merely allow us to account for pathogen susceptibility. This approach precludes consideration of drug exposures achieved in patients, thus overlooking half of the equation for predicting treatment success. Herein, we propose the framework for considering both pathogen- and patient-specific information to provide clinicians a means of evaluating antimicrobial regimens for individual patients through tools automating pharmacokinetic-pharmacodynamic target attainment analyses. Implementing these tools along with their acceptance by professional organizations will allow for a shift in the paradigm for how antimicrobials are selected and dosed-toward patient-centered care through precision medicine.