Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition

Computational investigation of m-acetamide and 3MPAEA: Characterization, toxicity, and molecular docking and dynamic analyses

In this study, 2-(3-methoxyphenylamino)-2-oxoethyl acrylate (3MPAEA) molecule was synthesized in two steps. In the first step, 2-chloro-N-(3-methoxyphenyl)acetamide (m-acetamide) was obtained. Density functional theory (DFT) calculations were performed to obtain information about the electronic and structural properties of the synthesized molecules. The Raman Spectrum and UV-Visible analysis were calculated using the Gaussian package program. Additionally, Natural Bond Orbital (NBO) Analysis, Electron Localization Function (ELF), Electrostatic Potential Map (ESP), Average Local Ionization Energy (ALIE), and the toxicological properties of the molecules were examined. Simultaneously, molecular docking and dynamic analyses were conducted to investigate the interaction of m-acetamide and 3MPAEA with proteins involved in nuclear receptor signaling pathways, stress response pathways, molecular initiating events, and metabolism, as identified in the protox analysis. The findings aligned with the protox analysis results. The results obtained provide new insights into the electronic and toxicological properties of these molecules.

Artificial intelligence to predict inhibitors of drug-metabolizing enzymes and transporters for safer drug design

INTRODUCTION

Drug-metabolizing enzymes (DMEs) and transporters (DTs) play integral roles in drug metabolism and drug-drug interactions (DDIs) which directly impact drug efficacy and safety. It is well-established that inhibition of DMEs and DTs often leads to adverse drug reactions (ADRs) and therapeutic failure. As such, early prediction of such inhibitors is vital in drug development. In this context, the limitations of the traditional in vitro assays and QSAR models methods have been addressed by harnessing artificial intelligence (AI) techniques.

AREAS COVERED

This narrative review presents the insights gained from the application of AI for predicting DME and DT inhibitors over the past decade. Several case studies demonstrate successful AI applications in enzyme-transporter interaction prediction, and the authors discuss workflows for integrating these predictions into drug design and regulatory frameworks.

EXPERT OPINION

The application of AI in predicting DME and DT inhibitors has demonstrated significant potential toward enhancing drug safety and effectiveness. However, critical challenges involve the data quality, biases, and model transparency. The availability of diverse, high-quality datasets alongside the integration of pharmacokinetic and genomic data are essential. Lastly, the collaboration among computational scientists, pharmacologists, and regulatory bodies is pyramidal in tailoring AI tools for personalized medicine and safer drug development.

Rapid and sensitive HPLC with fluorescence detection method for quantifying selpercatinib in liver microsomes and rat plasma: Implications for drug-drug interaction studies

Selpercatinib (RETEVMO®) is a selective anticancer agent recently approved for thyroid and non-small cell lung cancer. Reliable analytical methods are essential for investigating its potential drug interactions. In this study, the fluorescence properties of selpercatinib were exploited for the first time to develop a sensitive high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method to quantify selpercatinib in human and rat liver microsomes and rat plasma. The method was successfully validated according to M10 guidelines demonstrating excellent accuracy, precision, selectivity, and sensitivity across a concentration range of (50-2000) ng/mL in plasma samples, with a short run time of less than 4 min. The method was applied to metabolic stability studies, where selpercatinib exhibited moderate intrinsic clearance (CLint) in human liver microsomes (CLint of 44.9 μL/min/mg), low clearance in female rat liver microsomes (CLint 10.6 μL/min/mg), and nearly no depletion in male rat liver microsomes. After treatment with dexamethasone, the clearance of selpercatinib was enhanced in both female and male rat liver microsomes, suggesting potential drug-drug interaction. Dexamethasone-treated female rat liver microsomes showed clearance similar to human liver microsomes, indicating their suitability as a surrogate model for studying human metabolism in vitro. Additionally, the inhibitory effect of myricetin on selpercatinib metabolism was comparable in both human and dexamethasone-treated female rat liver microsomes, with IC50 values of 9.3 μM and 10.9 μM, respectively. These findings suggest the need to investigate these potential drug interactions in clinical settings, as they may affect selpercatinib efficacy and toxicity. This HPLC-FLD method offers a rapid, sensitive, and cost-effective alternative to LC-MS/MS for studying pharmacokinetics in various in vitro and in vivo models.

Evidence-based guidelines for the pharmacological treatment of migraine

We here present evidence-based guidelines for the pharmacological treatment of migraine. These guidelines, created by the Italian Society for the Study of Headache and the International Headache Society, aim to offer clear, actionable recommendations to healthcare professionals. They incorporate evidence-based recommendations from randomized controlled trials and expert-based opinions. The guidelines follow the Grading of Recommendations, Assessment, Development and Evaluation approach for assessing the quality of evidence. The guideline development involved a systematic review of literature across multiple databases, adherence to Cochrane review methods, and a structured framework for data extraction and interpretation. Although the guidelines provide a robust foundation for migraine treatment, they also highlight gaps in current research, such as the paucity of head-to-head drug comparisons and the need for long-term outcome studies. These guidelines serve as a resource to standardize migraine treatment and promote high-quality care across different healthcare settings.

From closed to open: three dynamic states of membrane-bound cytochrome P450 3A4

Cytochrome P450 3A4 (CYP3A4) is a membrane bound monooxygenase. It metabolizes the largest proportion of all orally ingested drugs. Ligands can enter and exit the enzyme through flexible tunnels, which co-determine CYP3A4's ligand promiscuity. The flexibility can be represented by distinct conformational states of the enzyme. However, previous state definitions relied solely on crystal structures. We employed conventional molecular dynamics (cMD) simulations to sample the conformational space of CYP3A4. Five conformationally different crystal structures embedded in a membrane were simulated for 1 µs each. A Markov state model (MSM) coupled with spectral clustering (Robust Perron Cluster Analysis PCCA +) resulted in three distinct states: Two open conformations and an intermediate conformation. The tunnels inside CYP3A4 were calculated with CAVER3.0. Notably, we observed variations in bottleneck radii compared to those derived from crystallographic data. We want to point out the importance of simulations to characterize the dynamic behaviour. Moreover, we identified a mechanism, in which the membrane supports the opening of a tunnel. Therefore, CYP3A4 must be investigated in its membrane-bound state.

Trends in Precision Medicine and Pharmacogenetics as an Adjuvant in Establishing a Correct Immunosuppressive Therapy for Kidney Transplant: An Up-to-Date Historical Overview

Kidney transplantation is currently the treatment of choice for patients with end-stage kidney diseases. Although significant advancements in kidney transplantation have been achieved over the past decades, the host's immune response remains the primary challenge, often leading to potential graft rejection. Effective management of the immune response is essential to ensure the long-term success of kidney transplantation. To address this issue, immunosuppressives have been developed and are now fully integrated into the clinical management of transplant recipients. However, the considerable inter- and intra-patient variability in pharmacokinetics (PK) and pharmacodynamics (PD) of these drugs represents the primary cause of graft rejection. This variability is primarily attributed to the polymorphic nature (genetic heterogeneity) of genes encoding xenobiotic-metabolizing enzymes, transport proteins, and, in some cases, drug targets. These genetic differences can influence drug metabolism and distribution, leading to either toxicity or reduced efficacy. The main objective of the present review is to report an historical overview of the pharmacogenetics of immunosuppressants, shedding light on the most recent findings and also suggesting how relevant is the research and investment in developing validated NGS-based commercial panels for pharmacogenetic profiling in kidney transplant recipients. These advancements will enable the implementation of precision medicine, optimizing immunosuppressive therapies to improve graft survival and kidney transplanted patient outcomes.

Deep Learning Prediction of Drug-Induced Liver Toxicity by Manifold Embedding of Quantum Information of Drug Molecules

PURPOSE

Drug-induced liver injury, or DILI, affects numerous patients and also presents significant challenges in drug development. It has been attempted to predict DILI of a chemical by in silico approaches, including data-driven machine learning models. Herein, we report a recent DILI deep-learning effort that utilized our molecular representation concept by manifold embedding electronic attributes on a molecular surface.

METHODS

Local electronic attributes on a molecular surface were mapped to a lower-dimensional embedding of the surface manifold. Such an embedding was featurized in a matrix form and used in a deep-learning model as molecular input. The model was trained by a well-curated dataset and tested through cross-validations.

RESULTS

Our DILI prediction yielded superior results to the literature-reported efforts, suggesting that manifold embedding of electronic quantities on a molecular surface enables machine learning of molecular properties, including DILI.

CONCLUSIONS

The concept encodes the quantum information of a molecule that governs intermolecular interactions, potentially facilitating the deep-learning model development and training.

Roles of cytochromes P450 and ribosome inhibition in the interaction between two preoccupying mycotoxins, aflatoxin B1 and deoxynivalenol

Mycotoxins are a threat to human and animal health. Climate change increases their occurrence and our dietary exposure. Although humans and animals are concomitantly exposed to several mycotoxins, their combined effects are poorly characterised. This study investigated the interaction between aflatoxin B1 (AFB1), the most potent natural carcinogen, and deoxynivalenol (DON), which is among the most prevalent mycotoxins. AFB1 is associated with hepatocellular carcinoma through its bioactivation by cytochrome P450 (CYP450) enzymes; while DON induces ribotoxic stress leading to an alteration of intestinal, immune and hepatic functions. Analysis of DNA damage biomarkers γ-H2AX and 53BP1 revealed that DON reduces the genotoxicity of AFB1. This effect was mimicked with cycloheximide (CHX), another ribosome inhibitor; moreover DOM-1, a DON-derivative lacking ribosome inhibition, did not affect DNA damage. Exposure to DON, alone or in combination with AFB1, decreased the protein levels and/or activities of CYP1A2 and CYP3A4 in a time- and dose-dependent manner. A similar reduction of CYP1A2 and CYP3A4 activities was also observed with CHX. Altogether, these results revealed an original interaction between DON and AFB1, DON inhibiting the genotoxicity of AFB1. The underlying mechanism involves ribosome inhibition by DON and the subsequent impairment of CYP450s, responsible for the bioactivation of AFB1. This work highlights the importance of studying mycotoxins not only individually but also in mixture and of considering food contaminants as part of the exposome.

Deciphering Risk of Recurrent Bone Stress Injury in Female Runners Using Serum Proteomics Analysis and Predictive Models

Up to 40% of elite athletes experience bone stress injuries (BSIs), with 20-30% facing reinjury. Early identification of runners at high risk of subsequent BSI could improve prevention strategies. However, the complex etiology and multifactorial risk factors of BSIs makes identifying predictive risk factors challenging. In a study of 30 female recreational athletes with tibial BSIs, 10 experienced additional BSIs over a 1-year period, prompting investigation of systemic biomarkers of subsequent BSIs using aptamer-based proteomic technology. We hypothesized that early proteomic signatures could discriminate runners who experienced subsequent BSIs. 1,500 proteins related to metabolic, immune, and bone healing pathways were examined. Using supervised machine learning and genetic programming methods, we analyzed serum protein signatures over the 1-year monitoring period. Models were also created with clinical metrics, including standard-of-care blood analysis, bone density measures, and health histories. Protein signatures collected within three weeks of BSI diagnosis achieved the greatest separation by sparse partial least squares discriminant analysis (sPLS-DA), clustering single and recurrent BSI individuals with a mean accuracy of 96 ± 0.02%. Genetic programming models independently verified the presence of candidate biomarkers, including fumarylacetoacetase, osteopontin, and trypsin-2, which significantly outperformed clinical metrics. Time-course differential expression analysis highlighted 112 differentially expressed proteins in individuals with additional BSIs. Gene set enrichment analysis mapped these proteins to pathways indicating increased fibrin clot formation and decreased immune signaling in recurrent BSI individuals. These findings provide new insights into biomarkers and dysregulated protein pathways associated with recurrent BSI and may lead to new preventative or therapeutic intervention strategies.

One Sentence Summary

Our study identified candidate serum biomarkers to predict subsequent bone stress injuries in female runners, offering new insights for clinical monitoring and interventions.

Co-based carbon material as CYP3A4-like nanozyme with both biocatalytic activity and inhibition behaviors

Up to now, the biocatalytic activity of nanozymes has been extensively studied, while little research focus on their inhibitory behaviors. Here, Co-based carbon material (Co-DMOF) containing abundant carboxylic acid groups was prepared, with defects introduced by COx escape during pyrolysis to achieve controllable activity. As a result, Co-DMOF exhibited biocatalytic activity similar to cytochrome P450 3A4 (CYP3A4) in the metabolism of 1,4-Dihydropyridine (1,4-DHP, a calcium channel blocker). Excitingly, studies on IC50 and drug-drug interaction (DDI) suggested that Co-DMOF had similar inhibitory behaviors to CYP3A4. Moreover, Co-DMOF displayed excellent stability even under high temperature (100 °C), organic solvents, and a wide range of pH (4-9). Additionally, it can be reused for at least 7 times with only slight loss of activity. Therefore, Co-DMOF has great potential to become a low-cost alternative to CYP3A4 for drug dosage guideline, drug metabolism and DDI. This work provides more possibilities for expanding the CYP3A4-like nanozyme library.

Myopathy in Statin-Treated Children and Adolescents: A Practical Approach

PURPOSE OF REVIEW

This paper reviews the existing literature on statin-related myopathy in children and adolescents, to inform development of a practical management approach.

RECENT FINDINGS

Reports of statin treatment in the pediatric population revealed no evidence of muscle pathology, with asymptomatic elevation of creatine kinase(CK) levels and symptoms of muscle pain without CK elevation seen equally in subjects and controls in RCTs. By contrast, rare cases of rhabdomyolysis have now been documented in statin-treated children; this serious problem had never been previously reported. Statin-induced myopathy is rare in childhood so routine monitoring of CK levels is unnecessary in asymptomatic patients, reserved for those with muscle pain. Rare case reports of rhabdomyolysis in statin-treated children and adolescents suggest that parent and patient education on symptoms of adverse statin effects should include immediate physician contact with the appearance of dark urine, with or without muscle pain.

Asoprisnil as a Novel Ligand Interacting with Stress-Associated Glucocorticoid Receptor

Background/objective: The glucocorticoid receptor (GR) is critical in regulating cortisol production during stress. This makes it a key target for treating conditions associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation, such as mental disorders. This study explores novel ligands beyond mifepristone for their potential to modulate GR with improved efficacy and safety. By investigating these interactions, we seek to identify new pharmacotherapeutic options for stress-related mental illness. Methods: The ligands asoprisnil, campestanol, and stellasterol were selected based on structural similarities to mifepristone (reference ligand) and evaluated for pharmacological and ADME (absorption, distribution, metabolism, and excretion) properties using the SwissADME database. Molecular docking with AutoDock 4.2.6 and molecular dynamics simulations were performed to investigate ligand-protein interactions with the human glucocorticoid receptor, and binding free energies were calculated using MMPBSA. Results: Pharmacokinetic analysis revealed that asoprisnil exhibited high gastrointestinal absorption and obeyed Lipinski's rule, while mifepristone crossed the blood-brain barrier. Toxicological predictions showed that mifepristone was active for neurotoxicity and immunotoxicity, while asoprisnil, campestanol, and stellasterol displayed lower toxicity profiles. Asoprisnil demonstrated the highest stability in molecular dynamics simulations, with the highest negative binding energy of -62.35 kcal/mol, when compared to mifepristone, campestanol, and stellasterol, with binding energies of -57.08 kcal/mol, -49.99 kcal/mol, and -46.69 kcal/mol, respectively. Conclusion: This makes asoprisnil a potentially favourable therapeutic candidate compared to mifepristone. However, further validation of asoprisnil's interaction, efficacy, and safety in stress-related mental disorders through experimental studies and clinical trials is needed.

Systematic evaluation of therapeutic effectiveness of Azvudine in treating COVID-19 hospitalized patients: a retrospective cohort study

Background

Azvudine, a repurposed oral small molecule antiviral drug, has potential effects in combating the SARS-CoV-2 virus. However, studies on its clinical efficacy in patients with COVID-19 are still limited and controversial, and further research and validation are necessary.

Methods

A retrospective cohort study was conducted on COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command from 1 December 2022 to 31 January 2023. We included 132 patients treated with Azvudine and 132 controls after screening and propensity score matching. The primary outcomes including all-cause mortality and a composite outcome of disease progression such as non-invasive respiratory support, invasive respiratory support, admission to intensive care unit (ICU), and death were compared.

Results

Azvudine recipients had a much lower incidence rate of composite disease progression outcome than controls (13.9075/1000 person-days versus 25.7731/1000 person-days, P<0.05). Azvudine recipients also possessed a lower all-cause mortality rate than controls (2.6797/1000 person-days versus 8.5910/1000 person-days, P<0.01). Azvudine treatment significantly reduced the risk of composite disease progression (HR: 0.37, 95% CI: 0.16-0.84, P=0.017) and all-cause death (HR: 0.25, 95% CI: 0.08-0.81, P=0.021) after adjusting potential confounding factors such as age, sex, severity of COVID-19, complications, concomitant therapy, time from symptoms to treatment, and important laboratory indicators. The subgroup analyses of composite disease progression outcome and all-cause death indicated robustness of Azvudine's in treating COVID-19 patients in general.

Conclusion

Our study demonstrates that Azvudine has a significant positive impact on the clinical recovery of hospitalized patients with COVID-19. These findings provide important support for the use of Azvudine as a therapeutic option for COVID-19, given the current divergent views on its therapeutic efficacy and its importance in public health and medical care.

QTc Interval Prolongation as an Adverse Event of Azole Antifungal Drugs: Case Report and Literature Review

QTc prolongation and torsade de pointes (TdP) are significant adverse events linked to azole antifungals. Reports on QTc interval prolongation caused by these agents are limited. In this study, we report a case of a 77-year-old male with cardiovascular disease who experienced QTc prolongation and subsequent TdP while being treated with fluconazole for Candida albicans-induced knee arthritis. Additionally, a literature review was conducted on cases where QTc prolongation and TdP were triggered as adverse events of azole antifungal drugs. The case study detailed the patient's experience, whereas the literature review analyzed cases from May 1997 to February 2023, focusing on patient demographics, underlying diseases, antifungal regimens, concurrent medications, QTc changes, and outcomes. The review identified 16 cases, mainly in younger individuals (median age of 29) and women (75%). Fluconazole (63%) and voriconazole (37%) were the most common agents. Concurrent medications were present in 75% of cases, and TdP occurred in 81%. Management typically involved discontinuing or switching antifungals and correcting electrolytes, with all patients surviving. Risk assessment and concurrent medication review are essential before starting azole therapy. High-risk patients require careful electrocardiogram monitoring to prevent arrhythmias. Remote monitoring may enhance safety for patients with implanted devices. Further studies are needed to understand risk factors and management strategies.

Expert Consensus on the Management of Adverse Events of Lorlatinib in the Treatment of ALK+ Advanced Non-small Cell Lung Cancer

The use of anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs), such as lorlatinib, for the treatment of patients with ALK gene rearrangement (or ALK-positive) non-small cell lung cancer (NSCLC) has been shown to improve the overall survival and quality of life of these patients. However, lorlatinib is not exempt from potential adverse events. Adequate monitoring and management of these adverse events are critical for increasing patient adherence to lorlatinib, thereby maximizing the benefits of treatment and minimizing the risks associated with treatment discontinuation. Considering that the adverse events of lorlatinib can affect different organs and systems, the participation of a multidisciplinary team, including cardiologists, neurologists, internal medicine specialists, and oncology pharmacists, is needed. This article presents specific and pragmatic strategies for identifying and treating the most relevant adverse events associated with lorlatinib in patients with advanced ALK-positive NSCLC based on the clinical experience of a multidisciplinary panel of experts.

A Real-world Toxicity Atlas Shows that Adverse Events of Combination Therapies Commonly Result in Additive Interactions

PURPOSE

Combination therapies are a promising approach for improving cancer treatment, but it is challenging to predict their resulting adverse events in a real-world setting.

EXPERIMENTAL DESIGN

We provide here a proof-of-concept study using 15 million patient records from the FDA Adverse Event Reporting System (FAERS). Complex adverse event frequencies of drugs or their combinations were visualized as heat maps onto a two-dimensional grid. Adverse event frequencies were shown as colors to assess the ratio between individual and combined drug effects. To capture these patterns, we trained a convolutional neural network (CNN) autoencoder using 7,300 single-drug heat maps. In addition, statistical synergy analyses were performed on the basis of BLISS independence or χ2 testing.

RESULTS

The trained CNN model was able to decode patterns, showing that adverse events occur in global rather than isolated and unique patterns. Patterns were not likely to be attributed to disease symptoms given their relatively limited contribution to drug-associated adverse events. Pattern recognition was validated using trial data from ClinicalTrials.gov and drug combination data. We examined the adverse event interactions of 140 drug combinations known to be avoided in the clinic and found that near all of them showed additive rather than synergistic interactions, also when assessed statistically.

CONCLUSIONS

Our study provides a framework for analyzing adverse events and suggests that adverse drug interactions commonly result in additive effects with a high level of overlap of adverse event patterns. These real-world insights may advance the implementation of new combination therapies in clinical practice.

Cytochrome p450 and innovative nutraceutical products

Dietary supplements are products that are ingested in addition to the regular diet to provide additional health-promoting nutrients. Dietary supplements are defined and regulated differently in the European Union (EU) and the United States (US). A fundamental aspect, besides the one related to the composition of the various products on the market, is linked to their quality, both from a nutritional and a pharmacological point of view. Concerning the knowledge of the metabolic aspects, the analysis of the interference, as an inductive or an inhibitory effect, of the p450 enzyme on individual preparations of supplements, is crucial. In this study, we present the results of the interference analysis of a new nutraceutical product based on 38% Bergamot Polyphenolic Fraction BPF® (Citrus bergamia Risso et Poit.), Pomegranate (Punica granatum) and Citrus fruits (Citrus aurantium var. dulcis, Citrus maxima Burm. Merr, Citrus paradisi Macfad) extract with cytochrome p450, showing that the product has limited activity on the cytochromes involved in most of human drug metabolism. This nutraceutical product is to be considered safe and potentially useful in the context of multiple treatments, not interfering with the traditional chronic therapies of patients. These findings open the door to modern "pharma-grade" nutraceuticals, expanding the safety and quality profiles of these new products.

Chelerythrine Chloride is an Affinity-Labeling Inactivator of CYP3A4 by Modification of Cysteine239

Chelerythrine chloride (CHE) is a quaternary benzo[c]phenanthridine alkaloid with an iminium group that was found to cause time- and concentration-dependent inhibition of CYP3A4. The loss of CYP3A4 activity was independent of NADPH. CYP3A4 competitive inhibitor ketoconazole and nucleophile N-acetylcysteine (NAC) slowed the inactivation. No recovery of CYP3A4 activity was observed after dialysis. Dihydrochelerythrine hardly inhibited CYP3A4, suggesting that the iminium group was primarily responsible for the inactivation. UV spectral analysis revealed that the maximal absorbance of CHE produced a significant red-shift after being mixed with NAC, suggesting that 1,2-addition possibly took place between the sulfhydryl group of NAC and iminium group of CHE. Molecular dynamics simulation and site-direct mutagenesis studies demonstrated that modification of Cys239 by the iminium group of CHE attributed to the inactivation. In conclusion, CHE is an affinity-labeling inactivator of CYP3A4. The observed enzyme inactivation resulted from the modification of Cys239 of CYP3A4 by the iminium group of CHE.

The effect of genetic variants in the transcription factor TSPYL family on the CYP3A4 mediated cyclosporine metabolism in kidney transplant patients

CYP3A4 activity shows considerable interindividual variability. Although studies indicate 60%-80% is heritable, common single nucleotide variants (SNVs) in CYP3A4 together only explain ~10%. Transcriptional factors, such as the testis-specific Y-encoded-like proteins (TSPYLs) family, have been reported to regulate the expression of CYP enzymes including CYP3A4 in vitro. Here, we investigated the effect of genetic variants in TSPYL on CYP3A4 activity using data from a clinical study and a human liver bank. Five SNVs (rs3828743, rs10223646, rs6909133, rs1204807, and rs1204811) in TSPYL were selected because of a reported effect on CYP3A4 expression in vitro or suggested clinical effect. For the clinical study, whole blood concentrations, clinical data, and DNA were available from 295 kidney transplant recipients participating in the prospective MECANO study. A multivariate pharmacokinetic model adjusted for body weight, steroid treatment, and CYP3A4 genotype was used to assess the effect of the genetic variants on cyclosporine clearance. In multivariate analysis, homozygous carriers of rs3828743 had a 18% lower cyclosporin clearance compared to the wild-type and heterozygous patients (28.72 vs. 35.03 L/h, p = 0.018) indicating a lower CYP3A4 activity and an opposite direction of effect compared to the previously reported increased CYP3A4 expression. To validate, we tested associations between rs3828743 and CYP3A4 mRNA and protein expression as well as enzyme activity with data from a liver bank (n = 150). No association with any of these end points was observed. In conclusion, the totality of evidence is not in support of a significant role for TSPYL SNV rs3828743 in explaining variability in CYP3A4 activity.

Exploring Drug-Drug Interactions between Losartan and Carbamazepine: A Pharmacokinetic and Pharmacodynamic Study

BACKGROUND

Hypertension, which affects 1.28 billion people globally aged 30 to 79, is characterized by continuously high blood pressure (140/90 or more) and raises the risk of premature death. Losartan, an angiotensin receptor blocker (ARB), is suggested for patients under the age of 55 who cannot take ACE inhibitors as a first treatment option. Epilepsy, a chronic neurological illness marked by repeated seizures, affects more than 50 million individuals worldwide and is the third most common chronic brain disorder. Both hypertension and epilepsy are frequent chronic illnesses, with increased blood pressure greatly raising the risk of epilepsy due to its relationship with cerebrovascular disease, doubling the risk when compared to people with normal blood pressure.

OBJECTIVE

The effect on pharmacokinetics and pharmacodynamics of losartan on concomitant administration with carbamazepine was investigated.

MATERIALS AND METHODS

Wistar rats of either sex, with a minimum of six animals per group, were used in the investigation. The rats were treated with Losartan and Losartan-Carbamazepine for 30 days. Blood samples were taken via retro-orbital plexus at 0, 1, 2, 4, 6, and 12 hours after treatment concluded, and they were subjected to high-performance liquid chromatography for plasma analysis to calculate AUC, t1/2, and Clearance. A pharmacodynamic evaluation was done by inducing hypertension in rats using a 10% fructose solution and the effect of pretreated Losartan and Losartan-Carbamazepine on blood pressure was determined.

RESULTS

In the Losartan and Carbamazepine treated group, there was a reduction in the AUC and t1/2 and a reported increase in the clearance value compared to Losartan alone treated rats. In fructose-induced hypertension model to evaluate the effect of losartan and carbamazepine on BP showed an increase in mean arterial pressure, plasma glucose, and a reduction in triglycerides level was noted in comparison to Losartan alone treated rats indicating therapeutic failure of Losartan.

CONCLUSION

Based on these studies, it is concluded that CBZ has reduced the effectiveness of losartan and therefore, co-administration of these drugs should be avoided.

Association between potential supplement-drug interactions and liver diseases in patients with cancer: A large prospective cohort study

BACKGROUND & AIMS

The concurrent use of herbal and dietary supplements and conventional drugs can lead to interactions in patients with cancer, of which hepatotoxicity is one of the most concerning sequelae. This study examined the potential supplement-drug interactions involving the hepatic system, and their associations with documented liver diseases, among patients with cancer in a large population-based cohort in the UK Biobank.

METHODS

Participants diagnosed with cancer and had completed supplement-use assessment after diagnosis were included. Potentially interacting supplement-drug combinations that involved CYP enzymes or increased the risk of hepatotoxicity were identified from four tertiary databases. Liver diseases were identified using ICD-codes K70-77. Log-binomial regression was used to investigate the associations between potentially-interacting supplement-drug combinations and liver diseases documented (1) at any time, and (2) confined to only after the time of supplement-use assessment, adjusting for age, sex and pre-existing comorbidities.

RESULTS

This analysis included 30,239 participants (mean age = 60.0 years; 61.9% female). Over half (n = 17,698, 58.5%) reported the use of supplements after cancer diagnoses. Among supplements users, 36.9% (n = 6537/17,698) were on supplement-drug combinations with interacting potential involving the hepatic system. Patients taking supplements and drugs who had hepatic comorbidities were more likely to take potentially interacting pairs (adjusted risk ratio = 1.14, 95% CI = 1.06-1.23, p < 0.001). However, no significant association was observed between the use of these combinations and subsequent liver diseases (all p > 0.05).

CONCLUSION

Approximately one-third of the participants who had cancer and were supplement users had a risk of potential supplement-drug interactions that contribute to adverse liver effect. Healthcare professionals should communicate with patients with cancer, especially those with pre-existing liver diseases, about supplement use and proactively assess the clinical significance of potential interactions.

New Insights into the Nephroprotective Potential of Lercanidipine

Kidneys are responsible for many crucial biological processes in the human body, including maintaining the water-electrolyte balance, pH, and blood pressure (BP), along with the elimination of toxins. Despite this, chronic kidney disease (CKD), which affects more and more people, is a disease that develops insidiously without causing any symptoms at first. The main purpose of this article is to summarize the existing literature on lercanidipine, with a particular focus on its nephroprotective properties. Lercanidipine is a third-generation dihydropyridine (DHP) blocker of calcium channels, and as such it possesses unique qualities such as high lipophilicity and high vascular selectivity. Furthermore, it acts by reversibly inhibiting L-type and T-type calcium channels responsible for exerting positive renal effects. It has been shown to reduce tissue inflammation and tubulointerstitial fibrosis, contributing to a decrease in proteinuria. Moreover, it exhibited antioxidative effects and increased expression of molecules responsible for repairing damaged tissues. It also decreased cell proliferation, preventing thickening of the vascular lumen. This article summarizes studies simultaneously comparing the effect of lercanidipine with other antihypertensive drugs. There is still a lack of studies on the medications used in patients with CKD, and an even greater lack of studies on those used in patients with concomitant hypertension. Therefore, further studies on lercanidipine and its potential in hypertensive patients with coexisting CKD are required.

Synthesis and biological evaluation of coumarin derivatives as selective CYP2A6 inhibitors

Cytochrome P450 2A6 (CYP2A6) inhibitors are expected to be suitable as smoking cessation aids and for cancer prevention. Because the typical coumarin-based CYP2A6 inhibitor methoxsalen also inhibits CYP3A4, unintended drug-drug interactions are still a concern. Therefore, the development of selective CYP2A6 inhibitors is desirable. In this study, we synthesized coumarin-based molecules, determined the IC₅₀ values for CYP2A6 inhibition, verified the possibility of mechanism-based inhibition, and compared the selectivity for CYP2A6 versus CYP3A4. The results demonstrated that we developed CYP2A6 inhibitors that were more potent and selective than methoxsalen.

Dynamic Ir(III) Photosensors for the Major Human Drug-Metabolizing Enzyme Cytochrome P450 3A4

Probing the activity of cytochrome P450 3A4 (CYP3A4) is critical for monitoring the metabolism of pharmaceuticals and identifying drug-drug interactions. A library of Ir(III) probes that detect occupancy of the CYP3A4 active site were synthesized and characterized. These probes show selectivity for CYP3A4 inhibition, low cellular toxicity, Kd values as low as 9 nM, and are highly emissive with lifetimes up to 3.8 μs in cell growth media under aerobic conditions. These long emission lifetimes allow for time-resolved gating to distinguish probe from background autofluorescence from growth media and live cells. X-ray crystallographic analysis revealed structure-activity relationships and the preference or indifference of CYP3A4 toward resolved stereoisomers. Ir(III)-based probes show emission quenching upon CYP3A4 binding, then emission increases following displacement with CYP3A4 inhibitors or substrates. Importantly, the lead probes inhibit the activity of CYP3A4 at concentrations as low as 300 nM in CYP3A4-overexpressing HepG2 cells that accurately mimic human hepatic drug metabolism. Thus, the Ir(III)-based agents show promise as novel chemical tools for monitoring CYP3A4 active site occupancy in a high-throughput manner to gain insight into drug metabolism and drug-drug interactions.

Population pharmacokinetics of ruxolitinib in children with hemophagocytic lymphohistiocytosis: focus on the drug-drug interactions

PURPOSE

The optimal dose regimen of ruxolitinib (RUX) in children with hemophagocytic lymphohistiocytosis (HLH) remains to be determined. The aim was to develop and verify a population pharmacokinetic (PPK) model, and then provide references for the optimization of dose regimen of RUX in children with HLH.

METHODS

A total of 189 RUX concentrations from 32 children were included. The PPK model was established using the nonlinear mixed-effects model approach. Predictive performance and stability of the final PPK model were evaluated. The exposure of RUX in different clinical scenarios was simulated through Monte Carlo simulations.

RESULTS

A one-compartment model with first-order absorption and linear elimination was identified to describe the disposition of RUX. The absorption rate constant (K_a) in the final PPK model was 1.05 h^-1, and the apparent clearance (CL/F) and volume of distribution (V/F) were 9.80 L/h and 30.6 L, respectively. Coadministration with triazoles (TZS) and azithromycin (AZM) resulted in approximately 31.0% and 32.4% reductions in the CL/F of RUX, respectively. Multiple evaluation procedures showed satisfactory predictive performance and stability of the final model. Monte Carlo simulations showed that the exposure of RUX was significantly affected by the coadministration with TZS and/or AZM under different clinical scenarios.

CONCLUSION

For the first time, a PPK model of RUX in children with HLH was developed and evaluated. The coadministration with TZS and/or AZM were found to reduce the clearance of RUX in children. These findings could provide new insights for the precise treatment of RUX in children with HLH.

Relationship between clock gene expression and CYP2C19 and CYP3A4 with benzodiazepines

The present study aimed to clarify the expressions and roles of clock genes involved in drug metabolism in patients taking benzodiazepines (BZDs), as well as the drug metabolism regulators controlled by clock genes for each BZD type. The relationships between the expressions of the clock genes BMAL1, PER2, and DBP and the drug-metabolizing enzymes CYP3A4 and CYP2C19 were investigated using livers from BZD-detected autopsy cases. In addition, the effect of BZD exposure on various genes was examined in HepG2 human hepatocellular carcinoma cells. The expressions of DBP, CYP3A4, and CYP2C19 in the liver were lower in the diazepam-detected group than in the non-detected group. Furthermore, BMAL1 expression correlated with CYP2C19 expression. Cell culture experiments showed that the expressions of DBP and CYP3A4 decreased, whereas those of BMAL1 and CYP2C19 increased after diazepam and midazolam exposure. The results of the analyses of autopsy samples and cultured cells suggested that DBP regulates CYP3A4 when exposed to BZD. Understanding the relationship between these clock genes and CYPs may help achieve individualized drug therapy.

Characterisation of AMB-FUBINACA metabolism and CB1-mediated activity of its acid metabolite

PURPOSE

AMB-FUBINACA is a synthetic cannabinoid receptor agonist (SCRA) which is primarily metabolised by hepatic enzymes producing AMB-FUBINACA carboxylic acid. The metabolising enzymes associated with this biotransformation remain unknown. This study aimed to determine if AMB-FUBINACA metabolism could be reduced in the presence of carboxylesterase (CES) inhibitors and recreational drugs commonly consumed with it. The affinity and activity of the AMB-FUBINACA acid metabolite at the cannabinoid type-1 receptor (CB₁) was investigated to determine the activity of the metabolite.

METHODS

The effect of CES1 and CES2 inhibitors, and delta-9-tetrahydrocannabinol (Δ⁹-THC) on AMB-FUBINACA metabolism were determined using both human liver microsomes (HLM) and recombinant carboxylesterases. Radioligand binding and cAMP assays comparing AMB-FUBINACA and AMB-FUBINACA acid were carried out in HEK293 cells expressing human CB₁.

RESULTS

AMB-FUBINACA was rapidly metabolised by HLM in the presence and absence of NADPH. Additionally, CES1 and CES2 inhibitors both significantly reduced AMB-FUBINACA metabolism. Furthermore, digitonin (100 µM) significantly inhibited CES1-mediated metabolism of AMB-FUBINACA by ~ 56%, while the effects elicited by Δ⁹-THC were not statistically significant. AMB-FUBINACA acid produced only 26% radioligand displacement consistent with low affinity binding. In cAMP assays, the potency of AMB-FUBINACA was ~ 3000-fold greater at CB₁ as compared to the acid metabolite.

CONCLUSIONS

CES1A1 was identified as the main hepatic enzyme responsible for the metabolism of AMB-FUBINACA to its less potent carboxylic acid metabolite. This biotransformation was significantly inhibited by digitonin. Since other xenobiotics may also inhibit similar SCRA metabolic pathways, understanding these interactions may elucidate why some users experience high levels of harm following SCRA use.

Computational identification of potential inhibitory compounds in Indian medicinal and aromatic plant species against major pathogenicity determinants of SARS-CoV-2

SARS-CoV-2 (COVID-19) viral pandemic has been reported across 223 countries and territories. Globalized vaccination programs alongside administration of repurposed drugs will assumingly confer a stronger and longer individual specific immune protection. However, considering possible recurrence of the disease via new variants, a conveniently deliverable phytopharmaceutical drug might be the best option for COVID-19 treatment. In the current study, the efforts have been made to identify potential leads for inhalation therapy as nasal swabs have been reported to transfer viral load prominently. In that direction, 2363 Essential oil (EOs) compounds from Indian medicinal and aromatic plants were screened through docking analysis and potential candidates were shortlisted that can interfere with viral pathogenicity. The main protease (M^pro) of SARS-CoV-2 interacted closely with jatamansin (JM), 6,7-dehydroferruginol (FG) and beta-sitosterol (BS), while Papain-like Protease (PL^pro) with friedelane-3-one (F3O) and lantadene D (LD) independently. Reduced Lantadene A (LAR) exhibited preferable interaction with RNA-dependent-RNA-polymerase (RdRp) whereas Lantadene A (LA) with RdRp and spike-glycoprotein (SG-pro) both target proteins. When compared against highest binding affinity conformations of well-known inhibitors of targets, these prioritized compounds conferred superior or comparable SARS-CoV-2 protein inhibition. Additionally, promising results were noted from pharmacokinetics prediction for all shortlisted compounds. Besides, molecular dynamics simulation for 100 ns in two replicates and binding free energy analysis revealed the stability of complexes with optimum compactness. To the best of our knowledge, the current investigation is a unique initial attempt whereby EO compounds have been computationally screened, irrespective of their known medicinal properties to fight COVID-19 infection.Communicated by Ramaswamy H. Sarma.

What Is Known about Midazolam? A Bibliometric Approach of the Literature

Midazolam is a drug with actions towards the central nervous system producing sedative and anticonvulsants effects, used for sedation and seizures treatments. A better understanding about its effects in the different scenarios presented in the literature could be helpful to gather information regarding its clinical indications, pharmacological interactions, and adverse events. From this perspective, the aim of this study was to analyze the global research about midazolam mapping, specifically the knowledge of the 100 most-cited papers about this research field. For this, a search was executed on the Web of Science-Core Collection database using bibliometric methodological tools. The search strategy retrieved 34,799 articles. A total of 170 articles were evaluated, with 70 articles being excluded for not meeting the inclusion criteria. The 100 most-cited articles rendered 42,480 citations on WoS-CC, ranging from 253 to 1744. Non-systematic review was the most published study type, mainly from North America, during the period of 1992 to 2002. The most frequent keywords were midazolam and pharmacokinetics. Regarding the authors, Thummel and Kunze were the ones with the greatest number of papers included. Our findings showed the global research trends about midazolam, mainly related to its different effects and uses throughout the time.

Changes in Alprazolam Metabolism by CYP3A43 Mutants

Alprazolam is a triazolobenzodiazepine which is most commonly used in the short-term management of anxiety disorders, often in combination with antipsychotics. The four human members of the CYP3A subfamily are mainly responsible for its metabolism, which yields the main metabolites 4-hydroxyalprazolam and α-hydroxyalprazolam. We performed a comparison of alprazolam metabolism by all four CYP3A enzymes upon recombinant expression in the fission yeast Schizosaccharomyces pombe. CYP3A4 and CYP3A5 show the highest 4-hydroxyalprazolam production rates, while CYP3A5 alone is the major producer of α-hydroxyalprazolam. For both metabolites, CYP3A7 and CYP3A43 show lower activities. Computational simulations rationalize the difference in preferred oxidation sites observed between the exemplary enzymes CYP3A5 and CYP3A43. Investigations of the alprazolam metabolites formed by three previously described CYP3A43 mutants (L293P, T409R, and P340A) unexpectedly revealed that they produce 4-hydroxy-, but not α-hydroxyalprazolam. Instead, they all also make a different metabolite, which is 5-N-O alprazolam. With respect to 4-hydroxyalprazolam, the mutants showed fourfold (T409R) to sixfold (L293P and P340A) higher production rates compared to the wild-type (CYP3A43.1). In the case of 5-N-O alprazolam, the production rates were similar for the three mutants, while no formation of this metabolite was found in the wild-type incubation.

Important Drug-Drug Interactions for the Addiction Psychiatrist

The misuse of illicit substances, prescribed medications, and alcohol poses obvious health risks to afflicted individuals. When addressing these health risks, the overarching concerns generally relate to the direct effects that various substances can have on the functioning of multiple organ systems: cardiac, pulmonary, central nervous system, and others. What is not always evident, but potentially equally or even more dire, are the risks arising from drug-drug interactions involving illicit drugs and alcohol, whether with each other, or with prescribed medications. This review provides some basics that enable the reader to fruitfully approach the broad topic of drug-drug interactions.

Alprazolam-related deaths in Scotland, 2004-2020

BACKGROUND

The benzodiazepine drug alprazolam, a fast-acting tranquiliser, cannot be prescribed on the National Health Service in the United Kingdom. Illicit alprazolam supply and consumption have increased. Concern about increasing numbers of alprazolam-related fatalities started circulating in 2018. However, statistics on this issue are very limited. This study examined patterns in such mortality in Scotland.

METHODS

Statistics on deaths where alprazolam was mentioned in the 'cause of death' were obtained from official mortality registers. Anonymised Scottish case-level data were obtained. Data were examined in respect of the characteristics of decedents and deaths using descriptive statistics.

RESULTS

Scotland registered 370 deaths in 2004-2020; 366 of these occurred in 2015-2020: most involved males (77.1%); mean age 39.0 (SD 12.6) years. The principal underlying cause of death was accidental poisoning: opiates/opioids (77.9%); sedatives/hypnotics (15.0%). Two deaths involved alprazolam alone. Main drug groups implicated: opiates/opioids (94.8%), 'other benzodiazepines' (67.2%), gabapentinoids (42.9%), stimulants (30.1%), antidepressants (15.0%). Two-thirds (64.2%) involved combinations of central nervous system (CNS) depressants.

DISCUSSION

Alprazolam-related deaths are likely due to an increasing illicit supply. The fall in deaths in 2019-2020 is partially due to increased use of designer benzodiazepines. Treatment for alprazolam dependence is growing. Clinicians need to be aware of continuing recreational alprazolam use. When such consumption occurs with CNS depressants, overdose and death risks increase.

CONCLUSIONS

More awareness of alprazolam contributing to deaths, especially in conjunction with other CNS depressants, is needed by consumers and clinicians. Improved monitoring of illicit supplies could identify emerging issues of medicines' abuse.

Hepatic, Extrahepatic and Extracellular Vesicle Cytochrome P450 2E1 in Alcohol and Acetaminophen-Mediated Adverse Interactions and Potential Treatment Options

Alcohol and several therapeutic drugs, including acetaminophen, are metabolized by cytochrome P450 2E1 (CYP2E1) into toxic compounds. At low levels, these compounds are not detrimental, but higher sustained levels of these compounds can lead to life-long problems such as cytotoxicity, organ damage, and cancer. Furthermore, CYP2E1 can facilitate or enhance the effects of alcohol-drug and drug-drug interactions. In this review, we discuss the role of CYP2E1 in the metabolism of alcohol and drugs (with emphasis on acetaminophen), mediating injury/toxicities, and drug-drug/alcohol-drug interactions. Next, we discuss various compounds and various nutraceuticals that can reduce or prevent alcohol/drug-induced toxicity. Additionally, we highlight experimental outcomes of alcohol/drug-induced toxicity and potential treatment strategies. Finally, we cover the role and implications of extracellular vesicles (EVs) containing CYP2E1 in hepatic and extrahepatic cells and provide perspectives on the clinical relevance of EVs containing CYP2E1 in intracellular and intercellular communications leading to drug-drug and alcohol-drug interactions. Furthermore, we provide our perspectives on CYP2E1 as a druggable target using nutraceuticals and the use of EVs for targeted drug delivery in extrahepatic and hepatic cells, especially to treat cellular toxicity.

A multidimensional metabolomics workflow to image biodistribution and evaluate pharmacodynamics in adult zebrafish

An integrated evaluation of the tissue distribution and pharmacodynamic properties of a therapeutic is essential for successful translation to the clinic. To date, however, cost-effective methods to measure these parameters at the systems level in model organisms are lacking. Here, we introduce a multidimensional workflow to evaluate drug activity that combines mass spectrometry-based imaging, absolute drug quantitation across different biological matrices, in vivo isotope tracing and global metabolome analysis in the adult zebrafish. As a proof of concept, we quantitatively determined the whole-body distribution of the anti-rheumatic agent hydroxychloroquine sulfate (HCQ) and measured the systemic metabolic impacts of drug treatment. We found that HCQ distributed to most organs in the adult zebrafish 24 h after addition of the drug to water, with the highest accumulation of both the drug and its metabolites being in the liver, intestine and kidney. Interestingly, HCQ treatment induced organ-specific alterations in metabolism. In the brain, for example, HCQ uniquely elevated pyruvate carboxylase activity to support increased synthesis of the neuronal metabolite, N-acetylaspartate. Taken together, this work validates a multidimensional metabolomics platform for evaluating the mode of action of a drug and its potential off-target effects in the adult zebrafish. This article has an associated First Person interview with the first author of the paper.

Population-based signals of benzodiazepine drug interactions associated with unintentional traumatic injury

Benzodiazepine receptor agonists and related medications, such as Z-drugs and dual orexin receptor antagonists (BZDs), have been associated with unintentional traumatic injury due to their central nervous system (CNS)-depressant effects. Drug-drug interactions (DDIs) may contribute to the known relationship between BZD use and unintentional traumatic injury, yet evidence is still lacking. We conducted high-throughput pharmacoepidemiologic screening using the self-controlled case series design in a large US commercial health insurance database to identify potentially clinically relevant DDI signals among new users of BZDs. We used conditional Poisson regression to estimate rate ratios (RRs) between each co-exposure (vs. not) and unintentional traumatic injury (primary outcome), typical hip fracture (secondary outcome), and motor vehicle crash (secondary outcome). We identified 48 potential DDI signals (1.1%, involving 39 unique co-dispensed drugs), i.e., with statistically significant elevated adjusted RRs for injury. Signals were strongest for DDI pairs involving zolpidem, lorazepam, temazepam, alprazolam, eszopiclone, triazolam, and clonazepam. We also identified four potential DDI signals for typical hip fracture, but none for motor vehicle crash. Many signals have biologically plausible explanations through additive or synergistic pharmacodynamic effects of co-dispensed antidepressants, opioids, or muscle relaxants on CNS depression, impaired psychomotor and cognitive function, and/or somnolence. While other signals that lack an obvious mechanism may represent true associations that place patients at risk of injury, it is also prudent to consider the roles of chance, reverse causation, and/or confounding by indication, which merit further exploration. Given the high-throughput nature of our investigation, findings should be interpreted as hypothesis generating.

Preparation of Novel Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine Sulfonamides and Their Experimental and Computational Biological Studies

Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides constitute a novel class of heterocyclic compounds with broad biological activity, including anticancer properties. Investigated in this study, MM-compounds (MM134, MM136, MM137, and MM139) exhibited cytotoxic and proapoptotic activity against cancer cell lines (BxPC-3, PC-3, and HCT-116) in nanomolar concentrations without causing cytotoxicity in normal cells (L929 and WI38). In silico predictions indicate that tested compounds exhibit favorable pharmacokinetic profiles and may exert anticancer activity through the inhibition of BTK kinase, the AKT-mTOR pathway and PD1-PD-L1 interaction. Our findings point out that these sulfonamide derivatives may constitute a source of new anticancer drugs after optimization.

Quantification of the Time Course of CYP3A Inhibition, Activation, and Induction Using a Population Pharmacokinetic Model of Microdosed Midazolam Continuous Infusion

BACKGROUND

Cytochrome P450 (CYP) 3A contributes to the metabolism of many approved drugs. CYP3A perpetrator drugs can profoundly alter the exposure of CYP3A substrates. However, effects of such drug-drug interactions are usually reported as maximum effects rather than studied as time-dependent processes. Identification of the time course of CYP3A modulation can provide insight into when significant changes to CYP3A activity occurs, help better design drug-drug interaction studies, and manage drug-drug interactions in clinical practice.

OBJECTIVE

We aimed to quantify the time course and extent of the in vivo modulation of different CYP3A perpetrator drugs on hepatic CYP3A activity and distinguish different modulatory mechanisms by their time of onset, using pharmacologically inactive intravenous microgram doses of the CYP3A-specific substrate midazolam, as a marker of CYP3A activity.

METHODS

Twenty-four healthy individuals received an intravenous midazolam bolus followed by a continuous infusion for 10 or 36 h. Individuals were randomized into four arms: within each arm, two individuals served as a placebo control and, 2 h after start of the midazolam infusion, four individuals received the CYP3A perpetrator drug: voriconazole (inhibitor, orally or intravenously), rifampicin (inducer, orally), or efavirenz (activator, orally). After midazolam bolus administration, blood samples were taken every hour (rifampicin arm) or every 15 min (remaining study arms) until the end of midazolam infusion. A total of 1858 concentrations were equally divided between midazolam and its metabolite, 1'-hydroxymidazolam. A nonlinear mixed-effects population pharmacokinetic model of both compounds was developed using NONMEM^®. CYP3A activity modulation was quantified over time, as the relative change of midazolam clearance encountered by the perpetrator drug, compared to the corresponding clearance value in the placebo arm.

RESULTS

Time course of CYP3A modulation and magnitude of maximum effect were identified for each perpetrator drug. While efavirenz CYP3A activation was relatively fast and short, reaching a maximum after approximately 2-3 h, the induction effect of rifampicin could only be observed after 22 h, with a maximum after approximately 28-30 h followed by a steep drop to almost baseline within 1-2 h. In contrast, the inhibitory impact of both oral and intravenous voriconazole was prolonged with a steady inhibition of CYP3A activity followed by a gradual increase in the inhibitory effect until the end of sampling at 8 h. Relative maximum clearance changes were +59.1%, +46.7%, -70.6%, and -61.1% for efavirenz, rifampicin, oral voriconazole, and intravenous voriconazole, respectively.

CONCLUSIONS

We could distinguish between different mechanisms of CYP3A modulation by the time of onset. Identification of the time at which clearance significantly changes, per perpetrator drug, can guide the design of an optimal sampling schedule for future drug-drug interaction studies. The impact of a short-term combination of different perpetrator drugs on the paradigm CYP3A substrate midazolam was characterized and can define combination intervals in which no relevant interaction is to be expected.

CLINICAL TRIAL REGISTRATION

The trial was registered at the European Union Drug Regulating Authorities for Clinical Trials (EudraCT-No. 2013-004869-14).

Inhibition of Cytochrome P450 Enzymes by Drugs-Molecular Basis and Practical Applications

Drug-drug interactions are a major cause of hospitalization and deaths related to drug use. A large fraction of these is due to inhibition of enzymes involved in drug metabolism and transport, particularly cytochrome P450 (P450) enzymes. Understanding basic mechanisms of enzyme inhibition is important, particularly in terms of reversibility and the use of the appropriate parameters. In addition to drug-drug interactions, issues have involved interactions of drugs with foods and natural products related to P450 enzymes. Predicting drug-drug interactions is a major effort in drug development in the pharmaceutical industry and regulatory agencies. With appropriate in vitro experiments, it is possible to stratify clinical drug-drug interaction studies. A better understanding of drug interactions and training of physicians and pharmacists has developed. Finally, some P450s have been the targets of drugs in some cancers and other disease states.

Predicting the Drug-Drug Interaction Mediated by CYP3A4 Inhibition: Method Development and Performance Evaluation

The prediction of drug-drug interactions (DDIs) plays critical roles for the estimation of DDI risk caused by inhibition of CYP3A4. The aim of this paper is to develop a physiologically based pharmacokinetic (PBPK)-DDI model for prediction of the DDI co-administrated with ketoconazole in humans and evaluate the predictive performance of the model. The pharmacokinetic and biopharmaceutical properties of 35 approved drugs, as victims, were collected for the development of a PBPK model, which were linked to the PBPK model of ketoconazole for the DDI prediction. The PBPK model of victims and ketoconazole were validated by matching actual in vivo pharmacokinetic data. The predicted results of DDI were compared with actual data to evaluate the predictive performance. The percentage of predicted ratio of AUC (AUCR), C_max (C_maxR), and T_max (T_maxR) was 75%, 69%, and 91%, respectively, which were within the twofold threshold (range, 0.5-2.0×) of the observed values. Only 3% of the predicted AUCRs are obviously underestimated. After integration of the reported fraction of metabolism (f_m) into the PBPK-DDI model for limited four cases, the model-predicted AUCRs were improved from the twofold range of the observed AUCRs to the 90% confidence interval. The developed method could reasonably predict drug-drug interaction with a low risk of underestimation. The present accuracy of the prediction was improved compared with that of static mechanistic models. The evaluation of predictive performance increases the confidence using the model to evaluate the risk of DDIs co-administrated with ketoconazole before the in vivo DDI study.

P-Glycoprotein (ABCB1/MDR1) Controls Brain Penetration and Intestinal Disposition of the PARP1/2 Inhibitor Niraparib

Niraparib (Zejula), a selective oral PARP1/2 inhibitor registered for ovarian, fallopian tube, and primary peritoneal cancer treatment, is under investigation for other malignancies, including brain tumors. We explored the impact of the ABCB1 and ABCG2 multidrug efflux transporters, the OATP1A/1B uptake transporters, and the CYP3A drug-metabolizing complex on oral niraparib pharmacokinetics, using wild-type and genetically modified mouse and cell line models. In vitro, human ABCB1 and mouse Abcg2 transported niraparib moderately. Compared to wild-type mice, niraparib brain-to-plasma ratios were 6- to 7-fold increased in Abcb1a/1b^-/- and Abcb1a/1b;Abcg2^-/- but not in single Abcg2^-/- mice, while niraparib plasma exposure at later time points was ∼2-fold increased. Niraparib recovery in the small intestinal content was markedly reduced in the Abcb1a/1b-deficient strains. Pretreatment of wild-type mice with oral elacridar, an ABCB1/ABCG2 inhibitor, increased niraparib brain concentration and reduced small intestinal content recovery to levels observed in Abcb1a/1b;Abcg2^-/- mice. Oatp1a/1b deletion did not significantly affect niraparib oral bioavailability or liver distribution but decreased metabolite M1 liver uptake. No significant effects of mouse Cyp3a ablation were observed, but overexpression of transgenic human CYP3A4 unexpectedly increased niraparib plasma exposure. Thus, Abcb1 deficiency markedly increased niraparib brain distribution and reduced its small intestinal content recovery, presumably through reduced biliary excretion and/or decreased direct intestinal excretion. Elacridar pretreatment inhibited both processes completely. Clinically, the negligible role of OATP1 and CYP3A could be advantageous for niraparib, diminishing drug-drug interaction or interindividual variation risks involving these proteins. These findings may support the further clinical development and application of niraparib.

Risk assessment of the inhibition of hydroxygenkwanin on human and rat cytochrome P450 by cocktail method

Hydroxygenkwanin (HGK), a natural flavonoid extracted from the buds of Daphne genkwa Sieb.et Zucc. (Thymelaeaceae), possesses a wide range of pharmacological activities, including anti-inflammatory, antibacterial and anticancer. However, the inhibitory effect of HGK on cytochrome P450 (CYP) remains unclear. This study investigated the potential inhibitory effects of HGK on CYP1A2, 2B1/6, 2C9/11, 2D1/6, 2E1 and 3A2/4 enzymes in human and rat liver microsomes (HLMs and RLMs) by the cocktail approach. HGK exhibited no time-dependent inhibition of CYP activities in HLMs and RLMs. Enzyme inhibition kinetics indicated that HGK was not only a competitive inhibitor of human CYP1A2 and 2C9, but also competitively inhibited rat CYP1A2 and 2C11 activities, with K_i value at 0.84 ± 0.03, 8.09 ± 0.44, 2.68 ± 0.32 and 8.35 ± 0.31 μM, respectively. Further studies showed that the inhibitory effect of HGK on CYP enzymes was weaker than that of diosmetin, which may be related to the substitution of hydroxyl and methoxy in the A and B rings of the flavone skeleton. Therefore, the low K_i values of HGK for CYP1A2 and 2C may lead to potential drug-drug interactions and toxicity.

Evidence-Based Guidelines for Drug Interaction Studies: Model-Informed Time Course of Intestinal and Hepatic CYP3A4 Inhibition by Clarithromycin

Drug-drug interaction (DDI) studies are mandated in drug development; however, protocols for evaluating the impact of cytochrome P450 (CYP) inhibition on new molecular entities are currently inconsistent. This study utilised validated physiologically based pharmacokinetic (PBPK) software to define the optimal dose, frequency, and duration of clarithromycin to achieve optimal characterisation of CYP3A4 inhibition in a study population. The Simcyp® Simulator (Version 19.0) was used to simulate clarithromycin-mediated CYP3A4 inhibition in healthy virtual cohorts. Between trial variability in magnitude and time course of CYP3A4 activity was assessed following clarithromycin dosing strategies obtained from the University of Washington Drug Interaction Database. Heterogeneity in CYP3A4 inhibition was evaluated across sex, race, and age. Literature review identified 500 mg twice daily for 5 days as the most common clarithromycin dosing protocol for CYP3A4 inhibition studies. On simulation, clarithromycin 500 mg twice daily resulted in the largest steady-state inhibition of hepatic (percent mean inhibition [95%CI] = 80 [77-83]) and small intestine (94 [94-95]) CYP3A4 activity (as compared to 500 mg once daily, 400 mg once/twice daily, or 250 mg once/twice daily). Additionally, 500 mg twice daily was associated with the shortest time for 90% of individuals to reach 90% of their minimum hepatic (4 days) and small intestine (1 days) CYP3A4 activity. The study presented herein supports that clarithromycin dosing protocol of 500 mg twice daily for 5 days is sufficient to achieve maximal hepatic and small intestine CYP3A4 inhibition. These findings were consistent between sex, race, and age differences.

Clinical Significance and Integrative Analysis of the SMC Family in Hepatocellular Carcinoma

Worldwide, hepatocellular carcinoma (HCC) is one of the most malignant cancers with poor prognosis. The structural maintenance of chromosomes (SMC) gene family has been shown to play important roles in human cancers. Nevertheless, the role of SMC members in HCC is not well-understood. In this study, we comprehensively explored the role of the SMC family in HCC using a series of bioinformatic analysis tools. Studies have demonstrated that the mRNA expression levels of SMC1A, SMC1B, SMC2, SMC4, and SMC6 are significantly overexpressed in HCC, and the protein levels of SMC1A, SMC2, SMC3, SMC4, SMC5, and SMC6 are similarly elevated. Moreover, HCC patients with high SMC2 and SMC4 expression levels exhibit poor survival. Using KEGG and GO analyses, we analyzed the enrichment of gene expression in the biological functions and pathways of the SMC family in HCC. Immune infiltration analysis revealed that the expression of the SMC family is closely associated with B cells, CD4+ T cells, CD8+ T cells, macrophages, neutrophils, and DCs. In conclusion, our findings will enhance a more thorough understanding of the SMC family in HCC progression and provide new directions for the diagnosis and treatment of HCC in the future.

Nanoparticulate Drug Delivery Strategies to Address Intestinal Cytochrome P450 CYP3A4 Metabolism towards Personalized Medicine

Drug dosing in clinical practice, which determines optimal efficacy, toxicity or ineffectiveness, is critical to patients' outcomes. However, many orally administered therapeutic drugs are susceptible to biotransformation by a group of important oxidative enzymes, known as cytochrome P450s (CYPs). In particular, CYP3A4 is a low specificity isoenzyme of the CYPs family, which contributes to the metabolism of approximately 50% of all marketed drugs. Induction or inhibition of CYP3A4 activity results in the varied oral bioavailability and unwanted drug-drug, drug-food, and drug-herb interactions. This review explores the need for addressing intestinal CYP3A4 metabolism and investigates the opportunities to incorporate lipid-based oral drug delivery to enable precise dosing. A variety of lipid- and lipid-polymer hybrid-nanoparticles are highlighted to improve drug bioavailability. These drug carriers are designed to target different intestinal regions, including (1) local saturation or inhibition of CYP3A4 activity at duodenum and proximal jejunum; (2) CYP3A4 bypass via lymphatic absorption; (3) pH-responsive drug release or vitamin-B12 targeted cellular uptake in the distal intestine. Exploitation of lipidic nanosystems not only revives drugs removed from clinical practice due to serious drug-drug interactions, but also provide alternative approaches to reduce pharmacokinetic variability.

Main protease inhibitors and drug surface hotspots for the treatment of COVID-19: A drug repurposing and molecular docking approach

Here, drug repurposing and molecular docking were employed to screen approved MPP inhibitors and their derivatives to suggest a specific therapeutic agent for the treatment of COVID-19. The approved MPP inhibitors against HIV and HCV were prioritized, while RNA dependent RNA Polymerase (RdRp) inhibitor remdesivir including Favipiravir, alpha-ketoamide were studied as control groups. The target drug surface hotspot was also investigated through the molecular docking technique. Molecular dynamics was performed to determine the binding stability of docked complexes. Absorption, distribution, metabolism, and excretion analysis was conducted to understand the pharmacokinetics and drug-likeness of the screened MPP inhibitors. The results of the study revealed that Paritaprevir (-10.9 kcal/mol) and its analog (CID 131982844) (-16.3 kcal/mol) showed better binding affinity than the approved MPP inhibitors compared in this study, including remdesivir, Favipiravir, and alpha-ketoamide. A comparative study among the screened putative MPP inhibitors revealed that the amino acids T25, T26, H41, M49, L141, N142, G143, C145, H164, M165, E166, D187, R188, and Q189 are at potentially critical positions for being surface hotspots in the MPP of SARS-CoV-2. The top 5 predicted drugs (Paritaprevir, Glecaprevir, Nelfinavir, and Lopinavir) and the topmost analog showed conformational stability in the active site of the SARS-CoV-2 MP protein. The study also suggested that Paritaprevir and its analog (CID 131982844) might be effective against SARS-CoV-2. The current findings are limited to in silico analysis and lack in vivo efficacy testing; thus, we strongly recommend a quick assessment of Paritaprevir and its analog (CID 131982844) in a clinical trial.

One-component nano-metal-organic frameworks with superior multienzyme-mimic activities for 1,4-dihydropyridine metabolism

Although a number of nanozymes have been developed, it is still difficult to develop single-component nanozyme with overall high multienzyme-like activities. In this study, the nanosized metal-organic frameworks (nano-MOFs) FePCN (PCN stands for porous coordination network) was synthesized by integrating zirconium and iron ions with different catalytic property on single-component MOFs and exhibited superior intrinsic multienzyme-like activities, namely oxidase-, peroxidase- and phosphatase-mimicking activity. The catalytic active sites of oxidase- and peroxidase-, and phosphatase-like activity of FePCN were Fe-centers and Zr-O clusters, respectively. Based on the intrinsic oxidase-like activity and the similarity of molecular structures between cytochrome P450 oxidase (CYP) cofactors and the organic linker in FePCN, FePCN exhibited high CYP-like activity to catalyze the oxidation of hypotensive drug 1,4-dihydropyridine (1,4-DHP) into diethyl 2,6-dimethylpyridine-3,5-dicarboxylate (DDPD) and the yield of DDPD reached over 80%. Moreover, as peroxidase- and phosphatase-mimics, FePCN was successfully applied to detecting H₂O₂ under neutral condition and catalyzing the dephosphorylation of adenosine triphosphate (ATP), respectively. This study provides a feasible way for rational design one-component nanomaterials as multienzyme-mimics.

Changes in the Pharmacokinetics and Pharmacodynamics of Sildenafil in Cigarette and Cannabis Smokers

Sildenafil citrate, a widely-used oral therapy for erectile dysfunction, is a cytochrome P3A4 (CYP3A4) enzyme substrate. Studies have reported that this substrate has an inhibitory effect on CYP3A4 enzymes in long-term cigarette and cannabis smokers, which predominantly mediate the hepatic elimination of sildenafil. Cigarette and/or cannabis smoking could therefore alter the exposure of sildenafil. The aim of this study was to examine the effect of smoking cigarettes and/or cannabis on the pharmacokinetics, pharmacodynamics, safety and tolerability of sildenafil. Thirty-six healthy human subjects were equally divided into three groups: non-smokers, cigarette smokers and cannabis smokers. Each group was administered a single dose of sildenafil (50 mg tablets). The primary outcome measures included the maximum concentration of sildenafil in plasma (C_max), the elimination half-life (t1/2) and the area under the plasma concentration time curve from zero to time (AUC_0-t). The pharmacodynamics were assessed by the International Index of Erectile Function (IIEF-5). The exposure of sildenafil (AUC_0-t) showed a statistically significant increase in cigarette smokers (1156 ± 542 ng·h/mL) of 61% (p < 0.05) while in cannabis smokers (967 ± 262 ng·h/mL), a non-significant increase in AUC_0-t of 35% (p > 0.05) was observed relative to non-smokers (717 ± 311 ng·h/mL). Moreover, the C_max of sildenafil increased by 63% (p < 0.05) and 22% (p > 0.05) in cigarette smokers and cannabis smokers, respectively. Cigarette smoking increases the exposure of sildenafil to a statistically significant level with no effect on its pharmacodynamics, safety and tolerability.

Monitoring and Managing Lorlatinib Adverse Events in the Portuguese Clinical Setting: A Position Paper

Rearrangements in the anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) genes characterise two distinct molecular subsets of non-small cell lung cancer (NSCLC) tumours. Lorlatinib is a third-generation ALK/ROS1 tyrosine kinase inhibitor (TKI) shown to have systemic and intracranial activity in treatment-naive patients and in those who progressed on first- and second-generation TKIs. Despite being generally well tolerated, lorlatinib has a unique and challenging safety profile that includes hyperlipidaemia and central and peripheral nervous system adverse events (AEs). This article summarises a set of strategies designed to monitor and manage lorlatinib-related AEs that were agreed upon by a multidisciplinary panel of specialists in a meeting held in July 2020. Among the recommendations hereby described, special emphasis was placed on communication: prescribing physicians should inform patients and their families/caregivers about the likelihood and nature of lorlatinib AEs, encouraging them to report any symptoms, while at the same time reassuring them that most events are manageable and resolve spontaneously and have little to no interference with cancer treatment. Importantly, all patients should undergo a set of baseline assessments, including biochemical analysis, evaluation of cardiovascular risk, electrocardiogram (ECG), neurological evaluation and contrast-enhanced magnetic resonance imaging of the brain, which should be repeated regularly during lorlatinib treatment. Supportive medications to treat or relieve lorlatinib AEs were also discussed, as were the conditions requiring specialist consultations and/or adjustments in lorlatinib therapy. The overall goal of this article is to serve as a practical guide for oncologists to systematically and effectively approach lorlatinib AEs.

The Use of Bio-Active Compounds of Citrus Fruits as Chemopreventive Agents and Inhibitor of Cancer Cells Viability

Common therapy of cancer, such as chemotherapy, has various side effects for the patients. In recent studies, new therapeutic approaches in cancer treatment are adjuvant therapy, along with a reduction in side effects of chemotherapy drugs. Treatment by herbal medicines may have some advantages over treatment with single purified chemicals, also in terms of side effects, the use of plants in cancer treatment is a more secure method. Citrus fruits are one of the most consumed natural products in the world due to the presence of various metabolites and bioactive compounds, such as phenols, flavonoids and, carotenoids. Bioactive compounds of citrus modulate signaling pathways and interact with signaling molecules such as apoptotic and cell cycle (P53, P21, etc.) and thus have a wide range of pharmacological activities, including anti-inflammatory, anti-cancer and oxidative stress. The findings discussed in this review strongly support their potential as anti-cancer agents. Therefore, the purpose of this review was to examine the effects of active compounds in citrus as a therapy agent in cancer treatment.

Role of Pharmacogenetics in Adverse Drug Reactions: An Update towards Personalized Medicine

Adverse drug reactions (ADRs) are an important and frequent cause of morbidity and mortality. ADR can be related to a variety of drugs, including anticonvulsants, anaesthetics, antibiotics, antiretroviral, anticancer, and antiarrhythmics, and can involve every organ or apparatus. The causes of ADRs are still poorly understood due to their clinical heterogeneity and complexity. In this scenario, genetic predisposition toward ADRs is an emerging issue, not only in anticancer chemotherapy, but also in many other fields of medicine, including hemolytic anemia due to glucose-6-phosphate dehydrogenase (G6PD) deficiency, aplastic anemia, porphyria, malignant hyperthermia, epidermal tissue necrosis (Lyell's Syndrome and Stevens-Johnson Syndrome), epilepsy, thyroid diseases, diabetes, Long QT and Brugada Syndromes. The role of genetic mutations in the ADRs pathogenesis has been shown either for dose-dependent or for dose-independent reactions. In this review, we present an update of the genetic background of ADRs, with phenotypic manifestations involving blood, muscles, heart, thyroid, liver, and skin disorders. This review aims to illustrate the growing usefulness of genetics both to prevent ADRs and to optimize the safe therapeutic use of many common drugs. In this prospective, ADRs could become an untoward "stress test," leading to new diagnosis of genetic-determined diseases. Thus, the wider use of pharmacogenetic testing in the work-up of ADRs will lead to new clinical diagnosis of previously unsuspected diseases and to improved safety and efficacy of therapies. Improving the genotype-phenotype correlation through new lab techniques and implementation of artificial intelligence in the future may lead to personalized medicine, able to predict ADR and consequently to choose the appropriate compound and dosage for each patient.