Effect of Cumulative Intravenous Voriconazole Dose on Renal Function in Hematological Patients

Clinical application of voriconazole in pediatric patients: a systematic review

The purpose of this study was to review the literature on the clinical use of voriconazole (VRC) in pediatric patients. MEDLINE, Embase, PubMed, Web of Science, and Cochrane Library were searched from January 1, 2000, to August 15, 2023 for relevant clinical studies on VRC use in pediatric patients. Data were collected based on inclusion and exclusion criteria, and a systematic review was performed on recent research related to the use of VRC in pediatric patients. This systematic review included a total of 35 observational studies among which there were 16 studies investigating factors influencing VRC plasma trough concentrations (Ctrough) in pediatric patients, 14 studies exploring VRC maintenance doses required to achieve target range of Ctrough, and 11 studies focusing on population pharmacokinetic (PPK) research of VRC in pediatric patients. Our study found that the Ctrough of VRC were influenced by both genetic and non-genetic factors. The optimal dosing of VRC was correlated with age in pediatric patients, and younger children usually required higher VRC doses to achieve target Ctrough compared to older children. Establishing a PPK model for VRC can assist in achieving more precise individualized dosing in children.

Intravenous perampanel as an alternative to the oral formulations in Japanese patients with epilepsy

OBJECTIVE

Perampanel is an oral anti-seizure medication, which is approved in Japan for focal-onset seizures, with/without focal to bilateral tonic-clonic seizures, as monotherapy/adjunctive therapy in patients aged 4 years and older. Treatment for generalized tonic-clonic seizures as adjunctive therapy in patients aged 12 years and older is approved as well. We evaluated the feasibility of intravenous (IV) administration of perampanel as an alternative to oral administration.

METHODS

Study 240 (NCT03754582) was an uncontrolled, open-label study of IV perampanel, conducted in 21 Japanese patients with epilepsy who received a stable dose of 8-12 mg/day of oral perampanel. Patients received 30-minute IV infusions at equivalent daily doses of oral perampanel for 4 days, then were switched back to oral perampanel. Safety, tolerability, plasma concentration, and maintenance of efficacy throughout the transition between IV and oral dosing of perampanel were assessed. As supportive data, a subgroup analysis was also conducted using data from healthy Japanese subjects (n = 18) who were enrolled in Study 050 (NCT03376997) investigating the pharmacokinetics and safety of IV perampanel in healthy subjects who received an IV infusion (30-, 60-, or 90-minute) of perampanel 12 mg and a single oral administration of perampanel 12-mg tablet.

RESULTS

In Study 240, the transition between 30-minute IV and oral perampanel dosing was associated with a ≤1.4-fold increase in the mean change in maximum observed concentration of perampanel. Seizure outcomes demonstrated no considerable changes in efficacy before, during, or after 30-minute IV dosing of perampanel. The safety profiles were similar between IV and oral formulations. In Study 050, the pharmacokinetics of 30- or 60-minute IV infusion of perampanel further support the interchangeability between oral and IV formulations in the Japanese subjects.

SIGNIFICANCE

These results support that 30-minute IV perampanel may be a potential short-term alternative to oral formulations for patients with epilepsy.

Prediction of plasma trough concentration of voriconazole in adult patients using machine learning

OBJECTIVE

Plasma trough concentration of voriconazole (VCZ) was associated with its toxicity and efficacy. However, the nonlinear pharmacokinetic characteristics of VCZ make it difficult to determine the relationship between clinical characteristics and its concentration. We intended to present a machine learning (ML)-based method to predict toxic plasma trough concentration of VCZ (>5 μg/mL).

METHODS

A single center retrospective study was conducted. Three ML algorithms were used to estimate the concentration in adult patients, including random forest (RF), gradient boosting (GB), and extreme gradient boosting (XGBoost). The importance of variables was recognized by the SHapley Additive exPlanations (SHAP) method. In addition, an external validation set was used to validate the robustness of models.

RESULTS

A total of 1318 VCZ plasma concentration were included, with 33 variables enrolled in the model. Nine classification models were developed using the RF, GB, and XGBoost algorithms. Most models performed well for both the training set and test set, with an average balanced accuracy (BA) of 0.704 and an average accuracy (ACC) of 0.788. In addition, the average Matthews correlation coefficient value reached 0.484, which indicated the predicted values are meaningful. Based on the average BA and ACC values, the predictive ability of the models can be ranked from best to worst as follows: younger adult models > mixed models > elderly models, and XGBoost models > GBT models > RF models. The SHAP results showed that the top five influencing factors in younger adult patients (<60 years) were albumin, total bile acid (TBA), platelets count, age, and inflammation, while the top five influencing factors in elderly patients were albumin, TBA, aspartate aminotransferase, creatinine, and alanine aminotransferase. Furthermore, the prediction of external validation set for VCZ concentrations verified the high reliability of the models, for the ACC value of 0.822 by the best model.

CONCLUSIONS

The ML models can be reliable tools for predicting toxic concentration exposure of VCZ. The SHAP results may provide useful guidelines for dosage adjustment of VCZ.

Factors influencing plasma concentration of voriconazole and voriconazole- N-oxide in younger adult and elderly patients

Background: Voriconazole (VCZ) metabolism is influenced by many factors. Identifying independent influencing factors helps optimize VCZ dosing regimens and maintain its trough concentration (C₀) in the therapeutic window. Methods: We conducted a prospective study investigating independent factors influencing VCZ C₀ and the VCZ C₀ to VCZ N-oxide concentration ratio (C₀/C_N) in younger adults and elderly patients. A stepwise multivariate linear regression model, including the IL-6 inflammatory marker, was used. The receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive effect of the indicator. Results: A total of 463 VCZ C₀ were analyzed from 304 patients. In younger adult patients, the independent factors that influenced VCZ C₀ were the levels of total bile acid (TBA) and glutamic-pyruvic transaminase (ALT) and the use of proton-pump inhibitors. The independent factors influencing VCZ C₀/C_N were IL-6, age, direct bilirubin, and TBA. The TBA level was positively associated with VCZ C₀ (ρ = 0.176, p = 0.019). VCZ C₀ increased significantly when the TBA levels were higher than 10 μmol/L (p = 0.027). ROC curve analysis indicated that when the TBA level ≥4.05 μmol/L, the incidence of a VCZ C₀ greater than 5 μg/ml (95% CI = 0.54-0.74) (p = 0.007) increased. In elderly patients, the influencing factors of VCZ C₀ were DBIL, albumin, and estimated glomerular filtration rate (eGFR). The independent factors that affected VCZ C₀/C_N were eGFR, ALT, γ-glutamyl transferase, TBA, and platelet count. TBA levels showed a positive association with VCZ C₀ (ρ = 0.204, p = 0.006) and C₀/C_N (ρ = 0.342, p < 0.001). VCZ C₀/C_N increased significantly when TBA levels were greater than 10 μmol/L (p = 0.025). ROC curve analysis indicated that when the TBA level ≥14.55 μmol/L, the incidence of a VCZ C₀ greater than 5 μg/ml (95% CI = 0.52-0.71) (p = 0.048) increased. Conclusion: TBA level may serve as a novel marker for VCZ metabolism. eGFR and platelet count should also be considered when using VCZ, especially in elderly patients.

Pharmacological management of antifungal agents in pulmonary aspergillosis: an updated review

INTRODUCTION

Aspergillus may cause different types of lung infections: invasive, chronic pulmonary or allergic bronchopulmonary aspergillosis. Pharmacological management with antifungals poses as a challenge. Patients diagnosed with pulmonary aspergillosis are complex, as well as the problems associated with antifungal agents.

AREAS COVERED

This article reviews the pharmacology of antifungal agents in development and currently used to treat pulmonary aspergillosis, including the mechanisms of action, pharmacokinetics, pharmacodynamics, dosing, therapeutic drug monitoring and safety. Recommendations to manage situations that arise in daily clinical practice are provided. A literature search of PubMed was conducted on November 15^th, 2020 and updated on March 30^th, 2021.

EXPERT OPINION

Recent and relevant developments in the treatment of pulmonary aspergillosis have taken place. Novel antifungals with new mechanisms of action that extend antifungal spectrum and improve pharmacokinetic-related aspects, drug-drug interactions and safety are under current study. For those antifungals already marketed, new data related to pharmacokinetics, pharmacodynamics, dose adjustments in special situations, therapeutic drug monitoring and safety are available. To maximize efficacy and reduce the risk of associated toxicities, it is essential to choose the most appropriate antifungal; optimize its dose, interval, route of administration and length of treatment; and prevent side effects.

A Valid Warning or Clinical Lore: an Evaluation of Safety Outcomes of Remdesivir in Patients with Impaired Renal Function from a Multicenter Matched Cohort

Per prescribing guidance, remdesivir is not recommended for SARS-CoV-2 in patients with renal disease given the absence of safety data in this patient population. This study was a multicenter, retrospective chart review of hospitalized patients with SARS-CoV-2 who received remdesivir.

Per prescribing guidance, remdesivir is not recommended for SARS-CoV-2 in patients with renal disease given the absence of safety data in this patient population. This study was a multicenter, retrospective chart review of hospitalized patients with SARS-CoV-2 who received remdesivir. Safety outcomes were compared between patients with an estimated creatinine clearance (eCrCl) of <30 ml/min and an eCrCl of ≥30 ml/min. The primary endpoint was acute kidney injury (AKI) at the end of treatment (EOT). Of 359 patients who received remdesivir, 347 met inclusion criteria. Patients with an eCrCl of <30 ml/min were older {median, 80 years (interquartile range [IQR], 63.8 to 89) versus 62 (IQR, 54 to 74); P < 0.001}, were more likely to be on vasopressors on the day of remdesivir administration (30% versus 12.7%; P = 0.003), and were more likely to be mechanically ventilated during remdesivir therapy (27.5% versus 12.4%; P = 0.01) than those with an eCrCl of ≥30 ml/min. Despite these confounders, there was no significant difference in the frequency of EOT AKI (5% versus 2.3%; P = 0.283) or early discontinuation due to abnormal liver function tests (LFTs) (0% versus 3.9%; P = 0.374). Of the 5% of patients who developed EOT AKI on remdesivir with an eCrCl <30 ml/min, no cases were attributable to remdesivir administration per the treating physician. Comparable safety outcomes were observed when 1:1 nearest neighbor matching was applied to account for baseline confounders. In conclusion, remdesivir administration was not significantly associated with increased EOT AKI in patients with an eCrCl of <30 ml/min compared to patients with an eCrCl of ≥30 ml/min.

Candidiasis and Mechanisms of Antifungal Resistance

Candidiasis can be present as a cutaneous, mucosal or deep-seated organ infection, which is caused by more than 20 types of Candida sp., with C. albicans being the most common. These are pathogenic yeast and are usually present in the normal microbiome. High-risk individuals are patients of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), organ transplant, and diabetes. During infection, pathogens can adhere to complement receptors and various extracellular matrix proteins in the oral and vaginal cavity. Oral and vaginal Candidiasis results from the overgrowth of Candida sp. in the hosts, causing penetration of the oral and vaginal tissues. Symptoms include white patches in the mouth, tongue, throat, and itchiness or burning of genitalia. Diagnosis involves visual examination, microscopic analysis, or culturing. These infections are treated with a variety of antifungals that target different biosynthetic pathways of the pathogen. For example, echinochandins target cell wall biosynthesis, while allylamines, azoles, and morpholines target ergosterol biosynthesis, and 5-Flucytosine (5FC) targets nucleic acid biosynthesis. Azoles are commonly used in therapeutics, however, because of its fungistatic nature, Candida sp. evolve azole resistance. Besides azoles, Candida sp. also acquire resistance to polyenes, echinochandins, and 5FC. This review discusses, in detail, the drug resistance mechanisms adapted by Candida sp.

Resveratrol Delivery from Implanted Cyclodextrin Polymers Provides Sustained Antioxidant Effect on Implanted Neural Probes

Intracortical microelectrodes are valuable tools used to study and treat neurological diseases. Due in large part to the oxidative stress and inflammatory response occurring after electrode implantation, the signal quality of these electrodes decreases over time. To alleviate this response, resveratrol, a natural antioxidant which elicits neuroprotective effects through reduction of oxidative stress, was utilized. This work compares traditional systemic delivery of resveratrol to the novel cyclodextrin polymer (pCD) local delivery approach presented herein, both in vitro and in vivo. The pCD displayed an extended resveratrol release for 100 days, as well as 60 days of free radical scavenging activity in vitro. In vivo results indicated that our pCD delivery system successfully delivered resveratrol to the brain with a sustained release for the entire short-duration study (up to 7 days). Interestingly, significantly greater concentrations of resveratrol metabolites were found at the intracortical probe implantation site compared to the systemic administration of resveratrol. Together, our pilot results provide support for the possibility of improving the delivery of resveratrol in an attempt to stabilize long-term neural interfacing applications.

Extrapolating Antifungal Animal Data to Humans - Is it reliable?

PURPOSE OF REVIEW

This article aimed to review animal models of antifungals and identifies human literature to assess if the extrapolation of results is reliable.

RECENT FINDINGS

Animal studies have helped identify AUC/MIC targets for new drugs and formulations such as isavuconazole and delayed release posaconazole that have translated to successful outcomes in humans. Models have also been influential in the identification of possible combination therapies for the treatment of aspergillosis, such as voriconazole and echinocandins. However, challenges are endured with animal models when it comes to replicating the pharmacokinetics of humans which has been exemplified with the newest itraconazole formulation. Additionally, animal models have displayed a survival benefit with the use of iron chelators and amphotericin for mucormycosis which was not demonstrated in humans.

SUMMARY

Animal models have been a staple in the development and optimization of antifungal agents. They afford the ability to investigate uncommon diseases, such as invasive fungal infections, that would otherwise take years and many resources to complete. Although there are many benefits of animal models there are also shortcomings. This is why the reliability of extrapolating data from animal models to humans is often scrutinized.