Interaction of age and CYP2C19 genotypes on voriconazole steady-state trough concentration in Chinese patients.

OBJECTIVES: Both age and CYP2C19 genotypes affect voriconazole plasma concentration; the interaction of age and CYP2C19 genotypes on voriconazole plasma concentration remains unknown. This study aims to investigate the combined effects of age and CYP2C19 genotypes on voriconazole plasma concentration in Chinese patients. METHODS: A total of 480 patients who received voriconazole treatment were recruited. CYP2C19*2 (rs4244285) and CYP2C19*3 (rs4986893) polymorphisms were genotyped. Patients were divided into the young and the elderly groups by age of 60 years old. Influence of CYP2C19 genotype on steady-state trough concentration (C ss-min ) in overall patients and in age subgroups was analyzed. RESULTS: Voriconazole C ss-min correlated positively with age, and mean voriconazole C ss-min was significantly higher in the elderly group ( P  < 0.001). CYP2C19 poor metabolizers showed significantly increased mean voriconazole C ss-min in the young but not the elderly group. The percentage of patients with subtherapeutic voriconazole C ss-min (<1.0 mg/l) was higher in the young group and that of supratherapeutic voriconazole C ss-min (>5.5 mg/l) was higher in the elderly patients. When the average C ss-min in the CYP2C19 normal metabolizer genotype was regarded as a reference, CYP2C19 genotypes showed greater impact on voriconazole C ss-min in the young group, while the influence of age on voriconazole C ss-min exceeded CYP2C19 genotypes in the elderly. CONCLUSION: CYP2C19 genotypes affects voriconazole exposure is age dependent. Influence of CYP2C19 poor metabolizer genotype on increased voriconazoleexposure is prominent in the young, while age is a more important determinant factor for increased voriconazole exposure in the elderly patients.

Plasma itraconazole concentrations during treatment of feline sporotrichosis.

Itraconazole (ITZ) is the most used drug to treat feline sporotrichosis; however, little is known about its pharmacokinetics in cats with this mycosis. The aim of this study was to determine plasma ITZ concentrations in cats with sporotrichosis treated with ITZ as monotherapy or in combination with potassium iodide (KI). Cats diagnosed with sporotrichosis received orally ITZ (100 mg/cat/day) or combination therapy with ITZ (100 mg/cat/day) and KI (2.5-5 mg/kg/day) in the case of worsening or stagnation of the clinical condition. At each monthly visit, blood samples were collected at an interval of 4 h for analysis of trough and peak plasma ITZ concentrations by HPLC. Clinical features and laboratory parameters were evaluated during follow-up. Sixteen cats were included in the study. The median plasma ITZ concentration of all cats was 0.75 µg/mL. The median plasma ITZ concentration was 0.5 µg/mL in cats that received ITZ monotherapy (n = 12) and 1.0 µg/mL in those treated with ITZ + KI (n = 4). The clinical cure rate was 56.3% (n = 9) and the median treatment duration was 8 weeks. Nine cats (56.3%) developed adverse clinical reactions, and hyporexia was the most frequent (n = 8; 88.9%). Serum alanine aminotransferase was elevated in four cats (25%). The median plasma ITZ concentration detected in cats was considered to be therapeutic (>0.5 µg/mL) and was reached after 4 weeks of treatment. Plasma ITZ concentrations were higher in cats that received ITZ + KI compared to those treated only with ITZ, suggesting pharmacokinetic synergism between these drugs.

Itraconazole is the most common therapy for feline sporotrichosis, and combination therapy with potassium iodide is used in nonresponsive cases. Our study showed that all cats achieved a therapeutic plasma concentration of itraconazole, with higher levels in cats treated with the combination therapy.

Factors Influencing Serum Posaconazole Concentrations in Patients With Hematologic Malignancies Receiving Delayed-Release Tablets.

BACKGROUND: Posaconazole (PCZ) plays a crucial role in the prophylaxis and treatment of invasive fungal infections in hematologic malignancies. PCZ concentrations reportedly vary among patients receiving delayed-release tablets (DRT). However, the factors influencing these concentrations remain insufficiently elucidated. Therefore, this study aimed to evaluate the factors influencing PCZ concentrations and their effect on the probability of target attainment (PTA) using a population pharmacokinetic (PPK) approach. We also explored the relationship between PCZ exposure and hepatotoxicity. METHODS: This retrospective study included adult patients with hematologic malignancies who received PCZ DRT. A PPK model was developed based on observational data for 130 concentrations in 28 patients. Simulation analyses were performed to assess the PTA at standard doses of 0.7 and 1.0 mg/L for prophylaxis and treatment, respectively. Estimated concentrations were used to evaluate the correlation between PCZ exposure and hepatotoxicity. RESULTS: Significant factors influencing PCZ concentrations included body weight, serum total protein levels, and diarrhea. Diarrhea correlated with decreased PCZ concentrations resulting in up to 26% lower PTA compared with that without diarrhea. Moreover, PTA declined markedly as the total protein levels decreased from 6.6 g/dL to 4.4 g/dL. The incidence of hepatotoxicity was 17.4% (4/23); no significant relationship could be established between the PCZ concentrations and hepatotoxicity ( P = 0.188). CONCLUSIONS: We identified the factors affecting PCZ exposure, which could not be detected by PPK analysis using data from clinical trials. Our results suggest that the generally recommended dose of PCZ causes underexposure in patients with hematologic malignancies characterized by high body weight, hypoproteinemia, or concurrent diarrhea. Therapeutic drug monitoring for DRT may be recommended, especially in patients with these risk factors.

Association of procalcitonin with voriconazole concentrations: a retrospective cohort study.

Inflammation is a potential risk factor of voriconazole (VCZ) overdose, procalcitonin (PCT) is reported to act as a diagnostic marker for bacterial infections. However, the association of PCT with VCZ trough serum concentrations (VCZ-Cmin) is not fully clear. Our study aims to investigate the associations between PCT and VCZ-Cmin. In this retrospective cohort study, we collected the clinical data of 147 patients who received VCZ and monitored the VCZ concentration of them in our hospital from August 2017 to August 2021. All patients underwent routine clinical examinations on the day or the day before VCZ administration. General information and clinical symptoms of these patients were recorded. Multivariate liner analysis showed that PCT was significantly associated with VCZ-Cmin (p < 0.001). Overall, it was shown that VCZ-Cmin was significantly increased by 0.32 µg/mL for each fold increment in PCT in crude model. In the minor adjusted model (Model 1, adjustment for sex, age, albumin, direct bi1irubin, WBC) and fully adjusted model (Model 2, adjustment for sex, age, albumin, direct bilirubin, WBC, AST and ALT), VCZ-Cmin was significantly increased by 0.23 µg/mL and 0.21 µg/mL, respectively, for each fold increment in PCT. In conclusion, this research reveals the correlation between PCT and VCZ-Cmin, indicating that PCT has the potential to serve as a valuable biomarker for drug monitoring in the treatment of VCZ.

Pharmacokinetics of intraarticular liposomal amphotericin B in goats (Capra aegagrus hircus).

Lameness is a significant welfare concern in goats. Amphotericin B is used via intraarticular (IA) administration in models to study experimentally induced lameness in large animals. The main objective of this study was to estimate plasma pharmacokinetic (PK) parameters for amphotericin B in goats after a single IA administration. Liposomal amphotericin B was administered to ten Kiko-cross goats at a dose of 10 mg total (range: 0.34-0.51 mg/kg) via IA administration into the right hind lateral distal interphalangeal joint. Plasma samples were collected over 96 h. Amphotericin B concentrations were measured via liquid chromatography/mass spectrometry (LC-MS/MS). A non-compartmental analysis was used to derive PK parameters. Following single IA administration, maximum plasma concentration was estimated at 54.6 ± 16.5 ng/mL, and time to maximum concentration ranged from 6 to 12 h. Elimination half-life was estimated at 30.9 ± 16.5 h, and mean residence time was 45.1 ± 10.4 h. The volume of distribution after IA administration was 13.3 ± 9.4 L/kg. The area under the curve was 1481 ± 761 h*ng/mL. The achieved maximum concentration was less than the observed concentrations for other species and routes of administration. Further research is needed into the pharmacodynamics of IA liposomal amphotericin B in goats to determine specific research strategies.

Development, optimization and validation of an analytical method for the determination of voriconazole in plasma by high-performance liquid chromatography-ultraviolet detection: Application for comprehensive study.

OBJECTIVES: Voriconazole is a widely used antifungal agent in clinical settings. However, its use has been associated with neurological side effects in some patients. For this reason, it is crucial to monitor its plasma levels to ensure that they are within the therapeutic range. Thus, in this study, we aimed to develop a simple, fast, and efficient method for the determination of voriconazole in plasma using reversed-phase HPLC-UV. We also aimed to validate the method for its application to routine analysis of immunocompromised patients. MATERIAL AND METHODS: Plasma samples from immunocompromised patients were subjected to deproteinization with acetonitrile followed by centrifugation. Chromatographic separation was carried out on a C18 column with UV detection at 254nm in isocratic mode. The concentrations were calculated by comparing peak areas to those of the internal standard, ketoconazole. The method was validated using the accuracy profile, which uses a calibration curve established for the therapeutic range of 1 to 5.5µg/mL. RESULTS: The developed method was proved to be rapid by giving a short analysis time for voriconazole at around 5.5min. Additionally, no interference with the biological matrix was detected. The obtained recoveries were higher than 90%. The accuracy profile showed that the method was accurate and precise for the determination of voriconazole in plasma. CONCLUSION: The developed method was proved to be simple, efficient, that requires minimal sample preparation. Thus, it can be routinely applied for the therapeutic monitoring of voriconazole.

Human-relevant concentrations of the antifungal drug clotrimazole disrupt maternal and fetal steroid hormone profiles in rats.

Clotrimazole is a non-prescription and broad-spectrum antifungal drug sold under brand names such as Canesten® and Lotrimin®. It is used to treat different types of fungal infections, from oral thrush to athlete's foot and vaginal mycosis. The level of exposure to clotrimazole is uncertain, as the exact usage amongst self-medicating patients is unclear. Recent studies have raised potential concern about the unsupervised use of clotrimazole during pregnancy, especially since it is a potent inhibitor of CYP enzymes of the steroidogenesis pathway. To address some of these concerns, we have assessed the effects of intrauterine exposure to clotrimazole on developing rat fetuses. By exposing pregnant rats to clotrimazole 25 or 75 mg/kg bw/day during gestation days 7-21, we obtained internal fetal concentrations close to those observed in humans. These in vivo data are in strong agreement with our physiologically-based pharmacokinetic (PBK)-modelled levels. At these doses, we observed no obvious morphological changes to the reproductive system, nor shorter male anogenital distance; a well-established morphometric marker for anti-androgenic effects in male offspring. However, steroid hormone profiles were significantly affected in both maternal and fetal plasma, in particular pronounced suppression of estrogens was seen. In fetal testes, marked up-concentration of hydroxyprogesterone was observed, which indicates a specific action on steroidogenesis. Since systemic clotrimazole is rapidly metabolized in humans, relevant exposure levels may not in itself cause adverse changes to the reproductive systems. Its capacity to significantly alter steroid hormone concentrations, however, suggests that clotrimazole should be used with caution during pregnancy.

Effect of Therapeutic Drug Monitoring and Cytochrome P450 2C19 Genotyping on Clinical Outcomes of Voriconazole: A Systematic Review.

OBJECTIVES: To examine current knowledge on the clinical utility of therapeutic drug monitoring (TDM) in voriconazole therapy, the impact of CYP2C19 genotype on voriconazole plasma concentrations, and the role of CYP2C19 genotyping in voriconazole therapy. DATA SOURCES: Three literature searches were conducted for original reports on (1) TDM and voriconazole outcomes and (2) voriconazole and CYP2C19 polymorphisms. Searches were conducted through EMBASE, MEDLINE/PubMed, Scopus, and Cochrane Central Register of Controlled Trials from inception to June 2020. STUDY SELECTION AND DATA EXTRACTION: Randomized controlled trials, cohort studies, and case series with ≥10 patients were included. Only full-text references in English were eligible. DATA SYNTHESIS: A total of 63 studies were reviewed. TDM was recommended because of established concentration and efficacy/toxicity relationships. Voriconazole trough concentrations ≥1.0 mg/L were associated with treatment success; supratherapeutic concentrations were associated with increased neurotoxicity; and hepatotoxicity associations were more prevalent in Asian populations. CYP2C19 polymorphisms significantly affect voriconazole metabolism, but no relationship with efficacy/safety were found. Genotype-guided dosing with TDM was reported to increase chances of achieving therapeutic range. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Genotype-guided dosing with TDM is a potential solution to optimizing voriconazole efficacy while avoiding treatment failures and common toxicities. CONCLUSIONS: Voriconazole plasma concentrations and TDM are treatment outcome predictors, but research is needed to form a consensus target therapeutic range and dosage adjustment guidelines based on plasma concentrations. CYP2C19 polymorphisms are a predictor of voriconazole concentrations and metabolism, but clinical implications are not established. Large-scale, high-methodological-quality trials are required to investigate the role for prospective genotyping and establish CYP2C19-guided voriconazole dosing recommendations.

Predictive Value of FMO3 Variants on Plasma Disposition and Adverse Reactions of Oral Voriconazole in Febrile Neutropenia.

BACKGROUND AND OBJECTIVES: With the increasing number of patients with febrile neutropenia (FN), voriconazole (VRC) has been widely used in hospitals for first-line treatment of FN. The study was designed for evaluating the influence of FMO3 mutation on the plasma disposition and adverse reactions of VRC in FN. MATERIALS AND METHODS: A single-center observational study was conducted in the inpatient ward for 4 years. The genotypes of FMO3 and cytochrome P450 (CYP) 2C19 were detected by PCR-restriction fragment length polymorphism. Patients with neutropenia were screened according to the CYP2C19 metabolic phenotype and other inclusion criteria. Five days after empirical administration of VRC, blood concentrations of VRC and nitrogen oxides in patients' blood were determined by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI MS/MS). Serum parameters and clinical adverse reaction symptoms in the medical records were collected and statistically analyzed. RESULTS: A total of 165 patients with neutropenia with the intermediate metabolic phenotype of CYP2C19 were screened. At the initial stage of oral VRC treatment, patients with the FMO3 E308G genotype had a poorer plasma disposal ability to VRC than those with the wide type of FMO3 (WT) genotype (p = 0.0005). Moreover, patients with the FMO3 E308G genotype were more likely to have adverse drug reactions and abnormal serum parameters after receiving VRC treatment. For example, the serum potassium level in the FMO3 E308G genotype group was significantly lower than that in the WT group (p = 0.028), the abnormal level of total bilirubin in the FMO3 E308G genotype group was significantly higher than that in the WT group (p = 0.049), and the aspartate aminotransferase level in the E308G group was significantly higher than that in the WT group (p = 0.05). The incidence of atopic dermatitis and visual impairment in the FMO3 E308G genotype group was 67 and 75%, respectively, and the incidences of peripheral neuroedema, headache, and diarrhea were 57, 50, and 60%, respectively, which were significantly different from those in the WT group. CONCLUSION: FMO3 E308G reduces the activity of the FMO3 enzyme by decreasing the metabolic ability of VRC, which increases the plasma concentration of VRC and may also lead to adverse reactions in patients with FN.

Potential voriconazole associated posterior reversible leukoencephalopathy in children with malignancies: Report of two cases.

INTRODUCTION: The fungal infection has become severe morbidity amongst patients with malignancy. Voriconazole, a new generation of triazole, has shown excellent results in treating invasive fungal infections. CASE REPORT: Herein, we report two cases of posterior reversible encephalopathy syndrome (PRES), which induced after voriconazole exposure.Management and outcome: Magnetic resonance imaging, and the serum level of voriconazole were investigated in both patients to assess toxicity. The role of methotrexate, as one of the possible causes of PRES, is weakened significantly through precise assessing diffusion-weighted images on magnetic resonance imaging. DISCUSSION: These unique cases emphasize that voriconazole can induce PRES even at therapeutic levels. Therefore, in the case of neurotoxicity, PRES must be considered, and voriconazole should discontinue. The prognosis seemed promising when voriconazole stopped immediately after clinical suspicion.

Influence of switching from intravenous to oral administration on serum voriconazole concentration.

WHAT IS KNOWN AND OBJECTIVE: While bioavailability of oral voriconazole is known to be >90%, several reports have observed much lower oral bioavailability. The aim of the present study was to assess the oral bioavailability of voriconazole in clinical use by evaluating the change in serum voriconazole concentration in patients who received intravenous-to-oral switch therapy with the same dose of voriconazole. METHODS: A single-centre, retrospective cohort study was conducted at the 614-bed Gifu University Hospital in Japan. Patients who received intravenous-to-oral switch therapy with the same dose of voriconazole between 1 January 2011 and 31 December 2018 were enrolled in the present study. We evaluated changes in serum voriconazole concentration before and after switch therapy. RESULTS: Voriconazole trough concentrations significantly decreased following oral compared to intravenous treatment (2.5 ± 1.5 µg/mL vs 3.3 ± 2.0 µg/mL, p = 0.021). The median change rate of serum concentration by switching the route of administration was 82.7%, with wide inter-individual variability (range 27.2-333.3%). Further, concomitant glucocorticoid administration was a significant protective factor for reducing serum concentration (OR 0.16, 95% CI 0.03-0.79, p = 0.025). WHAT IS NEW AND CONCLUSION: Switching from intravenous to oral treatment resulted in a significant decline in voriconazole trough concentrations with wide inter-individual variability. Therefore, measurement of serum concentration for dose adjustment should be performed after switching to the oral form.

Characterization of Isavuconazole serum concentrations after enteral feeding tube administration in a hospitalized cohort: A case series.

WHAT IS KNOWN AND OBJECTIVE: Invasive fungal infections often occur in patients with comorbidities that complicate oral administration. Serum concentrations of isavuconazole were characterized after enteral tube administration. CASE DESCRIPTION: Thirteen of 14 isavuconazole concentrations were >1 mg/dl (median 1.6 mg/dl) among those receiving enteral tube administration, which was comparable to intravenous (median 1.9 mg/dl). Higher concentrations were observed during oral administration (median 3 mg/dl). WHAT IS NEW AND CONCLUSION: Administration of isavuconazole via tube resulted in concentrations comparable to FDA-approved routes of administration. This route may be feasible and appropriate for select patients.

Simultaneous analysis of drugs administered to lung-transplanted patients using liquid chromatography-tandem mass spectrometry for therapeutic drug monitoring.

Several drugs are administered to lung-transplanted patients, which are monitored using therapeutic drug monitoring (TDM). Therefore, we developed and validated a liquid chromatography-tandem mass spectrometry method to simultaneously analyze immunosuppressive drugs such as mycophenolic acid, antifungal drugs such as voriconazole and itraconazole, and its metabolite hydroxyitraconazole. Chromatographic separation was achieved using a C18 column and gradient flow of mobile phase comprising 20 mM aqueous ammonium formate and 20 mM ammonium formate-methanol solution. A simple protein precipitation treatment was performed using acetonitrile/methanol and mycophenolic acid-2 H3 , voriconazole-2 H3 , itraconazole-2 H4 , and hydroxyitraconazole-2 H4 as internal standards. The linearity ranges of mycophenolic acid, voriconazole, itraconazole, and hydroxyitraconazole were 100-20,000, 50-10,000, 5-1000, and 5-1000 ng/mL, respectively. The retention time of each target was less than 2 min. The relative errors in intra- and inter-day were within ±7.6%, the coefficient of variation was 8.9% or less for quality control low, medium, and high, and it was 15.8% or less for lower limit of quantitation. Moreover, the patient samples were successfully quantified, and they were within the linear range of measurements. Therefore, our new method may be useful for TDM in lung-transplanted patients.

Electrocatalytic evaluation of graphene oxide warped tetragonal t-lanthanum vanadate (GO@LaVO4) nanocomposites for the voltammetric detection of antifungal and antiprotozoal drug (clioquinol).

Metastable and rarely reported GO warped tetragonal phase t-lanthanum vanadate nanocomposites (GO@LaVO4-NCs) are reported for the sensitive electrochemical determination of antifungal drug Clioquinol (CQ). The hydrothermal method was adopted for synthesis of GO@LaVO4-NCs. The electrochemical performance of CQ was examined using cyclic voltammetry (CV) and differential plus voltammetry (DPV) at GO@LaVO4-NCs modified glassy carbon electrode (GCE). The electrocatalytic oxidation of CQ at the GO@LaVO4-NCs/GCE shows the highest anodic peak current at a potential of +0.51 V vs. Ag/AgCl. The proposed sensor provides excellent sensitivity of 4.1894 µA µM-1 cm-2, a very low detection limit (LOD) of 2.44 nM, and a wide range of 25 nM to 438.52 µM towards CQ detection. Finally, the detection of CQ in biological media was successfully done using the GO@LaVO4-NCs/GCE and possesses recoveries of 94.67-98.0%.

Application of Design of Experiments® Approach-Driven Artificial Intelligence and Machine Learning for Systematic Optimization of Reverse Phase High Performance Liquid Chromatography Method to Analyze Simultaneously Two Drugs (Cyclosporin A and Etodolac) in Solution, Human Plasma, Nanocapsules, and Emulsions.

The objectives of current investigation are (1) to find out wavelength of maximum absorbance (λmax) for combined cyclosporin A and etodolac solution followed by selection of mobile phase suitable for the RP-HPLC method, (2) to define analytical target profile and critical analytical attributes (CAAs) for the analytical quality by design, (3) to screen critical method parameters with the help of full factorial design followed by optimization with face-centered central composite design (CCD) approach-driven artificial neural network (ANN)-linked with the Levenberg-Marquardt (LM) algorithm for finding the RP-HPLC conditions, (4) to perform validation of analytical procedures (trueness, linearity, precision, robustness, specificity and sensitivity) using combined drug solution, and (5) to determine drug entrapment efficiency value in dual drug-loaded nanocapsules/emulsions, percentage recovery value in human plasma spiked with two drugs and solution state stability analysis at different stress conditions for substantiating the double-stage systematically optimized RP-HPLC method conditions. Through isobestic point and scouting step, 205 nm and ACN:H2O mixture (74:26) were selected respectively as the λmax and mobile phase. The ANN topology (3:10:4) indicating the input, hidden and output layers were generated by taking the 20 trials produced from the face-centered CCD model. The ANN-linked LM model produced minimal differences between predicted and observed values of output parameters (or CAAs), low mean squared error and higher correlation coefficient values in comparison to the respective values produced by face-centered CCD model. The optimized RP-HPLC method could be applied to analyze two drugs concurrently in different formulations, human plasma and solution state stability checking.

TERBINAFINE PHARMACOKINETICS FOLLOWING SINGLE-DOSE ORAL ADMINISTRATION IN RED-EARED SLIDER TURTLES (TRACHEMYS SCRIPTA ELEGANS): A PILOT STUDY.

In this pilot study, the pharmacokinetics of terbinafine were determined in six apparently healthy red-eared slider turtles (Trachemys scripta elegans) after a single PO administration. Terbinafine suspension (15 mg/kg, once) was administered via gavage tube to all turtles. Blood samples were collected immediately before (time 0) and at 1, 2, 4, 8, 24, and 48 h after drug administration. Plasma terbinafine concentrations were quantified by ultra-performance liquid chromatography-mass spectrometry, and noncompartmental pharmacokinetic analysis was performed. None of the animals showed any adverse responses following terbinafine administration. Mean area under the curve from time 0 to 24 h was 1,213 h × ng/ml (range 319-7,309), mean peak plasma concentration was 201.5 ng/ml (range 45.8-585.3), mean time to maximum plasma concentration was 1.26 h (range 1-4), mean residence time was 7.71 h (range 3.85-14.8), and mean terminal half-life was 5.35 h (range 2.67-9.83). The administration of terbinafine (15 mg/kg, PO) may be appropriate for treatment of select fungal organisms with low minimum inhibitory concentrations in red-eared slider turtles but may require q12h administration even for organisms with low minimum inhibitory concentrations. Multiple-dose studies as well as clinical studies are needed to determine ideal dosages and efficacy.

PLASMA VORICONAZOLE CONCENTRATIONS FOLLOWING SINGLE- AND MULTIPLE-DOSE SUBCUTANEOUS INJECTIONS IN WESTERN POND TURTLES (ACTINEMYS MARMORATA).

A recently characterized fungal pathogen, Emydomyces testavorans, has been associated with ulcerative shell disease and significant morbidity in Western pond turtles. Voriconazole is a second-generation triazole antifungal medication that prevents fungal growth through disruption of ergosterol synthesis, causing abnormalities in the fungal cell membrane. Preliminary reports of minimum inhibitory concentrations (MIC) indicate that voriconazole is effective in vitro against E. testavorans. Ultraperformance liquid chromatography was used to measure voriconazole plasma concentrations in blood samples from healthy Western pond turtles after administration of a single SC injection of 10 mg/kg and after multiple doses (10 mg/kg SC q48h for seven doses). The data were analyzed using a naïve pooled approach. Mean (SE) observed time to maximum concentration was 2 (0.18) h for a single dose and 50 (2.2) h for multiple doses; the multiple-dose trial observed mean (SE) maximum concentration was 12.4 (2.2) µg/ml, and observed mean (SE) trough concentration was 1.7 (0.7) µg/ml. Multifocal skin sloughing following the single-dose trial was observed in one turtle and there was a significant increase in polychromatophilic cells amongst the study turtles after the multiple-dose voriconazole trial. No other adverse effects were observed. When voriconazole was administered at 10 mg/kg SC q48h, observed trough plasma concentrations were consistently higher than reported E. testavorans MIC concentrations. Further study is needed to determine the clinical safety and in vivo efficacy of this dose in Western pond turtles.

EFFICACY OF SUBCUTANEOUS IMPLANTS TO PROVIDE CONTINUOUS PLASMA TERBINAFINE IN HELLBENDERS (CRYPTOBRANCHUS ALLEGANIENSI) FOR FUTURE PROPHYLACTIC USE AGAINST CHYTRIDIOMYCOSIS.

Batrachochytrium dendrobatidis (Bd) is an important fungal pathogen present in wild hellbender (Cryptobranchus alleganiensis) populations that appears to cause disease during novel exposure and acute stress. Hellbender repatriation efforts are ongoing to combat declining populations, but mortality by chytridiomycosis (disease from Bd) after release has been reported. The goal was to determine whether a safe antifungal agent could be administered and provide prolonged plasma concentrations without repeated handling. A subcutaneous implant impregnated with 24.5 mg of terbinafine was tested in three juvenile eastern hellbenders (C. a. alleganiensis) raised in human care, and plasma terbinafine concentrations were recorded from weekly to biweekly for 141 days. Plasma concentrations were variable, with peak plasma concentrations of 1,610, 112, and 66 ng/ml between 28 and 56 days postimplant. Although all hellbenders achieved plasma concentrations above the published minimum inhibitory concentration for terbinafine against Bd zoospores (63 ng/ml) at several time points, only one individual remained above this threshold for more than two consecutive time intervals. Results show the potential for these implants as a prophylaxis for chytridiomycosis in captive-to-wild hellbender releases. However, further investigation will be needed to determine the plasma concentrations required to achieve prophylaxis in vivo and implant reliability.

A Case Series and Literature Review of Isavuconazole Use in Pediatric Patients with Hemato-oncologic Diseases and Hematopoietic Stem Cell Transplantation.

We analyzed the use of isavuconazole (ISA) as treatment or prophylaxis for invasive fungal disease (IFD) in children with hemato-oncologic diseases. A multicentric retrospective analysis was performed among centers belonging to the Italian Association for Pediatric Hematology and Oncology (AIEOP). Pharmacokinetic (PK) monitoring was applied by a high-performance liquid chromatography-tandem mass spectrometry (HLPC-MS/MS) assay. Twenty-nine patients were studied: 10 during chemotherapy and 19 after allogeneic hematopoietic stem cell transplantation (HSCT). The patients consisted of 20 males and 9 females with a median age of 14.5 years (age range, 3 to 18 years) and a median body weight of 47 kg (body weight range, 15 to 80 kg). ISA was used as prophylaxis in 5 patients and as treatment in 24 cases (20 after therapeutic failure, 4 as first-line therapy). According to European Organization for Research and Treatment of Cancer (EORTC) criteria, we registered 5 patients with proven IFD, 9 patients with probable IFD, and 10 patients with possible IFD. Patients with a body weight of <30 kg received half the ISA dose; the others received ISA on the adult schedule (a 200-mg loading dose every 8 h on days 1 and 2 and a 200-mg/day maintenance dose); for all but 10 patients, the route of administration switched from the intravenous route to the oral route during treatment. ISA was administered for a median of 75.5 days (range, 6 to 523 days). The overall response rate was 70.8%; 12 patients with IFD achieved complete remission, 5 achieved partial remission, 5 achieved progression, and 3 achieved stable IFD. No breakthrough infections were registered. PK monitoring of 17 patients revealed a median ISA steady-state trough concentration of 4.91 mg/liter (range, 2.15 to 8.54 mg/liter) and a concentration/dose (in kilograms) ratio of 1.13 (range, 0.47 to 3.42). Determination of the 12-h PK profile was performed in 6 cases. The median area under the concentration-time curve from 0 to 12 h was 153.16 mg·h/liter (range, 86.31 to 169.45 mg·h/liter). Common Terminology Criteria for Adverse Events grade 1 to 3 toxicity (increased transaminase and/or creatinine levels) was observed in 6 patients, with no drug-drug interactions being seen in patients receiving immunosuppressants. Isavuconazole may be useful and safe in children with hemato-oncologic diseases, even in the HSCT setting. Prospective studies are warranted.

Fosmanogepix (APX001) Is Effective in the Treatment of Immunocompromised Mice Infected with Invasive Pulmonary Scedosporiosis or Disseminated Fusariosis.

There are limited treatment options for immunosuppressed patients with lethal invasive fungal infections due to Fusarium and Scedosporium Manogepix (MGX; APX001A) is a novel antifungal that targets the conserved Gwt1 enzyme required for localization of glycosylphosphatidylinositol-anchored mannoproteins in fungi. We evaluated the in vitro activity of MGX and the efficacy of the prodrug fosmanogepix (APX001) in immunosuppressed murine models of hematogenously disseminated fusariosis and pulmonary scedosporiosis. The MGX minimum effective concentration (MEC) for Scedosporium isolates was 0.03 µg/ml and ranged from 0.015 to 0.03 µg/ml for Fusarium isolates. In the scedosporiosis model, treatment of mice with 78 mg/kg and 104 mg/kg of body weight fosmanogepix, along with 1-aminobenzotriazole (ABT) to enhance the serum half-life of MGX, significantly increased median survival time versus placebo from 7 days to 13 and 11 days, respectively. Furthermore, administration of 104 mg/kg fosmanogepix resulted in an ∼2-log10 reduction in lung, kidney, or brain conidial equivalents/gram tissue (CE). Similarly, in the fusariosis model, 78 mg/kg and 104 mg/kg fosmanogepix plus ABT enhanced median survival time from 7 days to 12 and 10 days, respectively. A 2- to 3-log10 reduction in kidney and brain CE was observed. In both models, reduction in tissue fungal burden was corroborated with histopathological data, with target organs showing reduced or no abscesses in fosmanogepix-treated mice. Survival and tissue clearance were comparable to a clinically relevant high dose of liposomal amphotericin B (10 to 15 mg/kg). Our data support the continued development of fosmanogepix as a first-in-class treatment for infections caused by these rare molds.