A strategy for designing voriconazole dosage regimens to prevent invasive pulmonary aspergillosis based on a cellular pharmacokinetics/pharmacodynamics model

Epidemiological characteristics of patients with invasive pulmonary aspergillosis infected with Aspergillus fumigatus from a tertiary hospital in Ningxia, China

Invasive pulmonary aspergillosis (IPA) is a severe fungal infection primarily caused by Aspergillus fumigatus, representing a significant burden on public health. This study aims to address the limitations in the epidemiological characteristics, risk factors and diagnostic approaches for IPA by identifying clinical characteristics, laboratory findings, and chest CT imaging features that distinguish IPA from Aspergillus fumigatus colonization (AFC). We conducted a retrospective analysis of 249 hospitalized patients, including 77 with IPA and 172 with AFC, at Ningxia Medical University General Hospital from January 2018 to December 2023. Our findings revealed that patients with IPA exhibited higher rates of hemoptysis, dyspnea, and fever compared to those with AFC. Laboratory results indicated elevated levels of galactomannan (GM), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and platelet count in IPA patients. Chest computed tomography imaging studies showed higher incidences of cavity, consolidation, ground-glass opacity, and halo sign in IPA patients. Voriconazole was the primary treatment for 75.3% of IPA patients, who also had longer hospital stays and higher treatment costs. Multivariate logistic regression identified GM, ESR, chronic obstructive pulmonary disease (COPD), and hypertension as significant risk factors for IPA. Our study highlights the necessity of developing enhanced diagnostic models that integrate GM and ESR biomarkers to improve the specificity and sensitivity of IPA diagnosis. These findings provide valuable insights for early diagnosis and optimized treatment strategies, potentially improving patient outcomes and reducing healthcare costs.

Therapeutic Drug Monitoring and Biomarkers; towards Better Dosing of Antimicrobial Therapy

Due to variability in pharmacokinetics and pharmacodynamics, clinical outcomes of antimicrobial drug therapy vary between patients. As such, personalised medication management, considering both pharmacokinetics and pharmacodynamics, is a growing concept of interest in the field of infectious diseases. Therapeutic drug monitoring is used to adjust and individualise drug regimens until predefined pharmacokinetic exposure targets are achieved. Minimum inhibitory concentration (drug susceptibility) is the best available pharmacodynamic parameter but is associated with many limitations. Identification of other pharmacodynamic parameters is necessary. Repurposing diagnostic biomarkers as pharmacodynamic parameters to evaluate treatment response is attractive. When combined with therapeutic drug monitoring, it could facilitate making more informed dosing decisions. We believe the approach has potential and justifies further research.

Pharmacokinetic/Pharmacodynamic Modeling and Application in Antibacterial and Antifungal Pharmacotherapy: A Narrative Review

Pharmacokinetics and pharmacodynamics are areas in pharmacology related to different themes in the pharmaceutical sciences, including therapeutic drug monitoring and different stages of drug development. Although the knowledge of these disciplines is essential, they have historically been treated separately. While pharmacokinetics was limited to describing the time course of plasma concentrations after administering a drug-dose, pharmacodynamics describes the intensity of the response to these concentrations. In the last decades, the concept of pharmacokinetic/pharmacodynamic modeling (PK/PD) emerged, which seeks to establish mathematical models to describe the complete time course of the dose-response relationship. The integration of these two fields has had applications in optimizing dose regimens in treating antibacterial and antifungals. The anti-infective PK/PD models predict the relationship between different dosing regimens and their pharmacological activity. The reviewed studies show that PK/PD modeling is an essential and efficient tool for a better understanding of the pharmacological activity of antibacterial and antifungal agents.

Variable cellular ivacaftor concentrations in people with cystic fibrosis on modulator therapy

The development of CFTR modulators has transformed the care of patients with cystic fibrosis (CF). Although the clinical efficacy of modulators depends on their concentrations in target tissues, the pharmacokinetic properties of these drugs in epithelia are not utilized to guide patient care. We developed assays to quantitate ivacaftor in cells and plasma from patients on modulator therapy, and our analyses revealed that cellular ivacaftor concentrations differ from plasma concentrations measured concurrently, with evidence of in vivo accumulation of ivacaftor in the cells of patients. While the nature of this study is exploratory and limited by a small number of patients, these findings suggest that techniques to measure modulator concentrations in vivo will be essential to interpreting their clinical impact, particularly given the evidence that ivacaftor concentrations influence the activity and stability of restored CFTR protein.