Itraconazole: an update on pharmacology and clinical use for treatment of invasive and allergic fungal infections

Thiophene-Linked 1,2,4-Triazoles: Synthesis, Structural Insights and Antimicrobial and Chemotherapeutic Profiles

The reaction of thiophene-2-carbohydrazide 1 or 5-bromothiophene-2-carbohydrazide 2 with various haloaryl isothiocyanates and subsequent cyclization by heating in aqueous sodium hydroxide yielded the corresponding 4-haloaryl-5-(thiophen-2-yl or 5-bromothiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 5a-e. The triazole derivatives 5a and 5b were reacted with different secondary amines and formaldehyde solution to yield the corresponding 2-aminomethyl-4-haloaryl-2,4-dihydro-3H-1,2,4-triazole-3-thiones 6a-e, 7a-e, 8, 9, 10a and 10b in good yields. The in vitro antimicrobial activity of compounds 5a-e, 6a-e, 7a-d, 8, 9, 10a and 10b was evaluated against a panel of standard pathogenic bacterial and fungal strains. Compounds 5a, 5b, 5e, 5f, 6a-e, 7a-d, 8, 9, 10a and 10b showed marked activity, particularly against the tested Gram-positive bacteria and the Gram-negative bacteria Escherichia coli, and all the tested compounds were almost inactive against all the tested fungal strains. In addition, compounds 5e, 6a-e, 7a-d and 10a exhibited potent anti-proliferative activity, particularly against HepG-2 and MCF-7 cancer cell lines (IC50 < 25 μM). A detailed structural insight study based on the single crystals of compounds 5a, 5b, 6a, 6d and 10a is also reported. Molecular docking studies of the highly active antibacterial compounds 5e, 6b, 6d, 7a and 7d showed a high affinity for DNA gyrase. Meanwhile, the potent anti-proliferative activity of compounds 6d, 6e and 7d may be attributed to their high affinity for cyclin-dependent kinase 2 (CDK2).

Formulation and evaluation of itraconazole-loaded nanoemulgel for efficient topical delivery to treat fungal infections

Aim: The clinical application of conventional oral dosage form of itraconazole is limited due to its poor bioavailability. The aim of the study was to develop nanoemulgel of Itraconazole for topical delivery. Method: Nanoemulsions were prepared, optimized and further incorporated into a gel and evaluated for homogeneity, pH, viscosity, spreadability, in vitro drug release and skin irritation studies. Results: Cumulative drug release from nanoemulsions was within the range of 37.24 to 47.63% at 10 h. Drug release % for all the nanoemulgel formulations at10 h was 32.39, 39.75 and 45.9% respectively. Nanoemulgel was non-irritant as demonstrated by skin irritation studies in animals. Conclusion: Itraconazole nanoemulgels were proved to be potential for effective topical delivery of drug with enhanced bioavailability.

Self-emulsifying micelles as a drug nanocarrier system for itraconazole oral bioavailability enhancement; in vitro and in vivo assessment

Itraconazole (ITZ) is a renowned antifungal medication, however its therapeutic efficacy is limited by low solubility and oral bioavailability. The current research work attempted to augment the oral bioavailability of ITZ by incorporating into self-emulsifying micelles (SEMCs). To fabricate the SEMCs, various preparation techniques including physical mixture, melt-emulsification, solvent evaporation and kneading, were opted by using different weight ratio of drug and solubilizers i.e. Gelucire-50/13 or Gelucire-44/14 and characterized both in vitro and in vivo. The prepared SEMCs were found to be in the size range from 63.4 ± 5.2 to 284.2 ± 19.5 nm with surface charges ranging from -16 ± 1.2 to -27 ± 2.0 mV. The drug solubility was improved to a reasonable extent with all investigated formulations, however, SEMCs in group 6 prepared by kneading method (KMG6) using Gelucire-44/14: drug (10:1 presented 87.6 folds' increase (964.93 ± 2 μg/mL) compared to solubility of crystalline ITZ (11 ± 2 μg/mL) through kneading method. In addition, KMG6 SEMCs shows the fast drug release compared to other SEMCs. Further, KMG6 SEMCs also exhibited 5.12-fold higher relative intestinal serosal fluid absorption compared to crystalline ITZ. The pharmacokinetic parameters such Cmax, AUC and Tmax of KMG6 SEMCs significantly improved compared to crystalline ITZ. In conclusion, the manipulation of ITZ solubility, dissolution rate and absorption using SEMCs is a promising strategy for bioavailability enhancement.

Genetic variations of CYP3A4 on the metabolism of itraconazole in vitro

Itraconazole is a triazole anti-infective drug that has been proven to prevent and treat a variety of fungal and viral infections and has been considered to be a potential therapeutic remedy for COVID-19 treatment. In this study, we aimed to completely evaluate the impacts of Cytochrome P450 3A4 (CYP3A4) variant proteins and drug interactions on the metabolism of itraconazole in recombinant insect microsomes, and to characterize the potential mechanism of substrate selectivity. Incubations with itraconazole (0.2-15 μM) in the presence/absence of lopinavir or darunavir were assessed by CYP3A4 variants, and the metabolite hydroxyitraconazole concentrations were measured by UPLC-MS/MS. Our data showed that when compared with CYP3A4.1, 4 variants (CYP3A4.9, .10, .28 and .34) displayed no significant differences, and 3 variants (CYP3A4.14, .15 and .19) exhibited increased intrinsic clearance (CLint), whereas the remaining 17 variant proteins showed decreased enzyme activities for the catalysis of itraconazole. Moreover, the inhibitory effects of lopinavir and darunavir on itraconazole metabolism varied in different degrees. Furthermore, different changed trend of the kinetic parameters in ten variants (CYP3A4.5, .9, .10, .16, .19, .24, .28, .29, .31, and .33) were observed, especially CYP3A4.5 and CYP3A4.16, and this may be related to the metabolic site-heme iron atom distance. In the present study, we functionally analyzed the effects of 25 CYP3A4 protein variants on itraconazole metabolism for the first time, and provided comprehensive data on itraconazole metabolism in vitro. This may help to better assess the metabolism and elimination of itraconazole in clinic to improve the safety and efficacy of its clinical treatment and also provide new possibilities for the treatment of COVID-19.

The OSR9 Regimen: A New Augmentation Strategy for Osteosarcoma Treatment Using Nine Older Drugs from General Medicine to Inhibit Growth Drive

As things stand in 2023, metastatic osteosarcoma commonly results in death. There has been little treatment progress in recent decades. To redress the poor prognosis of metastatic osteosarcoma, the present regimen, OSR9, uses nine already marketed drugs as adjuncts to current treatments. The nine drugs in OSR9 are: (1) the antinausea drug aprepitant, (2) the analgesic drug celecoxib, (3) the anti-malaria drug chloroquine, (4) the antibiotic dapsone, (5) the alcoholism treatment drug disulfiram, (6) the antifungal drug itraconazole, (7) the diabetes treatment drug linagliptin, (8) the hypertension drug propranolol, and (9) the psychiatric drug quetiapine. Although none are traditionally used to treat cancer, all nine have attributes that have been shown to inhibit growth-promoting physiological systems active in osteosarcoma. In their general medicinal uses, all nine drugs in OSR9 have low side-effect risks. The current paper reviews the collected data supporting the role of OSR9.

Prediction of gastric pH-mediated drug exposure using physiologically-based pharmacokinetic modeling: A case study of itraconazole

Abnormal gastric acidity, including achlorhydria, can act as a significant source of variability in orally administered drugs especially with pH-sensitive solubility profiles, such as weak bases, potentially resulting in an undesirable therapeutic response. This study aimed to evaluate the utility of physiologically-based pharmacokinetic (PBPK) modeling in the prediction of gastric pH-mediated drug exposure by using itraconazole, a weak base, as a case. An itraconazole PBPK model was developed on the mechanistic basis of its absorption kinetics in a middle-out manner from a stepwise in vitro-in vivo extrapolation to in vivo refinement. Afterward, an independent prospective clinical study evaluating gastric pH and itraconazole pharmacokinetics (PKs) under normal gastric acidity and esomeprazole-induced gastric hypoacidity was conducted for model validation. Validation was performed by comparing the predicted data with the clinical observations, and the valid model was subsequently applied to predict PK changes under achlorhydria. The developed itraconazole PBPK model showed reasonable reproducibility for gastric pH-mediated exposure observed in the clinical investigation. Based on the model-based simulations, itraconazole exposure was expected to be decreased up to 65% under achlorhydria, and furthermore, gastric pH-mediated exposure could be mechanistically interpreted according to sequential variation in total solubility, dissolution, and absorption. This study suggested the utility of PBPK modeling in the prediction of gastric pH-mediated exposure, especially for drugs whose absorption is susceptible to gastric pH. Our findings will serve as a leading model for further mechanistic assessment of exposure depending on gastric pH for various drugs, ultimately contributing to personalized pharmacotherapy.

High-throughput identification and determination of antifungal triazoles in human plasma using UPLC-QDa

Triazoles are common agents for invasive fungal infections, while therapeutic drug monitoring is needed to improve antifungal efficacy and reduce toxicity. This study aimed to exploit a simple and reliable liquid chromatography-mass spectrometry method for high-throughput monitoring of antifungal triazoles in human plasma using UPLC-QDa. Triazoles in plasma were separated by chromatography on a Waters BEH C18 column and detected using positive ions electrospray ionization fitted with single ion recording. M⁺ for fluconazole (m/z 307.11) and voriconazole (m/z 350.12), M²⁺ for posaconazole (m/z 351.17), itraconazole (m/z 353.13) and ketoconazole (m/z 266.08, IS) were selected as representative ions in single ion recording mode. The standard curves in plasma showed acceptable linearities over 1.25-40 μg/mL for fluconazole, 0.47-15 μg/mL for posaconazole and 0.39-12.5 μg/mL for voriconazole and itraconazole. The selectivity, specificity, accuracy, precision, recovery, matrix effect, and stability met acceptable practice standards under Food and Drug Administration method validation guidelines. This method was successfully applied to the therapeutic monitoring of triazoles in patients with invasive fungal infections, thereby guiding clinical medication.

Pharmacokinetics/Pharmacodynamics study of Fixtral SB as compared to supra bioavailable itraconazole and conventional itraconazole

BACKGROUND

Itraconazole is a broad-spectrum triazole antifungal inhibiting fungal growth by inhibiting ergosterol synthesis and exhibits a nonlinear pharmacokinetic profile. Erratic absorption pattern with wide fluctuations in blood levels causes inconsistent and unpredictable clinical behaviour of this drug despite its low minimum inhibitory concentration (MIC) as compared to other antifungal agents.

AIM

To compare the oral bioavailability and bioequivalence of Fixtral SB (supra bioavailable itraconazole) with reference product R2 (supra bioavailable 2 × 50 mg itraconazole).

METHODS

The study population consisted of 54 healthy volunteers, aged between 18-45 years and randomized to receive a single oral dose of either test [T; Fixtral SB (supra bioavailable itraconazole) 100 mg] or reference product (R1; Sporanox 100 mg × 2 capsules and R2; Lozanoc capsules 50 mg × 2 capsules). Blood samples were taken pre-dose and post-dose up to 96 h. The study evaluated bioequivalence by comparing the oral bioavailability of the test product with reference product R2. The pharmacodynamic characteristics of the drug were evaluated by comparing the test product with reference product R1. Pharmacokinetics (PK)-PD comparative analysis [area under the concentration-time curve (AUC)/ minimum inhibitory concentration (MIC) > 25] was performed for conventional itraconazole 100 mg and supra bioavailable itraconazole 50 mg. Adverse events (AEs) assessments were performed in each study period and post-study evaluation.

RESULTS

Statistical analysis of primary PK variables revealed bioequivalence, with confidence intervals being completely inside the acceptance criteria of 80%-125%. The peak concentration levels of itraconazole were achieved at 10 h (T) and 8.5 h (R2), respectively. Pharmacodynamic parameter assessment showed that AUC/MIC for R1 are comparable to Fixtral SB 100mg for MIC levels up to 16mcg/mL (P > 0.05 and observed P = 0.3196). Six AEs were observed that were mild to moderate in severity and resolved. No severe AE was reported.

CONCLUSION

Test product itraconazole Capsule 100 mg is bioequivalent with the reference product (R2) at 100 mg dose (2 capsules of Lozanoc^® 50 mg) under fed conditions. Pharmacodynamics activity in terms of AUC/MIC is comparable between the test product at 100 mg dose and marketed itraconazole 200 mg. Fixtral SB is expected to have therapeutically similar efficacy at half the equivalent dose. Tested formulations were found to be safe and well tolerated.

Virtual screening and molecular dynamics simulations provide insight into repurposing drugs against SARS-CoV-2 variants Spike protein/ACE2 interface

After over two years of living with Covid-19 and hundreds of million cases worldwide there is still an unmet need to find proper treatments for the novel coronavirus, due also to the rapid mutation of its genome. In this context, a drug repositioning study has been performed, using in silico tools targeting Delta Spike protein/ACE2 interface. To this aim, it has been virtually screened a library composed by 4388 approved drugs through a deep learning-based QSAR model to identify protein-protein interactions modulators for molecular docking against Spike receptor binding domain (RBD). Binding energies of predicted complexes were calculated by Molecular Mechanics/Generalized Born Surface Area from docking and molecular dynamics simulations. Four out of the top twenty ranking compounds showed stable binding modes on Delta Spike RBD and were evaluated also for their effectiveness against Omicron. Among them an antihistaminic drug, fexofenadine, revealed very low binding energy, stable complex, and interesting interactions with Delta Spike RBD. Several antihistaminic drugs were found to exhibit direct antiviral activity against SARS-CoV-2 in vitro, and their mechanisms of action is still debated. This study not only highlights the potential of our computational methodology for a rapid screening of variant-specific drugs, but also represents a further tool for investigating properties and mechanisms of selected drugs.

Pharmacokinetic and clinical comparison of super-bioavailable itraconazole and conventional itraconazole at different dosing in dermatophytosis

Background

Due to changing face of dermatophytosis in India, many dermatologists practice different dosing patterns of itraconazole (ITZ). Recently, a new form of ITZ, super-bioavailable ITZ (SBITZ), has been commercialized to overcome the pharmacokinetic challenges of conventional ITZ (CITZ). Serum and sebum concentration of ITZ plays an important role in the management of dermatophytosis. Hence, the current study compares the rate and extent of serum and sebum concentration of SBITZ and CITZ at different dosing to determine their efficacy and safety in patients with dermatophytosis.

Methods

This was an open-label, randomized, four-arm study including 40 adult patients diagnosed with glabrous tinea who were randomized equally into four groups to receive either CITZ-100-BD or CITZ-200-OD (2×100 mg capsules) or SBITZ-130-OD or SBITZ-100-OD (2×SBITZ-50 mg capsules) for 4 weeks. Serum and sebum samples were analysed at different time intervals along with clinical efficacy and safety.

Results

For serum concentration, on day 28, the arithmetic mean and standard deviation (SD) for CITZ-100-BD, CITZ-200-OD, SB-130-OD and SB100-OD were 1262±233.5 ng/mL, 1704±261.6 ng/mL, 1770±268.9 ng/mL and 1520±231.7 ng/mL, respectively, which was statistically significant for OD dosing of ITZ/SBITZ over CITZ-100-BD. Similarly, for sebum concentration, the arithmetic mean and SD for CITZ-100-BD, CITZ-200-OD, SB-130-OD and SB-100-OD were 1042±163.45 ng/mg, 1423±192.46 ng/mg, 1534±227.55 ng/mg and 1107±182.35 ng/mg, respectively, which was statistically significant for SB-130-OD and CITZ-200-OD over CITZ-100-BD and SBITZ-100-OD dosing. No significant difference was noted between SBITZ-130 and CITZ-200 (p=0.25). Only two patients achieved complete cure in the SBITZ-130 group, whereas no patients achieved the same in other groups (p=0.47). All the dosages were very well tolerated with only 12 adverse events reported by ten patients in all groups.

Conclusion

All formulations achieved desired serum and sebum concentrations required for efficacy in dermatophytosis, but SB 130 mg OD and CITZ 200 mg OD were statistically significant than other ITZ doses in achieving sebum concentration. Additionally, SBITZ 130 mg OD was bioequivalent to CITZ 200 mg OD and achieved similar results to those of CITZ 200 mg OD but at 35% lower drug concentrations.

Optimization of O/W Emulsion Solvent Evaporation Method for Itraconazole Sustained Release Microspheres

Itraconazole, a commonly used antifungal drug in the clinic approved by U.S. Food and Drug Administration (FDA), has been gradually found to have anti-tumor, angiogenesis inhibition and other pharmacological activities. However, its poor water solubility and potential toxicity limited its clinical application. In order to improve the water solubility and reduce the side effects caused by the high concentration of itraconazole, a novel preparation method of itraconazole sustained release microspheres was established in this study. Firstly, five kinds of polylactic acid-glycolic acid (PLGA) microspheres loaded with itraconazole were prepared by oil/water (O/W) emulsion solvent evaporation and then characterized by infrared spectroscopy. Then the particle size and morphology of the microspheres were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). After that, the particle size distribution, drug loading rate, entrapment efficiency, and drug release experiments were evaluated. Our results showed the microspheres prepared in this study had uniform particle size distribution and good integrity. Further study found that the average drug loading of the five kinds of microspheres prepared with PLGA 7505, PLGA 7510, PLGA 7520, PLGA 5020 and PLGA 0020 were 16.88, 17.72, 16.72, 16.57, and 16.64%, respectively, and the encapsulation rate all reached about 100%. More surprisingly, the release experimental results showed that the microspheres prepared with PLGA 7520 did not show sudden release, showing good sustained release performance and high drug release rate. To sum up, this study optimized the preparation method of sustained-release microspheres without sudden release, which provides a new solution for the delivery of itraconazole in the clinic.

Insight into the role of clathrin-mediated endocytosis inhibitors in SARS-CoV-2 infection

Emergence of SARS-CoV-2 variants warrants sustainable efforts to upgrade both the diagnostic and therapeutic protocols. Understanding the details of cellular and molecular basis of the virus-host cell interaction is essential for developing variant-independent therapeutic options. The internalization of SARS-CoV-2, into lung epithelial cells, is mediated by endocytosis, especially clathrin-mediated endocytosis (CME). Although vaccination is the gold standard strategy against viral infection, selective inhibition of endocytic proteins, complexes, and associated adaptor proteins may present a variant-independent therapeutic strategy. Although clathrin and/or dynamins are the most important proteins involved in CME, other endocytic mechanisms are clathrin and/or dynamin independent and rely on other proteins. Moreover, endocytosis implicates some subcellular structures, like plasma membrane, actin and lysosomes. Also, physiological conditions, such as pH and ion concentrations, represent an additional factor that mediates these events. Accordingly, endocytosis related proteins are potential targets for small molecules that inhibit endocytosis-mediated viral entry. This review summarizes the potential of using small molecules, targeting key proteins, participating in clathrin-dependent and -independent endocytosis, as variant-independent antiviral drugs against SARS-CoV-2 infection. The review takes two approaches. The first outlines the potential role of endocytic inhibitors in preventing endocytosis-mediated viral entry and its mechanism of action, whereas in the second computational analysis was implemented to investigate the selectivity of common inhibitors against endocytic proteins in SARS-CoV-2 endocytosis. The analysis revealed that remdesivir, methyl-β-cyclodextrin, rottlerin, and Bis-T can effectively inhibit clathrin, HMG-CoA reductase, actin, and dynamin I GTPase and are more potent in inhibiting SARS-CoV-2 than chloroquine. CME inhibitors for SARS-CoV-2 infection remain understudied.

Influence of Gender, Body Mass Index, and Age on the Pharmacokinetics of Itraconazole in Healthy Subjects: Non-Compartmental Versus Compartmental Analysis

Itraconazole is a triazole antifungal agent with highly variable pharmacokinetics, with not yet fully identified factors as the source of this variability. Our study aimed to examine the influence of body mass index, gender, and age on the first dose pharmacokinetics of itraconazole in healthy subjects, using pharmacokinetic modeling, non-compartmental versus compartmental ones. A total of 114 itraconazole and hydroxy-itraconazole sets of plasma concentrations of healthy subjects of both genders, determined using a validated liquid chromatographic method with mass spectrometric detection (LC-MS), were obtained for pharmacokinetic analyses performed by the computer program Kinetica 5®. Genetic polymorphism in CYP3A4, CYP3A5, CYP1A1, CYP2C9, and CYP2C19 was analyzed using PCR-based methods. Multiple linear regression analysis indicated that gender had a significant effect on AUC as the most important pharmacokinetics endpoint, whereas body mass index and age did not show such an influence. Therefore, further analysis considered gender and indicated that both geometric mean values of itraconazole and hydroxy-itraconazole plasma concentrations in men were prominently higher than those in women. A significant reduction of the geometric mean values of Cmax and AUC and increment of Vd in females compared with males were obtained. Analyzed genotypes and gender differences in drug pharmacokinetics could not be related. Non-compartmental and one-compartmental models complemented each other, whereas the application of the two-compartmental model showed a significant correlation with the analysis of one compartment. They indicated a significant influence of gender on itraconazole pharmacokinetics after administration of the single oral dose of the drug, given under fed conditions. Women were less exposed to itraconazole and hydroxy-itraconazole than men due to poorer absorption of itraconazole, its more intense pre-systemic metabolism, and higher distribution of both drug and its metabolite.

Apical-out airway organoids as a platform for studying viral infections and screening for antiviral drugs

Airway organoids are polarized 3D epithelial structures that recapitulate the organization and many of the key functions of the in vivo tissue. They present an attractive model that can overcome some of the limitations of traditional 2D and Air–Liquid Interface (ALI) models, yet the limited accessibility of the organoids’ apical side has hindered their applications in studies focusing on host–pathogen interactions. Here, we describe a scalable, fast and efficient way to generate airway organoids with the apical side externally exposed. These apical-out airway organoids are generated in an Extracellular Matrix (ECM)-free environment from 2D-expanded bronchial epithelial cells and differentiated in suspension to develop uniformly-sized organoid cultures with robust ciliogenesis. Differentiated apical-out airway organoids are susceptible to infection with common respiratory viruses and show varying responses upon treatment with antivirals. In addition to the ease of apical accessibility, these apical-out airway organoids offer an alternative in vitro model to study host–pathogen interactions in higher throughput than the traditional air–liquid interface model.

Repurposing Antifungals for Host-Directed Antiviral Therapy?

Because of their epidemic and pandemic potential, emerging viruses are a major threat to global healthcare systems. While vaccination is in general a straightforward approach to prevent viral infections, immunization can also cause escape mutants that hide from immune cell and antibody detection. Thus, other approaches than immunization are critical for the management and control of viral infections. Viruses are prone to mutations leading to the rapid emergence of resistant strains upon treatment with direct antivirals. In contrast to the direct interference with pathogen components, host-directed therapies aim to target host factors that are essential for the pathogenic replication cycle or to improve the host defense mechanisms, thus circumventing resistance. These relatively new approaches are often based on the repurposing of drugs which are already licensed for the treatment of other unrelated diseases. Here, we summarize what is known about the mechanisms and modes of action for a potential use of antifungals as repurposed host-directed anti-infectives for the therapeutic intervention to control viral infections.

Use of Modeling and Simulation to Predict the Influence of Triazole Antifungal Agents on the Pharmacokinetics of Crizotinib

Crizotinib is used for the treatment of c-ros oncogene 1-positive advanced non-small-cell lung cancer. Triazole antifungal agents are widely used for invasive fungal infections in clinical practice. To predict the potential influence of different triazoles (voriconazole, fluconazole, and itraconazole) on the pharmacokinetics of crizotinib by modeling and simulation the physiologically based pharmacokinetic models were established and validated in virtual cancer subjects through Simcyp software based on the essential physicochemical properties and pharmacokinetic data collected. The validated physiologically based pharmacokinetic models were applied to predict the drug-drug interactions between crizotinib and different triazoles (voriconazole, fluconazole, or itraconazole) in patients with cancer. Crizotinib and triazole antifungal agents were administered orally. The predicted plasma concentration vs time profiles of crizotinib, voriconazole, fluconazole, and itraconazole showed good agreement with observed, respectively. The geometric mean area under the plasma concentration-time curve (AUC) of crizotinib was increased by 84%, 58%, and 79% when coadministered with voriconazole, fluconazole, or itraconazole at multiple doses, respectively. The drug-drug interaction results showed increased pharmacokinetic exposure (maximum plasma concentration and area under the plasma concentration-time curve) of crizotinib when coadministrated with different triazoles (voriconazole > itraconazole > fluconazole). Among the 3 triazoles, voriconazole exhibited the most significant influence on the pharmacokinetic exposure of crizotinib. In clinic, adverse drug reactions and toxicity related to crizotinib should be carefully monitored, and therapeutic drug monitoring for crizotinib is recommended to guide dosing and optimize treatment when coadministered with voriconazole, fluconazole, or itraconazole.

Pharmacologically induced endolysosomal cholesterol imbalance through clinically licensed drugs itraconazole and fluoxetine impairs Ebola virus infection in vitro

Ebola virus disease (EVD) is a severe and frequently lethal disease caused by Ebola virus (EBOV). The latest occasional EVD outbreak (2013–2016) in Western African, which was accompanied by a high fatality rate, showed the great potential of epidemic and pandemic spread. Antiviral therapies against EBOV are very limited, strain-dependent (only antibody therapies are available) and mostly restricted to symptomatic treatment, illustrating the urgent need for novel antiviral strategies. Thus, we evaluated the effect of the clinically widely used antifungal itraconazole and the antidepressant fluoxetine for a repurposing against EBOV infection. While itraconazole, similar to U18666A, directly binds to and inhibits the endosomal membrane protein Niemann-Pick C1 (NPC1), fluoxetine, which belongs to the structurally unrelated group of weakly basic, amphiphile so-called “functional inhibitors of acid sphingomyelinase” (FIASMA) indirectly acts on the lysosome-residing acid sphingomyelinase via enzyme detachment leading to subsequent lysosomal degradation. Both, the drug-induced endolysosomal cholesterol accumulation and the altered endolysosomal pH, might interfere with the fusion of viral and endolysosomal membrane, preventing infection with EBOV. We further provide evidence that cholesterol imbalance is a conserved cross-species mechanism to hamper EBOV infection. Thus, exploring the endolysosomal host–pathogen interface as a suitable antiviral treatment may offer a general strategy to combat EBOV infection.

Recent Perspectives in the Management of Fungal Keratitis

Mycotic keratitis is common in warm, humid regions with a varying profile of pathogenic fungi according to geographical origin, socioeconomic status, and climatic condition. Clinical diagnosis can be challenging in difficult cases and those refractory to treatment. Fungal hyphae on microscopic examination and culture isolation have been the gold standard in the laboratory diagnosis of fungal keratitis. A culture isolate of the aetiological fungus is essential to perform antifungal susceptibility testing. As the culture isolation of fungi is time-consuming, causing delays in the initiation of treatment, newer investigative modalities such as in vivo confocal microscopy and molecular diagnostic methods have recently gained popularity. Molecular diagnostic techniques now help to obtain a rapid diagnosis of fungal keratitis. Genomic approaches are based on detecting amplicons of ribosomal RNA genes, with internal transcribed spacers being increasingly adopted. Metagenomic deep sequencing allows for rapid and accurate diagnosis without the need to wait for the fungus to grow. This is also helpful in identifying new emerging strains of fungi causing mycotic keratitis. A custom-tear proteomic approach will probably play an important diagnostic role in future in the management of mycotic keratitis. Positive repeat cultures are being suggested as an important gauge indicative of a poor prognosis. Positive repeat fungal cultures help to modify a treatment regimen by increasing its frequency, providing the addition of another topical and oral antifungal agent along with close follow-up for perforation and identifying need for early therapeutic keratoplasty. The role of collagen crosslinking in the treatment of fungal keratitis is not convincingly established. Rapid detection by multiplex PCR and antifungal susceptibility testing of the pathogenic fungi, adopted into a routine management protocol of fungal keratitis, will help to improve treatment outcome. Early therapy is essential in minimizing damage to the corneal tissue, thereby providing a better outcome. The role of conventional therapy with polyenes, systemic and targeted therapy of antifungal agents, newer azoles and echinocandins in fungal keratitis has been widely studied in recent times. Combination therapy can be more efficacious in comparison to monotherapy. Given the diversity of fungal aetiology, the emergence of new corneal pathogenic fungi with varying drug susceptibilities, increasing the drug resistance to antifungal agents in some genera and species, it is perhaps time to adopt recent molecular methods for precise identification and incorporate antifungal susceptibility testing as a routine.

Population Pharmacokinetics and Pharmacodynamics of Itraconazole for Disseminated Infection Caused by Talaromyces marneffei

First-line treatment of talaromycosis with amphotericin B deoxycholate (DAmB) is labor-intensive and toxic. Itraconazole is an appealing alternative antifungal agent. Pharmacokinetic data were obtained from 76 patients who were randomized to itraconazole in the Itraconazole versus Amphotericin B for Talaromycosis (IVAP) trial. Plasma levels of itraconazole and its active metabolite, hydroxyitraconazole, were analyzed alongside longitudinal fungal CFU counts in a population model. Itraconazole and hydroxyitraconazole pharmacokinetic variability was considerable, with areas under the concentration-time curve over 24 h (AUC24) of 3.34 ± 4.31 mg·h/liter and 3.57 ± 4.46 mg·h/liter (mean ± standard deviation), respectively. Levels of both analytes were low; itraconazole minimum concentration (Cmin) was 0.11 ± 0.16 mg/liter, and hydroxyitraconazole Cmin was 0.13 ± 0.17 mg/liter. The mean maximal rates of drug-induced killing were 0.206 and 0.208 log10 CFU/ml/h, respectively. There were no associations between itraconazole Cmin/MIC and time to sterilization of the bloodstream (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.99 to 1.03; P = 0.43), time to death (HR, 0.99; 95% CI, 0.96 to 1.02; P = 0.77), or early fungicidal activity (EFA) (coefficient, -0.004; 95% CI, -0.010 to 0.002; P = 0.18). Similarly, there was no relationship between AUC/MIC and time to sterilization of the bloodstream (HR, 1.00; 95% CI, 0.99 to 1.00; P = 0.50), time to death (HR, 1.00; 95% CI, 0.99 to 1.00; P = 0.91), or EFA (coefficient, -0.0001; 95% CI, -0.0003 to 0.0001; P = 0.19). This study raises the possibility that the failure of itraconazole to satisfy noninferiority criteria against DAmB for talaromycosis in the IVAP trial was a pharmacokinetic and pharmacodynamic failure.

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.

Potent antifungal agents and use of nanocarriers to improve delivery to the infected site: A systematic review

There are four major classes of antifungals with the predominant mechanism of action being targeting of cell wall or cell membrane. As in other drugs, low solubility of these compounds has led to low bioavailability in target tissues. Enhanced drug dosages have effects such as toxicity, drug-drug interactions, and increased drug resistance by fungi. This article reviews the current state-of-the-art of antifungals, structure, mechanism of action, other usages, and toxic side effects. The emergence of nanoformulations to transport and uniformly release cargo at the target site is a boon in antifungal treatment. The article details research that lead to the development of nanoformulations of antifungals and potential advantages and avoidance of the lacunae characterizing conventional drugs. A range of nanoformulations based on liposomes, polymers are in various stages of research and their potential advantages have been brought out. It could be observed that under similar dosages, test models, and duration, nanoformulations provided enhanced activity, reduced toxicity, higher uptake and higher immunostimulatory effects. In most instances, the mechanism of antifungal activity of nanoformulations was similar to that of regular antifungal. There are possibilities of coupling multiple antifungals on the same nano-platform. Increased activity coupled with multiple mechanisms of action presents for nanoformulations a tremendous opportunity to overcome antifungal resistance. In the years to come, robust methods for the preparation of nanoformulations taking into account the repeatability and reproducibility in action, furthering the studies on nanoformulation toxicity and studies of human models are required before extensive use of nanoformulations as a prescribed drug.

Bioavailability of Single-Dose SUBA-Itraconazole Compared to Conventional Itraconazole under Fasted and Fed Conditions

Conventional itraconazole (C-ITZ) suffers from absorption variability. SUBA-itraconazole (S-ITZ) is more bioavailable than C-ITZ at steady state in a fed condition, but there are no data comparing the two under a fasted state. An open-label, single-dose, randomized, bioequivalence study was performed comparing S-ITZ to C-ITZ capsules under fasted and fed conditions in healthy adults measuring itraconazole and hydroxyitraconazole plasma levels. This study demonstrated less variability of S-ITZ compared to C-ITZ capsules under fasted conditions.

Drug-drug interaction between itraconazole capsule and efavirenz in adults with HIV for talaromycosis treatment

OBJECTIVES

To assess the pharmacokinetic of itraconazole capsule formulation and its active metabolite, hydroxyitraconazole, in adults with HIV diagnosed with talaromycosis in an endemic area, and to evaluate the drug-drug interaction between itraconazole/hydroxyitraconazole (ITC/OH-ITC) and efavirenz.

METHODS

Open-label, single arm, sequential pharmacokinetic study. Eligible subjects were adults with HIV, ≥18 years old, with confirmed talaromycosis, initiating itraconazole capsule as part of standard talaromycosis treatment, in whom efavirenz-based ART was anticipated. Steady-state pharmacokinetic assessments (pre-dose and at 1, 3, 4, 5, 6, 8 and 12 h post dose) were performed for itraconazole/hydroxyitraconazole without and with efavirenz use. Mid-dose efavirenz concentrations were also assessed. Pharmacokinetics parameters were calculated using non-compartmental analysis.

RESULTS

Ten subjects (70% male) were enrolled. At entry, median (range) age was 29.5 years (22-64), and CD4 cell count was 18.0 (1-39) cells/mm3. Geometric mean (95% CI) of itraconazole and hydroxyitraconazole AUC0-12 without efavirenz were 9097 (6761-12 239) and 11 705 (8586-15 959) ng·h/mL, respectively, with a median metabolic ratio of OH-ITC : ITC of 1.3 (95% CI 0.9-1.9). Intra-subject comparison revealed that both itraconazole and hydroxyitraconazole exposures were significantly reduced with concomitant efavirenz use, with the mean AUC0-12 of itraconazole and hydroxyitraconazole being 86% (71%-94%) and 84% (64%-97%) lower, respectively. With efavirenz, itraconazole trough concentrations were also below the recommended therapeutic level (0.5 μg/mL). All subjects had mid-dose efavirenz concentrations >1000 ng/mL.

CONCLUSIONS

Concomitant administration of itraconazole capsule with efavirenz significantly reduced itraconazole and hydroxyitraconazole exposures. The clinical impact of this drug-drug interaction on talaromycosis treatment or prophylaxis in the era of potent ART needs further evaluation.

Inhaled Antifungal Agents for the Treatment and Prophylaxis of Pulmonary Mycoses

Pulmonary mycoses are associated with high morbidity and mortality. The current standard treatment by systemic administration is limited by inadequate local bioavailability and systemic toxic effects. Aerosolisation of antifungals is an attractive approach to overcome these problems, but no inhaled antifungal formulation is currently available for the treatment of pulmonary mycoses. Hence, the development of respirable antifungals formulations is of interest and in high demand. In this review, the recent advances in the development of antifungal formulations for pulmonary delivery are discussed, including both nebulised and dry powder formulations. Although the clinical practices of nebulised parenteral amphotericin B and voriconazole formulations (off-label use) are reported to show promising therapeutic effects with few adverse effects, there is no consensus about the dosage regimen (e.g. the dose, frequency, and whether they are used as single or combination therapy). To maximise the benefits of nebulised antifungal therapy, it is important to establish standardised protocol that clearly defines the dose and specifies the device and the administration conditions. Dry powder formulations of antifungal agents such as itraconazole and voriconazole with favourable physicochemical and aerosol properties are developed using various powder engineering technologies, but it is important to consider their suitability for use in patients with compromised lung functions. In addition, more biological studies on the therapeutic efficacy and pharmacokinetic profile are needed to demonstrate their clinical potential.

Antifungals in Clinical Use and the Pipeline

Over the past 15 years, there has been an increase in the development and utilization of newer antifungal agents. The ideal antifungal, however, in regard to spectrum of activity, pharmacokinetic/pharmacodynamic properties, development of resistance, safety, and drug interaction profile remains elusive. This article reviews pharmacologic aspects of Food and Drug Administration-approved polyenes, flucytosine, azoles, and echinocandins as well as promising pipeline antifungal agents. Unique properties of these newer agents are highlighted. The clinical role of established and investigational antifungal agents as treatment and/or prevention of invasive fungal infections is discussed.

Oral itraconazole for epistaxis in hereditary hemorrhagic telangiectasia: a proof of concept study

The inhibiting effects of itraconazole, an antifungal drug on vascular endothelial growth factor (VEGF) have recently been discovered. By inhibiting VEGF, itraconazole has shown potential in clinical trials as anti-cancer treatment. In hereditary hemorrhagic telangiectasia (HHT) patients, VEGF levels are elevated and inhibition of VEGF can decrease bleeding. Itraconazole could potentially serve as anti-angiogenic therapy for HHT-related bleeding. We report a proof of concept study with HHT patients and severe epistaxis. Patients were treated with daily 200 mg orally administered itraconazole for sixteen weeks. Twenty-one HHT patients, 8 females (38%), 13 males (62%), median age of 59 years (interquartile range (IQR) 55-69) were enrolled. Of these patients, 13 (62%) were diagnosed with HHT type 1, seven (33%) with HHT type 2 and in one patient (5%), no pathognomonic HHT mutation was found. Four patients (19%) prematurely terminated the study (3 due to mild or moderate side-effects) resulting in 17 patients included in the analyses. The median epistaxis severity score significantly decreased during treatment from 6.0 (IQR 5.1-7.2) to 3.8 (IQR 3.1-5.2) (p = 0.006). The monthly epistaxis frequency decreased from 56 to 38 epistaxis episodes (p = 0.004) and the monthly duration from 407 to 278 minutes (p = 0.005). Hemoglobin levels did not significantly change. The quality of life showed a small but significant improvement. In conclusion, oral itraconazole significantly improved epistaxis in HHT patients. The potential benefit of itraconazole in HHT should be further investigated.

Emergomycosis, an Emerging Systemic Mycosis in Immunocompromised Patients: Current Trends and Future Prospects

Recently, the global emergence of emergomycosis, a systemic fungal infection caused by a novel dimorphic fungus Emergomyces species has been observed among immunocompromised individuals. Though initially classified under the genus Emmonsia, a taxonomic revision in 2017 based on DNA sequence analyses placed five Emmonsia-like fungi under a separate genus Emergomyces. These include Emergomyces pasteurianus, Emergomyces africanus, Emergomyces canadensis, Emergomyces orientalis, and Emergomyces europaeus. Emmonsia parva was renamed as Blastomyces parvus, while Emmonsia crescens and Emmonsia sola remained within the genus Emmonsia until a taxonomic revision in 2020 placed both the species under the genus Emergomyces. However, unlike other members of the genus, Emergomyces crescens and Emergomyces sola do not cause disseminated disease. The former causes adiaspiromycosis, a granulomatous pulmonary disease, while the latter has not been associated with human disease. So far, emergomycosis has been mapped across four continents: Asia, Europe, Africa and North America. However, considering the increasing prevalence of HIV/AIDS, it is presumed that the disease must have a worldwide distribution with many cases going undetected. Diagnosis of emergomycosis remains challenging. It should be considered in the differential diagnosis of histoplasmosis as there is considerable clinical and histopathological overlap between the two entities. Sequencing the internal transcribed spacer region of ribosomal DNA is considered as the gold standard for identification, but its application is compromised in resource limited settings. Serological tests are non-specific and demonstrate cross-reactivity with Histoplasma galactomannan antigen. Therefore, an affordable, accessible, and reliable diagnostic test is the need of the hour to enable its diagnosis in endemic regions and also for epidemiological surveillance. Currently, there are no consensus guidelines for the treatment of emergomycosis. The recommended regimen consists of amphotericin B (deoxycholate or liposomal formulation) for 1–2 weeks, followed by oral itraconazole for at least 12 months. This review elaborates the taxonomic, clinical, diagnostic, and therapeutic aspects of emergomycosis. It also enumerates several novel antifungal drugs which might hold promise in the treatment of this condition and therefore, can be potential areas of future studies.

Thermosensitive and mucoadhesive in situ ocular gel for effective local delivery and antifungal activity of itraconazole nanocrystal in the treatment of fungal keratitis

Itraconazole is a lipophilic drug, which limits its absorption for ocular administration. This study focused on the incorporation of itraconazole into nanocrystalline carrier system with stabilizer Pluronic® F127 and was further formulated into thermosensitive in situ ocular gel. Itraconazole nanocrystals (ITZ-NCs) were fabricated using media milling method with ultra-small-scale device. The obtained nanocrystals were observed to have a better in vitro activity against C. albicans (CA) compared to free itraconazole suspension in water. Furthermore, the optimization of the thermosensitive ocular gel formula was carried out with a central composite design, using three types of polymers, namely Pluronic® F127, Pluronic® F68, and hydroxypropyl methylcellulose (HPMC). After being dispersed into the optimized thermosensitive gel base, ITZ-NCs did not alter in terms of physical characteristics. Ex vivo ocularkinetic studies on infected porcine eye models showed a better profile of the optimized formula of thermosensitive in situ ocular gel when compared to standard gel base. Importantly, the ex vivo antifungal activity of these preparations was also increased, with a 93% decrease in the CA population observed after 48 h in infected porcine eye model. Altogether, this work has provided evidence of a novel approach in developing more advanced treatments for fungal keratitis.

Drug synergy of combinatory treatment with remdesivir and the repurposed drugs fluoxetine and itraconazole effectively impairs SARS-CoV-2 infection in vitro

Background and Purpose

The SARS‐COV‐2 pandemic and the global spread of coronavirus disease 2019 (COVID‐19) urgently call for efficient and safe antiviral treatment strategies. A straightforward approach to speed up drug development at lower costs is drug repurposing. Here, we investigated the therapeutic potential of targeting the interface of SARS CoV‐2 with the host via repurposing of clinically licensed drugs and evaluated their use in combinatory treatments with virus‐ and host‐directed drugs in vitro.

Experimental Approach

We tested the antiviral potential of the antifungal itraconazole and the antidepressant fluoxetine on the production of infectious SARS‐CoV‐2 particles in the polarized Calu‐3 cell culture model and evaluated the added benefit of a combinatory use of these host‐directed drugs with the direct acting antiviral remdesivir, an inhibitor of viral RNA polymerase.

Key Results

Drug treatments were well‐tolerated and potently impaired viral replication. Importantly, both itraconazole–remdesivir and fluoxetine–remdesivir combinations inhibited the production of infectious SARS‐CoV‐2 particles > 90% and displayed synergistic effects, as determined in commonly used reference models for drug interaction.

Conclusion and Implications

Itraconazole–remdesivir and fluoxetine–remdesivir combinations are promising starting points for therapeutic options to control SARS‐CoV‐2 infection and severe progression of COVID‐19.

Significant elevation of free itraconazole concentration at onset of adverse effects: A case report

Free itraconazole and hydroxyitraconazole concentrations were markedly elevated despite almost no changes in total concentrations when itraconazole was discontinued due to adverse effects. Elevated free itraconazole concentration may have a causal relationship with the development of adverse effects.

Preparation and validation of cyclodextrin-based excipients for radioiodinated hypericin applied in a targeted cancer radiotherapy

BACKGROUND

Iodine-131 labeled hypericin (¹³¹I-Hyp) has been utilized as a necrosis-avid theragnostic tracer in a dual targeting pan-anticancer strategy called OncoCiDia. Widespread use of previously-tested solvent dimethyl sulfoxide (DMSO) is limited by safety concerns. To tackle this, the present study was designed to explore a clinically feasible excipient for the formulation of the hydrophobic ¹³¹I-Hyp for intravenous administration.

METHOD

Solubility of Hyp in serial solutions of already-approved hydroxypropyl-β-cyclodextrin (HP-β-CD) was evaluated by UVspectrophotometry and 50% HP-β-CD was chosen for further experiments. Two novel HP-β-CD-based formulations of ¹³¹I-Hyp were compared with previous DMSO-based formulation, with regards to necrosis-targetability and biodistribution, by magnetic resonance imaging, single-photon emission computed tomography (SPECT), gamma counting, autoradiography, fluorescence microscopy and histopathology.

RESULTS

Hyp solubility was enhanced with increasing HP-β-CD concentrations. The radiochemical purity of ¹³¹I-Hyp was higher than 90% in all formulations. The necrosis-targetability of ¹³¹I-Hyp in the novel formulations was confirmed in vivo by SPECT and in vitro by autoradiography, fluorescence microscopy and histopathology. The plasma clearance of radioactivity was faster in the novel formulations.

CONCLUSION

The novel ¹³¹I-Hyp formulations with HP-β-CD could be a suitable pharmaceutical excipient for ¹³¹I-Hyp for intravenous administration.

pH-Responsive copolymer micelles to enhance itraconazole efficacy against Candida albicans biofilms

Candida albicans (C. albicans) is a common fungal pathogen causing both localised and systemic infections. The majority of these infections are promoted by biofilm formation, providing a protective matrix for the embedded fungi thereby evading the host immune defence and promoting resistance against anti-mycotic agents. In this study, pH-responsive micellar systems based on poly-(ethylene glycol) ethyl ether methacrylate (PEGMA) and poly 2-(diethylamino) ethyl methacrylate (DEAEMA) block-copolymers of P(PEGMA-b-DEAEMA) were specifically developed and loaded with the antifungal itraconazole (ICZ) to defeat C. albicans biofilms. The P(PEGMA-b-DEAEMA) di-block polymer micelles demonstrated a particle size of 55 ± 6 nm and high ICZ loads (12.0 ± 0.5% w/w). Within the biofilm's acidic microenvironment, tertiary amines of the pH-sensitive DEAEMA block are protonated, altering their conformation and enhancing the release of the micellar contents. Encapsulation of ICZ within micelles significantly enhanced the activity against C. albicans biofilms, with a significant reduction in the biofilm biomass (>50%) and in the number of viable cells (2.4 Log reduction) achieved, compared with the non-encapsulated ICZ. Confocal microscopy revealed a high affinity and accumulation of the micelles in C. albicans biofilms as a result of their size and specific electrostatic interaction, hence their improved activity. P(PEGMA-b-DEAEMA) based pH-responsive micelles offer significant potential as antifungal carriers for controlling Candida infections.

Experimental measurement - correlation of solubility and dissolution thermodynamics study of itraconazole in pure monosolvents at various temperatures

The information about the solubility and thermodynamic properties of solution is important for pharmaceutically important processes, formulation development, and further theoretical studies. In the present study, the solid-liquid equilibrium (solubility) for itraconazole (ITC) was determined experimentally in 14 monosolvents at temperatures between 293.15 K and 318.15 K under pressure of 0.1 MPa. The mole fraction solubilities were found to increase with increasing temperatures and followed inverse trend with the polarity of selected solvents. Besides, KAT-LSER analysis was performed to study the effect of solvent. The results revealed that the solute-solvent interaction (43.94%) was much higher than that of solvent-solvent interaction (16.59%). Thermodynamic based models like van't Hoff equation, modified Apelblat equation, Buchowski-Ksiazaczak equation, and polynomial empirical equation were applied to fit and correlate the experimental solubilities. Overall relative average deviation (RAD) and overall root-mean square deviation (104×RMSD) were observed to be minimum with the empirical polynomial equation and attained the values of 0.0033 and 0.0047, respectively. Furthermore, theoretical ideal solubilities, activity coefficients, and thermodynamic properties of dissolution including molar enthalpy, molar entropy, molar Gibbs free energy, and excess enthalpy were estimated. Ideal solubilities were projected considerably higher than experimental solubilities at each studied temperature. Thermodynamic properties of dissolution indicated that the dissolution was not a spontaneous process; observed to be endothermic (ΔH0soln>0) and enthalpy driven (ΔS0soln>0). Such solid-liquid equilibrium data of ITC will be of immense help in process and formulation development in pharmaceutical sciences.

Rapid and Simple Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) Method for Simultaneous Quantifications of Triazole Antifungals in Human Serum

PURPOSE

To develop and validate a one-step, rapid and simple reversed-phase high-performance liquid chromatography (HPLC)-based protocol for the simultaneous measurement of voriconazole (VCZ), posaconazole (POSA), itraconazole (ITC) in serum/plasma.

METHODS

Calibration standards (CS) and quality control samples were prepared in drug-free serum by spiking with the triazoles at different concentrations. HPLC was performed with C₁₈ column, isocratic mobile phase after extraction with cold acetonitrile. The standardized method was tested in 2693 patients' serum/plasma samples.

RESULTS

Linearity of CS for ITC, VCZ and POSA was proportional to the nominal concentration (correlation coefficient > 0.999). Limit of detection (mg/L) for ITC, VCZ and POSA was 0.25, 0.25 and 0.125, respectively. The lower limit of quantification (mg/L) for ITC, VCZ and POSA was 0.5, 0.5 and 0.25, respectively. Precision and accuracy were in acceptable range with 100% average percentage recovery. No interferences from endogenous substances and other antimicrobial compounds were noted. In clinical samples, the therapeutic range achieved for VCZ was 39.9%. Whereas, 61.1% and 44% of samples with ITC and POSA, respectively, were in the sub-therapeutic range.

CONCLUSION

We developed a rapid and simple HPLC method to quantify common triazoles in a single chromatographic run allowing simultaneous measurement of different antifungals in a small volume of serum/plasma. Thus, therapeutic drug monitoring requests can be processed in one run without changing the protocol parameters, column or column conditioning thereby improving turnaround time.

Recycling the Purpose of Old Drugs to Treat Ovarian Cancer

The main challenge in ovarian cancer treatment is the management of recurrences. Facing this scenario, therapy selection is based on multiple factors to define the best treatment sequence. Target therapies, such as bevacizumab and polymerase (PARP) inhibitors, improved patient survival. However, despite their achievements, ovarian cancer survival remains poor; these therapeutic options are highly costly and can be associated with potential side effects. Recently, it has been shown that the combination of repurposed, conventional, chemotherapeutic drugs could be an alternative, presenting good patient outcomes with few side effects and low costs for healthcare institutions. The main aim of this review is to strengthen the importance of repurposed drugs as therapeutic alternatives, and to propose an in vitro model to assess the therapeutic value. Herein, we compiled the current knowledge on the most promising non-oncological drugs for ovarian cancer treatment, focusing on statins, metformin, bisphosphonates, ivermectin, itraconazole, and ritonavir. We discuss the primary drug use, anticancer mechanisms, and applicability in ovarian cancer. Finally, we propose the use of these therapies to perform drug efficacy tests in ovarian cancer ex vivo cultures. This personalized testing approach could be crucial to validate the existing evidences supporting the use of repurposed drugs for ovarian cancer treatment.

Cooperative Effects of an Antifungal Moiety and DMSO on Pore Formation over Lipid Membranes Revealed by Free Energy Calculations

Itraconazole is a triazole drug widely used in the treatment of fungal infections, and it is in clinical trials for treatment of several cancers. However, the drug suffers from poor solubility, while experiments have shown that itraconazole delivery in liposome nanocarriers improves both circulation half-life and tissue distribution. The drug release mechanism from the nanocarrier is still unknown, and it depends on several factors including membrane stability against defect formation. In this work, we used molecular dynamics simulations and potential of mean force (PMF) calculations to quantify the influence of itraconazole on pore formation over lipid membranes, and we compared the effect by itraconazole with a pore-stabilizing effect by the organic solvent dimethyl sulfoxide (DMSO). According to the PMFs, both itraconazole and DMSO greatly reduce the free energy of pore formation, by up to ∼20 kJ mol^-1. However, whereas large concentrations of itraconazole of 8 mol % (relative to lipid) were required, only small concentrations of a few mole % DMSO (relative to water) were sufficient to stabilize pores. In addition, itraconazole and DMSO facilitate pore formation by different mechanisms. Whereas itraconazole predominantly aids the formation of a partial defect with a locally thinned membrane, DMSO mainly stabilizes a transmembrane water needle by shielding it from the hydrophobic core. Notably, the two distinct mechanisms act cooperatively upon adding both itraconazole and DMSO to the membrane, as revealed by an additional reduction of the pore free energy. Overall, our simulations reveal molecular mechanisms and free energies of membrane pore formation by small molecules. We suggest that the stabilization of a locally thinned membrane as well as the shielding of a transmembrane water needle from the hydrophobic membrane core may be a general mechanism by which amphiphilic molecules facilitate pore formation over lipid membranes at sufficient concentrations.

Open-Label Crossover Oral Bioequivalence Pharmacokinetics Comparison for a 3-Day Loading Dose Regimen and 15-Day Steady-State Administration of SUBA-Itraconazole and Conventional Itraconazole Capsules in Healthy Adults

Super bioavailability (SUBA) itraconazole (S-ITZ), which releases drug in the duodenum, and conventional itraconazole (C-ITZ), which releases drug in the stomach, were compared in two pharmacokinetic (PK) studies: a 3-day loading dose study and a 15-day steady-state administration study. These were crossover oral bioequivalence studies performed under fed conditions in healthy adult volunteers. In the loading dose study, C-ITZ (two doses of 100 mg each) and S-ITZ (two doses of 65 mg each) were administered three times daily for 3 days and once on day 4 (n = 15). For the steady-state administration study, C-ITZ (two doses of 100 mg each) and S-ITZ (two doses of 65 mg each) were administered twice daily for 14 days and a last dose was administered 30 min after a meal on day 15 (n = 16). Blood samples collected throughout both studies were analyzed for ITZ and hydroxy-ITZ (OH-ITZ) levels. Least-squares geometric means were used to compare the maximum peak concentration of drug after administration at steady state prior to administration of the subsequent dose (C _{max_ss}), the minimum drug level after administration prior to the subsequent dose (C _trough), and the area under the curve over the dosing interval (AUC_tau) of each formulation. The ratios of itraconazole (ITZ) and OH-ITZ for S-ITZ to C-ITZ were between 107% and 118% in both studies for C _{max_ss}, C _trough, and AUC_tau, which were within the U.S. FDA-required bioequivalence range of 80% to 125%. At the end of the steady-state administration study, 13 of 16 volunteers obtained higher mean ITZ blood C _trough levels of >1,000 ng/ml when they were administered S-ITZ (81%) than when they were administered C-ITZ (44%). The study drugs were well tolerated in both studies, with similar adverse events (AEs). All treatment-emergent AEs resolved after study completion. One volunteer receiving C-ITZ discontinued due to a treatment-unrelated AE in the steady-state administration study. No serious AEs were reported. Total, trough, and peak ITZ and OH-ITZ exposures were similar between the two formulations. Therefore, SUBA-ITZ, which has 35% less drug than C-ITZ, was bioequivalent to C-ITZ in healthy adult volunteers and exhibited a safety profile similar to that of C-ITZ.

Combinatory Treatment with Oseltamivir and Itraconazole Targeting Both Virus and Host Factors in Influenza A Virus Infection

Influenza virus infections and their associated morbidity and mortality are a major threat to global health. Vaccination is an effective influenza prevention measure; however, the effectiveness is challenged by the rapid changes in the influenza virus genome leading to viral adaptation. Emerging viral resistance to the neuraminidase inhibitor oseltamivir limits the treatment of acute influenza infections. Targeting influenza virus-host interactions is a new and emerging field, and therapies based on the combination of virus- and host-directed drugs might significantly improve treatment success. We therefore assessed the combined treatment with oseltamivir and the repurposed antifungal drug itraconazole on infection of polarized broncho-epithelial Calu-3 cells with pdm09 or Panama influenza A virus strains. We detected significantly stronger antiviral activities in the combined treatment compared to monotherapy with oseltamivir, permitting lower concentrations of the drug than required for the single treatments. Bliss independence drug interaction analysis indicated that both drugs acted independently of each other. The additional antiviral effect of itraconazole might safeguard patients infected with influenza virus strains with heightened oseltamivir resistance.

Antifungal therapeutic drug monitoring: focus on drugs without a clear recommendation

BACKGROUND

The goal of therapeutic drug monitoring (TDM) is to determine the appropriate exposure of difficult-to-manage medications to optimize the clinical outcomes in patients in various clinical situations. Concerning antifungal treatment, and knowing that this procedure is expensive and time-consuming, TDM is particularly recommended for certain systemic antifungals: i.e., agents with a well-defined exposure-response relationship and unpredictable pharmacokinetic profile or narrow therapeutic index. Little evidence supports the routine use of TDM for polyenes (amphotericin B), echinocandins, fluconazole or new azoles such as isavuconazole, despite the fact that a better understanding of antifungal exposure may lead to a better response.

AIMS

The aim of this work is to review published pharmacokinetic/pharmacodynamic data on systemically administered antifungals, focusing on those for which monitoring is not routinely recommended by experts.

SOURCES

A MEDLINE search of the literature in English was performed introducing the following search terms: amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, triazoles, caspofungin, micafungin, anidulafungin, echinocandins, pharmacokinetics, pharmacodynamics, and therapeutic drug monitoring. Review articles and guidelines were also screened.

CONTENT

This review collects different pharmacokinetic/pharmacodynamic aspects of systemic antifungals and summarizes recent threshold values for clinical outcomes and adverse events. Although for polyenes, echinocandins, fluconazole and isavuconazole extensive clinical validation is still required for a clear threshold and a routine monitoring recommendation, particular points such as liposome structure or complex pathophysiological conditions affecting final exposure are discussed. For the rest, their better-defined exposure-response/toxicity relationships allow access to useful threshold values and to justify routine monitoring. Additionally, clinical data are needed to better define thresholds that can minimize the development of antifungal resistance.

IMPLICATIONS

General TDM for all systemic antifungals is not recommended; however, this approach may help to establish an adequate antifungal exposure for a favourable response, prevention of toxicity or development of resistance in special clinical circumstances.

Physiologically based pharmacokinetic modelling of oxycodone drug-drug interactions

Oxycodone is an opioid analgesic with several pharmacologically active metabolites and relatively narrow therapeutic index. Cytochrome P450 (CYP) 3A4 and CYP2D6 play major roles in the metabolism of oxycodone and its metabolites. Thus, inhibition and induction of these enzymes may result in substantial changes in the exposure of both oxycodone and its metabolites. In this study, a physiologically based pharmacokinetic (PBPK) model was built using GastroPlus™ software for oxycodone, two primary metabolites (noroxycodone, oxymorphone) and one secondary metabolite (noroxymorphone). The model was built based on literature and in house in vitro and in silico data. The model was refined and verified against literature clinical data after oxycodone administration in the absence of drug-drug interactions (DDI). The model was further challenged with simulations of oxycodone DDI with CYP3A4 inhibitors ketoconazole and itraconazole, CYP3A4 inducer rifampicin and CYP2D6 inhibitor quinidine. The magnitude of DDI (AUC ratio) was predicted within 1.5-fold error for oxycodone, within 1.8-fold and 1.3-4.5-fold error for the primary metabolites noroxycodone and oxymorphone, respectively, and within 1.4-4.5-fold error for the secondary metabolite noroxymorphone, when compared to the mean observed AUC ratios. This work demonstrated the capability of PBPK model to simulate DDI of the administered compounds and the formed metabolites of both DDI victim and perpetrator. However, the predictions for the formed metabolites tend to be associated with higher uncertainty than the predictions for the administered compound. The oxycodone model provides a tool for forecasting oxycodone DDI with other CYP3A4 and CYP2D6 DDI perpetrators that may be co-administered with oxycodone.

No Dose Adjustment for Isavuconazole Based on Age or Sex

This phase 1, open-label, single-dose, parallel-group study evaluated the pharmacokinetics (PK) of isavuconazole after a single oral dose of the prodrug isavuconazonium sulfate in healthy nonelderly (age, 18 to 45 years) and elderly (age, ≥65 years) males and females. Overall, 48 subjects were enrolled in the study (n = 12 each in groups of nonelderly males and females and elderly males and females).

This phase 1, open-label, single-dose, parallel-group study evaluated the pharmacokinetics (PK) of isavuconazole after a single oral dose of the prodrug isavuconazonium sulfate in healthy nonelderly (age, 18 to 45 years) and elderly (age, ≥65 years) males and females. Overall, 48 subjects were enrolled in the study (n = 12 each in groups of nonelderly males and females and elderly males and females). All subjects received a single oral dose of 372 mg of isavuconazonium sulfate (equivalent to 200 mg isavuconazole). PK samples were collected for analysis of isavuconazole plasma concentrations from the predose time point up to 336 h postdose. Data were analyzed using population pharmacokinetic (PPK) analysis. The resulting PPK model included two compartments with Weibull absorption function as well as interindividual variability with respect to clearance, intercompartment clearance, volumes of central and peripheral compartments, and two Weibull absorption parameters, RA and KAMAX. The PPK analysis showed that elderly females had the highest exposure versus males (ratio of total area under the time-concentration curve [AUC], 138; 90% confidence interval [CI], 118 to 161) and versus nonelderly females (ratio of AUC, 147; 90% CI, 123 to 176). Higher exposures in elderly females were not associated with significant toxicity or treatment-emergent adverse events, as measured in this study. No dose adjustments appear to be necessary based on either age group or sex even with an increase in exposure for elderly females. (This study has been registered at ClinicalTrials.gov under registration no. NCT01657890.)

Lipid Exchange Factors at Membrane Contact Sites in African Swine Fever Virus Infection

African swine fever (ASF) is a hemorrhagic fever of wild and domestic pigs with a high rate of mortality. Originally endemic in Africa, this disease is currently disseminating in Europe and China, causing a large socioeconomic impact. ASF is caused by a DNA virus, African swine fever virus (ASFV). There is no vaccine available against ASFV, limiting the options for disease control. ASFV reorganizes intracellular membranes to generate viral factories (VFs) in order to amplify its genome. However, little is known about the process involved in the formation of these viral replication organelles. Membrane contact sites (MCSs) allow nonvesicular lipids and ion exchange between organelles. Lipid exchange to form VFs apparently requires a number of proteins at MCSs, such as the oxysterol-binding protein (OSBP), the acyl-coenzyme A binding domain containing 3 (ACBD3) and the phosphatidylinositol-phosphate-4-kinase III beta (PI4Kβ). Itraconazole (ITZ) is an antifungal agent that targets sterol-transport molecules such as OSBP and OSBP-related protein 4 (ORP4). 25-Hydroxycholesterol (25-HC) inhibits lipid transport by high affinity binding OSBP. In this work, we analyzed the antiviral function of ITZ and 25-HC against ASFV in Vero cell cultures using the cell-adapted Ba71V isolate. ITZ and 25-HC decreased significantly ASFV replication. Our study revealed OSBP distribution in cytoplasmic membranes in uninfected Vero cells and to the periphery of VFs in infected cells. In addition, we showed that OSBP and OSBP-related proteins, PI4Kβ and ACBD3 were recruited to VFs in the context ASFV infection.

Itraconazole Dosing and Drug Monitoring at a Tertiary Children's Hospital

BACKGROUND

Itraconazole is a broad-spectrum antifungal agent used for prophylaxis and treatment of fungal infections in immunocompromised children. Achieving the recommended target serum itraconazole trough concentration of ≥0.5 mg/L is challenging in children because of variation in itraconazole pharmacokinetics with age. We studied itraconazole use and treatment outcomes in a tertiary children's hospital.

METHODS

We did a 10-year retrospective review of medical records of children at the Royal Children's Hospital Melbourne who received oral itraconazole and had therapeutic drug monitoring (TDM).

RESULTS

Overall, 81 children received 92 courses of oral itraconazole and had TDM. Of 222 TDM samples, 183 (82.4%) were taken at the appropriate time (trough level at steady state). Patients ≤12 and >12 years of age required median doses of 6.2 and 3.9 mg/kg/d, respectively, to attain target trough levels (P < 0.001). Of children ≤12 years of age, 71.4% required doses above the recommended dose of 5 mg/kg/d to achieve therapeutic levels, compared with 17.4% of those >12 years of age. At least 1 subtherapeutic trough concentration was reported in 63 (76.8%) courses; in only 18 (28.6%) of these was the dose adjusted. Gastrointestinal symptoms [14/92 (15.2%) courses] and hepatotoxicity [6/92 (6.5%)] were the most frequent adverse events. Neither was associated with elevated trough levels.

CONCLUSIONS

The poor attainment of target levels with current recommended dosing in children <12 years of age suggests that higher empiric doses are needed in this age group. The poor compliance with TDM guidelines highlights the need for better education about appropriate timing of sampling and dose adjustment.

The Fungal CYP51s: Their Functions, Structures, Related Drug Resistance, and Inhibitors

CYP51 (Erg11) belongs to the cytochrome P450 monooxygenase (CYP) superfamily and mediates a crucial step of the synthesis of ergosterol, which is a fungal-specific sterol. It is also the target of azole drugs in clinical practice. In recent years, researches on fungal CYP51 have stepped into a new stage attributing to the discovery of crystal structures of the homologs in Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. This review summarizes the functions, structures of fungal CYP51 proteins, and the inhibitors targeting these homologs. In particular, several drug-resistant mechanisms associated with the fungal CYP51s are introduced. The sequences and crystal structures of CYP51 proteins in different fungal species are also compared. These will provide new insights for the advancement of research on antifungal agents.

Pre-Existing Liver Disease and Toxicity of Antifungals

Pre-existing liver disease in patients with invasive fungal infections further complicates their management. Altered pharmacokinetics and tolerance issues of antifungal drugs are important concerns. Adjustment of the dosage of antifungal agents in these cases can be challenging given that current evidence to guide decision-making is limited. This comprehensive review aims to evaluate the existing evidence related to antifungal treatment in individuals with liver dysfunction. This article also provides suggestions for dosage adjustment of antifungal drugs in patients with varying degrees of hepatic impairment, after accounting for established or emerging pharmacokinetic–pharmacodynamic relationships with regard to antifungal drug efficacy in vivo.

Current state and outlook for drug repositioning anticipated in the field of ovarian cancer

Ovarian cancer is the seventh most common cancer and the eighth most common cause of cancer mortality in women. Although standard chemotherapy is the established treatment for ovarian cancer, the prognosis remains poor, and it is highly anticipated that new drugs will be developed. New drugs, such as humanized anti-vascular endothelial growth factor monoclonal antibodies and poly ADP-ribose polymerase inhibitors, are expected to improve clinical outcomes of ovarian cancer. However, long-term, costly research is required to develop such new drugs, and soaring national healthcare costs are becoming a concern worldwide. In this social context, drug repositioning, wherein existing drugs are used to develop drugs with new indications for other diseases, has recently gained attention. Because trials have already confirmed the safety in humans and the pharmacokinetics of such drugs, the development period is shorter than the conventional development of a new drug, thereby reducing costs. This review discusses the available basic experimental and clinical data on drugs used for other types of cancer for which drug repositioning is anticipated to repurpose the drug for the treatment of ovarian cancer. These include statins, which are used to treat dyslipidemia; bisphosphonate, which is used to treat osteoporosis; metformin, which is used to treat diabetes; non-steroidal anti-inflammatory drugs; ivermectin, an antiparasitic agent; and itraconazole, an anti-fungal agent. These drugs will play an important role in future drug repositioning strategies for ovarian cancer. Furthermore, drug repositioning is anticipated to extend not only to ovarian cancer treatment but also to ovarian cancer prevention.

Itraconazole inhibits proliferation of pancreatic cancer cells through activation of Bak-1

Itraconazole is an FDA-approved antifungal agent, which has been reported to possess promising anticancer activities in recent years. This study investigates the antiproliferative effects of itraconazole on pancreatic cancer cells and the molecular mechanism of its apoptosis-inducing effects. In this study, our results showed that itraconazole inhibited the growth of pancreatic cancer cells in vitro, and it also significantly inhibited the tumor growth of CFPAC-1 xenografts in vivo. Itraconazole induced apoptosis through ROS generation and mitochondrial membrane depolarization. A Bak-1 activation dependent apoptosis was identified in CFPAC-1 cells. These data suggested that itraconazole exhibited antiproliferative effects in pancreatic cancer cells by inducing apoptosis through Bak-1 activation.