Voriconazole Dose Research Articles

“Crocus Flower”: Voriconazole-Induced Hallucinations and Visual Disturbances in a Patient with Recurrent Severe Vulvovaginitis—A Case Report on Irrational Drug Use

Background and Clinical Significance: Voriconazole is a commonly prescribed second-generation azole used for the prevention and treatment of fungal infections. This report seeks to elucidate the relationship between certain intravenous infusion parameters and the causality and severity of potential visual adverse events associated with voriconazole administration, despite existing reports of visual disturbances such as hallucinations and altered visual perception, the underlying causes of which remain inadequately understood. Case Presentation: This case report describes a 32-year-old female patient who experienced sudden hallucinations and visual impairments after receiving an initial dose of intravenous voriconazole for the treatment of recurrent severe vulvovaginitis caused by Candida glabrata. The symptoms quickly disappeared when the dosage and infusion rate were reduced as per the recommendations of the clinical pharmacist. Conclusions: This example emphasizes the possible negative drug responses linked to voriconazole, especially those provoked by its irrational use described as an inappropriate infusion rate, and the crucial role of clinical pharmacists in recognizing and handling these reactions.

Evaluation of the predictive performance of an online voriconazole dose calculator in children.

The dosing of voriconazole is challenging in pediatrics. One approach to improve the dosing is through the use of Bayesian concentration-guided dosing software. Our study assessed the predictive performance of a freely available online voriconazole dose calculator in pediatric patients "NextDose" ( https://www.nextdose.org/ ). Per each dose calculator, we predicted voriconazole concentrations. We did both a priori and a posteriori Bayesian predictions. A total of 51 patients were included in this study. For a priori predictions, bias was + 26% while imprecision was 70%. For a posteriori predictions, bias and imprecision were 0.01% and 46%. In conclusion, the available online dose calculator was overpredicting the concentrations before voriconazole observations were available. However, with just one measured concentration, the predictions improved with minimal bias and an acceptable level of imprecision. There is a need for more prospective studies evaluating the use of voriconazole dosing calculators in the pediatric population to assess if they can improve the achievement of therapeutic target concentrations compared to standard of care.

Evaluation of voriconazole therapeutic drug monitoring in malignant hematology patients.

Malignant hematology (MH) patients are susceptible to invasive fungal infections due to prolonged neutropenia and immunosuppressive therapies, which may require voriconazole therapy. Although voriconazole therapeutic drug monitoring (TDM) is common, evidence describing this practice is limited. The primary objective of this study was to describe the current practice of voriconazole TDM in MH patients at the Princess Margaret Cancer Centre (PM). A retrospective chart review was conducted for MH inpatients initiated on voriconazole at PM between November 1st, 2019 and November 13th, 2020. Data regarding voriconazole doses, levels, dose changes, and adverse effects were collected. The primary endpoint was the proportion of patients with initial voriconazole levels within therapeutic range (1-5 mg/L). Fifty-six patients were included in the study. The most common reason for starting voriconazole was possible invasive fungal infection (44 patients, 78.6%). Fifty-one patients (91.1%) received a loading dose of voriconazole, averaging 386.5 ± 78.5 mg. The average maintenance dose was 242.1 ± 45.7 mg. An average of 2.6 ± 2.9 levels were drawn per patient with an average level of 3.2 ± 2.4 mg/L. Forty-one patients (73.2%) had an initial voriconazole level within therapeutic range and 90 out of 145 total levels (62.1%) were within therapeutic range. There were 52 dose modifications made; 31 (60.8%) doses adjusted, 12 (23.5%) doses held, and 9 (17.6%) doses discontinued. For the 31 dose adjustments, 26 (83.9%) had a level redrawn and 17 (65.4%) of those levels were within therapeutic range. Twenty-three (41.1%) patients developed adverse effects, 8 (34.8%) of which were associated with supratherapeutic levels. Of these 23 patients, 19 (33.9%) experienced transaminitis, 3 (5.4%) experienced both transaminitis and neurotoxicity, and 1 (1.8%) experienced photopsia. Overall, 41 (73.2%) patients achieved an initial voriconazole level within therapeutic range. Of these 41 patients, 30 (73.2%) remained within therapeutic range for the duration of their inpatient voriconazole therapy. These findings suggest that the current practice of voriconazole TDM at our institution is yielding largely positive results, but still has room for improvement.

Teratogenic effects of voriconazole (anti-fungal drug) on Swiss albino mice

Antifungals are a class of drugs that target the treatment of invasive fungal infections. This includes polyenes, triazoles, and echinocadins. Among these, azoles are being extensively used nowadays. Triazoles have become standard for the azoles and have replaced amphotericin B as the first line of defence for fungal infections. With the increased cases of fungal infection, which affect a majority of the population at different stages and situations, one such section of the population is pregnant females. The rate and susceptibility of fungal infections are particularly higher in pregnant females, as the immunity of the mother is highly compromised. Systemic fungal infections like invasive aspergillosis, esophageal candidiasis, and candidemia are being treated with new age triazole antifungals like voriconazole. Prolonged and high concentrations of this drug are associated with various developmental anomalies. With this aim, teratogenic studies were performed on pregnant female mice during gestation and the weaning/lactation period to observe the effects of voriconazole at different dosages (8 mg/kg b.w., 10 mg/kg b.w., and 20 mg/kg b.w.). Pregnant dams were subjected to 20 mg/kg b.w. Voriconazole had a small litter size and a high number of resorptions. Craniofacial defects in the form of reduced ossification and widely open sutures, the presence of the 14th rib, asymmetry in the sternebrae, and the absence of ossified distal phalanges were some of the skeletal anomalies which were significant in the foetus and pups subjected to both 10 mg/kg b.w. and 20 mg/kg b.w. doses of voriconazole.

Retrospective evaluation of voriconazole treatment in psittacines: 14 cases (2012-2023).

To retrospectively evaluate the clinical use of voriconazole in psittacine patients for the treatment of suspected respiratory fungal infections. 14 client-owned psittacine birds. Medical records were searched from 2012 to 2023 for voriconazole use in psittacines. Species, age, clinical signs, physical examination findings, CT reports, bloodwork results, treatment, and outcome were obtained from the records or client follow-up. African grey parrots were the most prevalent species (8/14). Dyspnea (9/14) and abnormal respiratory auscultation (11/14) were the most common examination abnormalities. An initial CT was performed in all cases, and pneumonia (10/14) and air sac disease (9/14) were the most common findings, with 8 cases having both pulmonary and air sac disease. Voriconazole doses ranged from 10 to 21 mg/kg (median, 16 mg/kg), with most cases prescribed as every-12-hour frequency (12/14). Three of 14 (21%) cases died or were euthanized within 24 days of diagnosis. One case was euthanized at 311 days, and 6 cases were lost to follow-up. Four of 14 (29%) cases lived > 12 months from diagnosis. Two of these cases cleared clinical infection after receiving voriconazole at 17 to 18 mg/kg (q 12 h). No adverse effects attributable to voriconazole were reported. Voriconazole can be safely used for the treatment of suspected fungal respiratory infection in psittacines. However, the prognosis for resolution is guarded, and prolonged treatment and repeated diagnostic imaging are necessary in many cases.

Coadministration of Voriconazole and Rifabutin Can Increase the Risk of Adverse Drug Reactions in Patients with Multiple Infections.

Coinfection of tuberculosis or nontuberculous mycobacteria and Aspergillus presents a challenge in medication selection because of the pharmacokinetic interactions between rifampin and voriconazole. Some researchers have suggested the use of rifabutin as an alternative to rifampin because of its lower hepatic cytochrome P450 enzyme induction potency despite its contraindication to drug labels. This study presents clinical cases of voriconazole and rifabutin coadministration and their potential risks. This retrospective study was conducted using clinical data from patients who met the following criteria: (1) admitted to Seoul National University Hospital between July 2014 and August 2023 and (2) concurrently administered rifabutin and voriconazole for more than 5 days. Among the 6 patients analyzed, 4 experienced adverse drug reactions (ADRs). Three patients experienced visual and auditory hallucinations, lower extremity numbness, or delirious behavior. Two patients had prolonged the time from the start of the Q wave to the end of the T wave intervals, and 1 had elevated aspartate aminotransferase and alanine aminotransferase levels. In addition, 2 patients experienced severe nausea, poor oral intake, and weight loss. Despite receiving 1.81-fold the recommended voriconazole dosage, a therapeutic concentration (1.0-5.5 mg/L) was not achieved because of cytochrome P450 induction by rifabutin. However, during septic shock, the voriconazole concentration increased by 13.7- to 36-fold. Concurrent use of rifabutin and voriconazole was associated with ADRs, including the time from the start of the Q wave to the end of the T wave prolongation, hallucinations, and severe nausea. Moreover, initially, there was a significant decrease in voriconazole concentrations; however, these concentrations substantially increased during septic shock. Therefore, it is essential to monitor drug concentrations and ADRs during concurrent use of voriconazole and rifabutin.

Impact of Inflammatory Burden on Voriconazole Exposure in Oncohematological Pediatric Patients Receiving Antifungal Prophylaxis after Allogeneic HCT.

(1) Background: The impact of inflammation on voriconazole exposure in oncohematological pediatric patients represents a debated issue. We aimed to investigate the impact of serum C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) levels on voriconazole exposure in oncohematological pediatric patients requiring allogeneic hematopoietic stem cell transplantation (HCT). (2) Methods: Pediatric patients undergoing allogeneic HCT and receiving therapeutic drug monitoring (TDM)-guided voriconazole as primary antifungal prophylaxis between January 2021 and December 2023 were included. The ratio between concentration and dose (C/D) of voriconazole was used as a surrogate marker of total clearance. A receiving operating characteristic curve analysis was performed by using CRP, PCT, or IL-6 values as the test variable and voriconazole C/D ratio > 0.188 or >0.375 (corresponding to a trough concentration value [Cmin] of 3 mg/L normalized to the maintenance dose of 16 mg/kg/day in patients of age < 12 years and of 8 mg/kg/day in those ≥12 years, respectively) as the state variable. Area under the curve (AUC) and 95% confidence interval (CI) were calculated. (3) Results: Overall, 39 patients were included. The median (IQR) voriconazole Cmin was 1.7 (0.7-3.0) mg/L. A CRP value > 8.49 mg/dL (AUC = 0.72; 95%CI 0.68-0.76; p < 0.0001), a PCT value > 2.6 ng/mL (AUC = 0.71; 95%CI 0.63-0.77; p < 0.0001), and an IL-6 value > 27.9 pg/mL (AUC = 0.80; 95%CI 0.71-0.88; p < 0.0001) were significantly associated with voriconazole overexposure. Consistent results were found in patients aged <12 and ≥12 years. (4) Conclusions: A single specific threshold of inflammatory biomarkers may be linked to a significantly higher risk of voriconazole exposure in oncohematological pediatric patients after HCT, irrespective of age. Adopting a TDM-guided strategy could be useful for minimizing the risk of voriconazole overexposure.

Evaluation of Empiric Voriconazole Dosing and Therapeutic Drug Monitoring in Hospitalized Pediatric Patients.

Invasive fungal infections are a significant cause of morbidity and mortality in children with immunodeficiencies. Current dosing recommendations for voriconazole often result in subtherapeutic exposure in pediatric patients. In this single-center retrospective study, we reviewed hospitalized pediatric patients receiving voriconazole with at least one inpatient serum trough concentration measured. Patient characteristics and voriconazole dosing courses with associated trough concentrations were summarized for all patients as well as grouped by age (0 to 1 y, 2 to 11 y, and 12 to 18 y). Of 106 included patients, the median age was 9 years (range, 29 d to 18 y). Five hundred ninety courses of voriconazole were administered with 365 associated troughs. Most troughs were subtherapeutic (49%) and 30% of patients never attained a therapeutic trough. The median oral daily dose associated with a therapeutic trough was higher in younger age groups: 21.6 mg/kg 0 to 1 year, 17.9 mg/kg 2 to 11, and 9.5 mg/kg 12 to 18 years ( P <0.001). Patients younger than 2 years had the largest proportion of subtherapeutic troughs and variability in dosing. Attainment of therapeutic voriconazole concentrations was challenging across all pediatric age groups. Higher starting doses for patients younger than 2 years are likely needed.

Effectiveness and safety of the simulation-based first-dose design of voriconazole

BackgroundWe investigated whether the initial voriconazole (VRCZ) dosing design, as determined using simulation software with a population pharmacokinetic model of Japanese patients, impacts the effectiveness and safety when compared with VRCZ initiation according to the package insert. MethodsIn this single-center retrospective observational study, we employed records from Tosei General Hospital (a 633-bed hospital), dated April 2017 to September 2023. Eligible patients were divided into the software-based simulation group, comprising patients administered initial VRCZ dosage adjustment by pharmacists using software-based simulation, and the standard therapy group, whose dosage was administered by a physician following the package insert recommendations without simulation. The primary objective of this study was to determine the efficacy of VRCZ first-dose design in reducing the incidence of hepatotoxicity and visual symptoms. ResultsThe median ages of enrolled participants (n=93) were 75 (68–79) and 72 (65–78) years in the software-based simulation and standard therapy groups, respectively. Regardless of formulation, initial trough concentrations were lower in the VRCZ software-based first dosage adjustment group and higher rate within the appropriate range (1–4 μg/mL) . The incidence of all-grade hepatotoxicity or visual symptoms was significantly lower in the software-based simulation group. The log-rank test revealed a significant impact on the occurrence of ≥grade 2 hepatotoxicity in the software-based first dosage adjustment group compared to that in the standard therapy group. ConclusionsThe initial VRCZ dosing design using simulation software improved the achievement of appropriate initial trough concentrations and resulted in fewer occurrences of hepatotoxicity (≥grade 2) when compared with the standard therapy.

Associations of cumulative voriconazole dose, treatment duration, and alkaline phosphatase with voriconazole-induced periostitis

ObjectiveTo investigate the associations of cumulative voriconazole dose, treatment duration, and alkaline phosphatase with voriconazole-induced periostitis.Materials and methodsOne hundred and thirty-one patients with voriconazole use were identified using a clinical informatics tool. Health record data including age, sex, immune status, alkaline phosphatase, voriconazole levels, voriconazole dose, frequency, and treatment duration were collected. Imaging studies during the duration of treatment were reviewed by two radiology trainees and imaging features of voriconazole-induced periostitis were confirmed by a board-certified musculoskeletal radiologist. The length, location in the body, location in the bone, type, and morphology of periostitis lesions were recorded. Incident voriconazole-induced periostitis was defined as new periostitis on imaging after 28 days or more of voriconazole treatment in the absence of an alternative diagnosis. Univariate Firth’s logistic regression models were performed using cumulative voriconazole dose, treatment duration, and average ALP as predictors and incident VIP as the outcome.ResultsThere were nine patients with voriconazole-induced periostitis and 122 patients without voriconazole-induced periostitis. The most common lesion location in the body was the ribs (37%) and morphology was solid (44%). A 31.5-g increase in cumulative voriconazole dose was associated with 8% higher odds of incident periostitis. Increased treatment duration (63 days) and higher average alkaline phosphatase (50 IU/L) were associated with 7% higher odds of periostitis and 34% higher odds of periostitis, respectively.ConclusionIncreased cumulative voriconazole dose, treatment duration, and average alkaline phosphatase were associated with higher odds of voriconazole-induced periostitis.

Impact of CYP2C19, CYP2C9, CYP3A4, and FMO3 Genetic Polymorphisms and Sex on the Pharmacokinetics of Voriconazole after Single and Multiple Doses in Healthy Chinese Subjects.

Voriconazole is the first-line treatment for invasive aspergillosis. Its pharmacokinetics exhibit considerable inter- and intra-individual variability. The purpose of this study was to investigate the effects of CYP2C19, CYP2C9, CYP3A4, and FMO3 genetic polymorphisms and sex on the pharmacokinetics of voriconazole in healthy Chinese adults receiving single-dose and multiple-dose voriconazole, to provide a reference for its clinical individualized treatment. A total of 123 healthy adults were enrolled in the study, with 108 individuals and 15 individuals in the single-dose and multiple-dose doses, respectively. Plasma voriconazole concentrations were measured using a validated LC-MS/MS method, and pharmacokinetics parameters were calculated using the non-compartmental method with WinNonlin 8.2. CYP2C19, CYP2C9, CYP3A4, and FMO3 single-nucleotide polymorphisms were sequenced using the Illumina Hiseq X-Ten platform. The results suggested that CYP2C19 genetic polymorphisms significantly affected the pharmacokinetics of voriconazole at single doses of 4, 6, and 8 mg/kg and multiple doses of voriconazole. CYP3A4 rs2242480 had a significant effect on AUC0-∞ (area under the plasma concentration-time curve from time 0 to infinity) and MRT (mean residence time) of voriconazole at a single dose of 4 mg/kg in CYP2C19 extensive metabolizer. Regardless of the CYP2C19 genotype, CYP2C9 rs1057910 and FMO3 rs2266780 were not associated with the pharmacokinetics of voriconazole at three single-dose levels or multiple doses. No significant differences in most voriconazole pharmacokinetics parameters were noted between male and female participants after single and multiple dosing. For patients receiving voriconazole treatment, CYP2C19 genetic polymorphisms should be genotyped for its precision administration. In contrast, based on our study of healthy Chinese adults, it seems unnecessary to consider the effects of CYP2C9, CYP3A4, and FMO3 genetic polymorphisms on voriconazole pharmacokinetics.

Assessment of Inter-Individual Pharmacokinetic Variability of Voriconazole Based on Bile Salt Disparities using POP-PK Modeling

Background and Objectives: Voriconazole is a powerful biopharmaceutics classification system (BCS) class II antifungal agent with vast inter-individual pharmacokinetic variability. Bile salts have recently emerged as potential contributors to such variations. Based on population PK modeling and in-vitro biorelevant dissolution investigations, the current study intends to evaluate the inter-individual variability of voriconazole in pediatrics. Methods: All models were developed using PK-Sim software. A simulated population consisting of 100 pediatric individuals was established following the baseline model development. Further, experimentally obtained in-vitro dissolution data of voriconazole based on the bile salt differences representing different pediatric age groups were incorporated into a qualified pediatric model. Simulated plasma concentration-time profiles were then evaluated by comparing model-predicted parameters with that of the baseline model to draw inferences. Result: Each model was created and validated successfully. The pediatric subjects were shown to have larger inter-individual variability than adult subjects. Additionally, simulations based on individual parameter estimations from the final model showed that after administering a 4 mg/kg peroral dose of voriconazole, the anticipated Cmax values of the adult model were within a two-fold range compared to that of the pediatric model. However, upon comparison, the model-predicted population pk profiles of children, infants, and neonates showed minimal variations in the Cmax values. Conclusion: In pediatrics, voriconazole inter-individual variability was significantly influenced by the concentration of gut bile salts. Furthermore, the present research can be carried forward along with population PK modeling and sufficient clinical data for dose recommendations in special populations as well as in diseased conditions.

Mass spectrometric methods for evaluation of voriconazole avian pharmacokinetics and the inhibition of its cytochrome P450-induced metabolism

Invasive fungal aspergillosis is a leading cause of morbidity and mortality in many species including avian species such as common ravens (Corvus corax). Methods were developed for mass spectral determination of voriconazole in raven plasma as a means of determining pharmacokinetics of this antifungal agent. Without further development, GC/MS/MS (gas chromatography-tandem quadrupole mass spectrometry) proved to be inferior to LC/MS/MS (liquid chromatography-tandem quadrupole mass spectrometry) for measurement of voriconazole levels in treated raven plasma owing to numerous heat-induced breakdown products despite protection of voriconazole functional groups with trimethylsilyl moieties. LC/MS/MS measurement revealed in multi-dosing experiments that the ravens were capable of rapid or ultrarapid metabolism of voriconazole. This accounted for the animals’ inability to raise the drug into the therapeutic range regardless of dosing regimen unless cytochrome P450 (CYP) inhibitors were included. Strategic selection of CYP inhibitors showed that of four selected compounds including cimetidine, enrofloxacin and omeprazole, only ciprofloxacin (Cipro) was able to maintain voriconazole levels in the therapeutic range until the end of the dosing period. The optimal method of administration involved maintenance doses of voriconazole at 6 mg/kg and ciprofloxacin at 20 mg/kg. Higher doses of voriconazole such as 18 mg/kg were also tenable without apparent induction of toxicity. Although most species employ CYP2C19 to metabolize voriconazole, it was necessary to speculate that voriconazole might be subject to metabolism by CYP1A2 in the ravens to explain the utility of ciprofloxacin, a previously unknown enzymatic route. Finally, despite its widespread catalog of CYP inhibitions including CYP1A2 and CYP2C19, cimetidine may be inadequate at enhancing voriconazole levels owing to its known effects on raising gastric pH, a result that may limit voriconazole solubility.

Endogenous Candida endophthalmitis: diagnostics and treatment options based on case studies

Endogenous Candida endophthalmitis is an emergency that can threaten vision and the eye as awhole organ but also the life of the patient due to its systemic cause. Retrospective case evaluation of the University Hospital for Ophthalmology Halle (Saale) and the Eye Clinic of the Ernst von Bergmann Hospital Potsdam from 2017-2022. (Age, gender, side involvement, underlying diseases, symptoms, preoperative and postoperative visual acuity, diagnostics, treatment and complications). The standardized procedures for endogenous Candida endophthalmitis are explained, the data are compared with the literature and treatment suggestions are presented. 8patients with 14eyes were treated for endogenous Candida endophthalmitis. Of the patients 2 were women and 6 were men. The overall average age was 70.25 years (53-82 years), 6 patients had bilateral eye involvement and 2 patients were affected on one side. All patients had several serious immunocompromising underlying diseases that were the cause of the candidemia. All patients underwent apars plana vitrectomy (ppV) on the affected eyes except for one male patient who did not obtain permission for anesthesia. In addition to systemic treatment with antimycotics, voriconazole was routinely administered intravitreally during ppV. The patients received further intravitreal doses of voriconazole based on the findings. Vitreous body samples were taken from all patients during the ppV and detection of Candida albicans was possible in all cases. As part of the local perioperative treatment 1patient received parabulbar administration of atriamcinolone depot in both eyes, 7patients received adexamethasone depot in 11eyes and all 8patients received findings-oriented local treatment with prednisolone acetate eye drops. visual acuity increased from preoperatively 1.2logMar to 1.0logMar. Postoperative retinal detachment did not occur and there were no serious perioperative complications. 2patients died from one of the underlying diseases after 3 and 25months, respectively. Despite an increasing number of case series, there are still no uniform guidelines for ophthalmologists in Germany. There is agreement regarding systemic treatment and the intravitreal administration of antifungal agents. The role of ppV has not yet been clearly defined and the question of the adjuvant use of steroids (systemic and/or local) has also not been conclusively clarified.

Therapeutic Drug Monitoring of Voriconazole in Critically Ill Pediatric Patients: A Single-Center Retrospective Study.

Voriconazole pharmacokinetics are highly variable in pediatricpatients, and the optimal dosage has yet to be determined. The purpose of this study was to describe voriconazole pharmacokinetic and pharmacodynamic targets achieved and evaluate the efficacy and safety of voriconazole for critically ill pediatrics. This is a single-center retrospective study conducted at a pediatric intensive care unit at a tertiary/quaternary hospital. Pediatrics admitted to the pediatric intensive care unit and who received voriconazole for a proven or suspected fungal infection with at least one measured trough concentration were included. The primary outcomes included the percentage of pediatric patients who achieved the pharmacokinetic and pharmacodynamic targets. Secondary outcomes included assessing the correlation between voriconazole trough concentrations and clinical/microbiological outcomes. All statistical analyses were performed using the R statistical software and Microsoft Excel. Multiple logistic regression was used to assess the predictors of both clinical and microbiologic cures. Multiple linear regression was used to determine significant factors associated with trough concentrations. A total of 129 voriconazole trough concentrations were measured from 71 participants at steady state after at least three doses of voriconazole. The mean (± standard deviation) of the first and second trough concentrations were 2.9 (4.2) and 2.3 (3.3) mg/L, respectively. Among the first trough concentrations, only 33.8% were within the therapeutic range (1-5 mg/L), 46.5% were below the therapeutic range, and 19.7% were above the therapeutic range. A clinical cure occurred in 78% of patients, while a microbiologic cure occurred in 80% of patients. Voriconazole trough concentrations vary widely in critically ill pediatric patients and only a third of the patients achieved therapeutic concentrations with initial doses.

Enhancing voriconazole therapy in liver dysfunction: exploring administration schemes and predictive factors for trough concentration and efficacy.

Introduction: The application of voriconazole in patients with liver dysfunction lacks pharmacokinetic data. In previous study, we proposed to develop voriconazole dosing regimens for these patients according to their total bilirubin, but the regimens are based on Monte Carlo simulation and has not been further verified in clinical practice. Besides, there are few reported factors that significantly affect the efficacy of voriconazole. Methods: We collected the information of patients with liver dysfunction hospitalized in our hospital from January 2018 to May 2022 retrospectively, including their baseline information and laboratory data. We mainly evaluated the efficacy of voriconazole and the target attainment of voriconazole trough concentration. Results: A total of 157 patients with liver dysfunction were included, from whom 145 initial and 139 final voriconazole trough concentrations were measured. 60.5% (95/157) of patients experienced the adjustment of dose or frequency. The initial voriconazole trough concentrations were significantly higher than the final (mean, 4.47 versus 3.90μg/mL, p = 0.0297). Furthermore, daily dose, direct bilirubin, lymphocyte counts and percentage, platelet, blood urea nitrogen and creatinine seven covariates were identified as the factors significantly affect the voriconazole trough concentration. Binary logistic regression analysis revealed that the lymphocyte percentage significantly affected the efficacy of voriconazole (OR 1.138, 95% CI 1.016-1.273), which was further validated by the receiver operating characteristic curve. Conclusion: The significant variation in voriconazole trough concentrations observed in patients with liver dysfunction necessitates caution when prescribing this drug. Clinicians should consider the identified factors, particularly lymphocyte percentage, when dosing voriconazole in this population.

Nomogram for the prediction of tigecycline-induced hypofibrinogenaemia in a Chinese population

Tigecycline has been widely used for multi-drug-resistant bacterial infections in China. Although many studies have reported the risk factors for tigecycline-induced hypofibrinogenaemia, it remains unknown whether valproic acid or voriconazole in combination with tigecycline is associated with the decrease in fibrinogen, as both drugs could lead to coagulation disorders. The aim of this study was to develop a nomogram for the prediction of tigecycline-induced hypofibrinogenaemia. This was a multi-centre retrospective case-control study. The primary outcome was the accurate prediction of tigecycline-induced hypofibrinogenaemia. Nomograms were developed from logistic regression models with least absolute shrinkage and selection operator regression for variable selection. Model performance was assessed via calibration plots, and models were validated internally using bootstrapping on a validation cohort. In total, 2362 patients were screened, of which 611 were eligible for inclusion in this study. These 611 patients were divided into the training cohort (n=488) and the validation cohort (n=123). Predictors included in the nomogram for the total population were total dose, age, fibrinogen, prothrombin time (PT), comorbidity, and concomitant use of voriconazole. Total dose, fibrinogen, PT, activated partial thromboplastin time, white blood cell count, and concomitant use of voriconazole were selected to predict hypofibrinogenaemia in patients with malignant haematologic diseases. Both models were calibrated adequately, and their predictions were correlated with the observed outcome. The cut-offs for treatment duration in the total population and the subgroup were 10 and 6 days, respectively. Tigecycline in combination with voriconazole could increase the risk of hypofibrinogenaemia, and tigecycline-induced hypofibrinogenaemia is more likely to occur in patients with malignant haematologic diseases.

Trends in Implementation of Loading Dose of Voriconazole from 2010 to 2019 and Influencing Factors of Loading Dose Based on a Japanese Administrative Claim Database: A Retrospective Cohort Study.

A loading dose of voriconazole (VRCZ) is recommended to increase its blood concentration at an early stage. However, the trends in the implementation of the loading dose in VRCZ in Japan has not yet been clarified. In addition, although pharmacists play many important roles in antimicrobial stewardship, the effect of pharmacist intervention on the implementation of a loading dose of VRCZ has not yet been reported. Therefore, this study aimed to clarify the implementation of loading dose of VRCZ and the influencing factors of loading dose. This study used an administrative claims database that included patients who received injectable VRCZ between 2010 and 2019. The implementation of loading doses in the VRCZ was evaluated annually. Multivariate logistic regression analysis was performed to identify the factors influencing loading dose. Overall, 2197 patients were included. The implementation rate of the loading dose remained below 65% throughout the study period. Among medical fees that can be calculated through pharmacist intervention, only the infection prevention and control premium significantly increased the implementation of loading dose of VRCZ (odds ratio: 1.587, 95% confidence interval: 1.053-2.392). In conclusion, antifungal stewardship may have been promoted at medical institutions that established infection prevention and control. In the future, pharmacists will need to intervene more actively from the beginning of VRCZ administration.

Voriconazole-induced visual abnormality based on drug interaction between voriconazole and esomeprazole: A case report.

We report a case of voriconazole-induced visual abnormality based on drug interaction of voriconazole and esomeprazole, therapeutic drug monitoring, and optimal therapy. An 81-year-old male developed visual abnormality after the blood concentration of voriconazole was up to 6.47 mg/L induced by coadministration with esomeprazole. Voriconazole is a substrate of multiple CYP450 isoenzymes including CYP2C19 (the major route), CYP3A4, and CYP2C9. Esomeprazole, a proton pump inhibitor (PPI), is also converted to inactive metabolites through CYP3A4 and CYP2C19-mediated metabolism, and is also a CYP2C19 inhibitor. The coadministration with esomeprazole inhibited the metabolism of voriconazole via CYP2C19 and promoted the elevation of voriconazole blood concentration beyond the minimum toxic level (5.5mg/L). According to the pharmacist's advice, the adverse effects of visual abnormalities in the patient disappeared after the clinician reduced voriconazole dosage by 50% when other medication schedules remained unchanged. Therefore, therapeutic drug monitoring of voriconazole should be considered in patients receiving PPIs, especially esomeprazole, in order to adjust the dosage in time and achieve optimal therapeutic response and minimal adverse reaction.

Therapeutic Drug Monitoring of Voriconazole in Patients with End-Stage Liver Disease.

This study aimed to identify the factors that influence voriconazole (VCZ) plasma concentrations and optimize the doses of VCZ in patients with end-stage liver disease (ESLD). Patients with ESLD who received a VCZ maintenance dose of 100 mg twice daily (group A, n = 57) or the VCZ maintenance dose of 50 mg twice daily (group B, n = 37), orally or intravenously, were enrolled in this study. Trough plasma concentrations (Cmin) of VCZ between 1 and 5 mg/L were considered within the therapeutic target range. The VCZ Cmin was determined in 94 patients with ESLD. The VCZ Cmin of patients in group A was remarkably higher than those in group B (4.85 ± 2.53 mg/L vs 2.75 ± 1.40 mg/L; P < 0.001). Compared with group A, fewer patients in group B had VCZ Cmin outside the therapeutic target (23/57 vs. 6/37, P = 0.021). Univariate and multivariate analyses suggested that both body weight and Model for End-Stage Liver Disease scores were closely associated with the VCZ Cmin in group B. These data indicate that dose optimization based on body weight and Model for End-Stage Liver Disease scores is required to strike an efficacy-safety balance during VCZ treatment in patients with ESLD.