Physiologically-based pharmacokinetic modeling to predict drug-drug interaction of enzalutamide with combined P-gp and CYP3A substrates

Effect of Danhong injection on pharmacokinetics and pharmacodynamics of rivaroxaban in rats

BACKGROUND AND OBJECTIVES

Rivaroxaban is often used in combination with DHI to treat thromboembolic disease. Whether the combination causing HDIs is still unknown. The purpose of this study was to evaluate effects of DHI on pharmacokinetics and pharmacodynamics of rivaroxaban in rats and effects on CYP3A2.

METHODS

Plasma concentration of rivaroxaban with or without DHI was determined by HPLC. Pharmacokinetics parameters were calculated. Effect of DHI on pharmacodynamics of rivaroxaban was investigated by APTT, PT, TT, FIB, INR, length of tail thrombosis, vWF, t-PA, PAI-1, IL-1β, TNF-α and histopathological sections. Effect of DHI on CYP3A2 in rats was investigated by probe drug method.

RESULTS

Cmax and AUC of rivaroxaban increased significantly in combination group (P < 0.05). APTT, PT, INR and TT increased (P < 0.05), length of tail thrombosis, FIB, vWF, PAI-1, IL-1β and TNF-α of combination group decreased significantly (P < 0.05) compared with rivaroxaban or DHI alone. Histopathologic section of tail thrombus had significant improvement. Cmax and AUC of dapsone increased (P < 0.05) in DHI group.

CONCLUSION

In summary, DHI is an inhibitor of CYP3A2 and could significantly affect pharmacokinetics and pharmacodynamic of rivaroxaban, enhance anticoagulant and antithrombotic efficacy in rats. However, the combination of rivaroxaban and DHI might lead to potential HDIs. The dosage of rivaroxaban should be adjusted in clinical.

Utility of physiologically based pharmacokinetic modeling in predicting and characterizing clinical drug interactions

Physiologically based pharmacokinetic (PBPK) modeling is a mechanistic dynamic modeling approach that can be used to predict or retrospectively describe changes in drug exposure due to drug-drug interactions (DDIs). With advancements in commercially available PBPK software, PBPK DDI modeling has become a mainstream approach from early drug discovery through to late-stage drug development and is often used to support regulatory packages for new drug applications. This Minireview will briefly describe the approaches to predicting DDI using PBPK and static modeling approaches, the basic model structures and features inherent to PBPK DDI models, and key examples where PBPK DDI models have been used to describe complex DDI mechanisms. Future directions aimed at using PBPK models to characterize transporter-mediated DDI, predict DDI in special populations, and assess the DDI potential of protein therapeutics will be discussed. A summary of the 209 PBPK DDI examples published to date in 2023 will be provided. Overall, current data and trends suggest a continued role for PBPK models in the characterization and prediction of DDI for therapeutic molecules. SIGNIFICANCE STATEMENT: Physiologically based pharmacokinetic (PBPK) models have been a key tool in the characterization of various pharmacokinetic phenomena, including drug-drug interactions. This Minireview will highlight recent advancements and publications around physiologically based pharmacokinetic drug-drug interaction modeling, an important area of drug discovery and development research in light of the increasing prevalence of polypharmacology in clinical settings.

Drug-drug interactions in HIV-infected patients receiving chemotherapy

INTRODUCTION

Coadministration of antiretrovirals and anti-cancer medications may present many complex clinical scenarios. This is characterized by the potential for drug-drug interactions (DDIs) and the challenges that arise in patient management. In this article, we investigate the potential for DDIs between antiretrovirals, including protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), integrase strand transfer inhibitors (INSTIs), and anti-cancer medications.

AREAS COVERED

PubMed, Google Scholar, and Clinicaltrials.gov were searched for relevant articles in April 2024. Our review highlights PIs and NNRTIs as particularly prone to DDIs with anticancer agents, with implications for efficacy and toxicity of concomitant cancer therapy. We explain the mechanisms for interactions, emphasizing the significance of pharmacokinetic effects and enzyme induction or inhibition. We discuss clinical challenges encountered in the management of patients receiving combined ART and cancer therapy regimens.

EXPERT OPINION

Data are lacking for potential DDIs between antiretroviral and anti-cancer agents. While some interactions are documented, others are theoretical and based on the pharmacokinetic properties of the medications. Awareness of these interactions, inter-collaborative care between healthcare providers, and standardized treatment guidelines are all crucial for achieving optimal treatment outcomes and ensuring the well-being of patients with HIV/AIDS and cancer comorbidities.

Androgen receptor pathway inhibitors and drug-drug interactions in prostate cancer

Prostate cancer represents a major global health challenge, necessitating efficacious therapeutic strategies. Androgen receptor pathway inhibitors (ARPIs) have become central to prostate cancer treatment, demonstrating significant effectiveness in both metastatic and non-metastatic contexts. Abiraterone acetate, by inhibiting androgen synthesis, deprives cancer cells androgens necessary for growth, while second-generation androgen receptor (AR) antagonists disrupt AR signaling by blocking AR binding, thereby impeding tumor progression. Given the predominance of prostate cancer in the elderly, who often present with multiple comorbidities requiring complex pharmacological regimens, the potential for drug-drug interactions with ARPIs is a critical concern. These interactions, particularly through pathways like CYP2D6 inhibition by abiraterone and CYP3A4 induction by enzalutamide and apalutamide, necessitate a thorough understanding to optimize therapeutic outcomes and minimize adverse effects. This review aims to delineate the efficacy of ARPIs in prostate cancer management and elucidate their interaction with common medications, highlighting the importance of vigilant drug management to optimize patient care.

Relugolix Plus Enzalutamide For Metastatic Hormone-Sensitive Prostate Cancer: A Case Report

Background

In the UK, relugolix, an oral gonadotropin-releasing hormone receptor antagonist, is indicated for advanced hormone-sensitive prostate cancer, and as neo-adjuvant and adjuvant treatment in combination with radiotherapy in patients with high-risk localised or locally advanced hormone-dependent prostate cancer. Experience with the combination of oral relugolix plus oral enzalutamide is limited.

Case Presentation

A white British male (66 years old) with a history of myelodysplastic syndrome, chronic neutropenia and indeterminate colitis presented with metastatic adenocarcinoma of the prostate gland. The patient started subcutaneous leuprorelin acetate and oral enzalutamide. After 8 weeks, the oral enzalutamide dose was reduced because of fatigue. Following the second leuprorelin injection, the patient developed a subcutaneous abscess that required surgical incision and drainage. The patient switched to oral relugolix and continued with oral enzalutamide. Within 3 months of commencing leuprorelin and enzalutamide the prostate specific antigen (PSA) concentration fell from a peak of 269.00 ng/mL to 2.55 ng/mL. Following the switch to oral relugolix plus enzalutamide, the PSA remained stable until the most recent assessment 11 months later. Relugolix plus enzalutamide was well tolerated.

Conclusion

Relugolix plus enzalutamide produced a sustained reduction in PSA and the combination was well tolerated. Further research including real world data should assess relugolix in doublet and triplet combinations for prostate cancer.

Pharmacokinetics and Safety of Atogepant Co-administered with Quinidine Gluconate in Healthy Participants: A Phase 1, Open-Label, Drug-Drug Interaction Study

Atogepant, an oral calcitonin gene-related peptide receptor antagonist, is approved for the preventive treatment of migraine. Atogepant is a substrate of P-glycoprotein (P-gp), breast cancer resistance protein, organic anion transporting polypeptide transporters, and cytochrome P450 (CYP)3A4 and 2D6. Quinidine is a strong P-gp and CYP2D6 inhibitor. A phase 1 open-label study evaluated the effect of P-gp and CYP2D6 inhibition by quinidine on the pharmacokinetics of atogepant, and the safety and tolerability of atogepant and quinidine gluconate (QG) when co-administered and when given alone in 33 healthy adults. There was no significant change in the atogepant maximum plasma concentration with QG co-administration. The overall systemic exposure, the area under the plasma concentration-time curve (from time 0 to time t or to infinity), of atogepant increased by 25% when co-administered with QG. However, such an increase was not considered clinically relevant. Atogepant did not alter the mean plasma concentration of quinidine at steady state. The incidence of treatment-emergent adverse events (TEAEs) was highest when QG was administered alone (42.4%), which was primarily due to QT prolongation. Most TEAEs reported were mild in severity and resolved within 1-2 days. Co-administration of atogepant with QG did not result in any unexpected tolerability findings in this phase 1 study in healthy participants. The increase in atogepant exposure during QG co-administration could be due to inhibition of CYP2D6 (a minor contributor to atogepant clearance) as well as inhibition of P-gp.

Pharmacokinetics-Pharmacodynamics Modeling for Evaluating Drug-Drug Interactions in Polypharmacy: Development and Challenges

Polypharmacy is commonly employed in clinical settings. The potential risks of drug-drug interactions (DDIs) can compromise efficacy and pose serious health hazards. Integrating pharmacokinetics (PK) and pharmacodynamics (PD) models into DDIs research provides a reliable method for evaluating and optimizing drug regimens. With advancements in our comprehension of both individual drug mechanisms and DDIs, conventional models have begun to evolve towards more detailed and precise directions, especially in terms of the simulation and analysis of physiological mechanisms. Selecting appropriate models is crucial for an accurate assessment of DDIs. This review details the theoretical frameworks and quantitative benchmarks of PK and PD modeling in DDI evaluation, highlighting the establishment of PK/PD modeling against a backdrop of complex DDIs and physiological conditions, and further showcases the potential of quantitative systems pharmacology (QSP) in this field. Furthermore, it explores the current advancements and challenges in DDI evaluation based on models, emphasizing the role of emerging in vitro detection systems, high-throughput screening technologies, and advanced computational resources in improving prediction accuracy.

Enzalutamide: Understanding and Managing Drug Interactions to Improve Patient Safety and Drug Efficacy

Enzalutamide is an oral androgen receptor signaling inhibitor utilized in the treatment of men with prostate cancer. It is a moderate inducer of the cytochrome P450 (CYP) enzymes CYP2C9 and CYP2C19, and a strong inducer of CYP3A4. It was also shown to be a mild inhibitor of the efflux transporter P-glycoprotein in patients with prostate cancer. Enzalutamide is primarily metabolized by CYP3A4 and CYP2C8. The risk of enzalutamide drug interactions arises primarily when it is coadministered with other drugs that interact with these CYPs, including CYP3A4. In this review, we begin by providing an overview of enzalutamide including its dosing, use in special populations, pharmacokinetics, changes to its prescribing information, and potential for interaction with coadministered drugs. Enzalutamide interactions with drugs from a wide range of medication classes commonly prescribed to patients with prostate cancer are described, including oral androgen deprivation therapy, agents used to treat a range of cardiovascular diseases, antidiabetic drugs, antidepressants, anti-seizure medications, common urology medications, analgesics, proton pump inhibitors, immunosuppressants, and antigout drugs. Enzalutamide interactions with common vitamins and supplements are also briefly discussed. This review provides a resource for healthcare practitioners and patients that will help provide a basis for the understanding and management of enzalutamide drug-drug interactions to inform decision making, improve patient safety, and optimize drug efficacy.

Physiologically based absorption modeling to predict the bioequivalence of two apixaban formulations

The equivalence of absorption rates and extents between generic drugs and their reference formulations is crucial for ensuring therapeutic comparability. Bioequivalence (BE) studies are widely utilized and play a pivotal role in substantiating the approval and promotional efforts for generic drugs. Virtual BE simulation is a valuable tool for mitigating risks and guiding clinical BE studies, thereby minimizing redundant in vivo BE assessments. Herein, we successfully developed a physiologically based absorption model for virtual BE simulations, which precisely predicts the BE of the apixaban test and reference formulations. The modeling results confirm that the test and reference formulations were bioequivalent under both fasted and fed conditions, consistent with clinical studies. This highlights the efficacy of physiologically based absorption modeling as a powerful tool for formulation screening and can be adopted as a methodological and risk assessment strategy to detect potential clinical BE risks.

Insight into the molecular interaction between the anticancer drug, enzalutamide and human alpha-2-macroglobulin: Biochemical and biophysical approach

The drug pharmacokinetics is affected upon binding with proteins, thus making drug-protein interactions crucial. This study investigated the interaction between enzalutamide and human major antiproteinase alpha-2-macroglobulin (α2M) by using multi spectroscopic and calorimetric techniques. The spectroscopic techniques such as circular dichroism (CD), intrinsic fluorescence, and UV-visible absorption were used to determine the mechanism of enzalutamide-α2M interaction. Studies on the quenching of fluorescence at three different temperatures showed that the enzalutamide-α2M complex is formed through static quenching mechanism. The change in microenvironment around tyrosine residues in protein was detected through synchronised fluorescence. The secondary structure of α2M was slightly altered by enzalutamide according to far UV-CD spectral analysis. Changes in position of amide I band in FTIR spectra further confirm the secondary structural alteration in α2M. According to thermodynamic characteristics such as fluorescence quenching and isothermal titration calorimetry (ITC), hydrogen bonds and hydrophobic interactions were involved in the interaction machanism. The ITC reiterated the exothermic and spontaneous nature of the interaction. The lower proteinase inhibitory activity of the α2M-enzalutamide conjugate as reflects the disruption of the native α2M structure upon interaction with enzalutamide.

Role of P-glycoprotein in Regulating the Efficacy, Toxicity and Pharmacokinetics of Yunaconitine

BACKGROUND

Yunaconitine (YAC) is a hidden toxin that greatly threatens the life safety of patients who are prescribed herbal medicines containing Aconitum species; however, its underlying mechanism remains unclear.

OBJECTIVE

The objective of this study is to elucidate the functions of P-glycoprotein (P-gp) in regulating the efficacy, toxicity, and pharmacokinetics of YAC.

METHODS

The efflux function of P-gp on YAC was explored by using Caco-2 monolayers in combination with the P-gp inhibitor verapamil. The impact of P-gp on regulating the analgesic and anti-inflammatory effects, acute toxicity, tissue distribution, and pharmacokinetics of YAC was determined via male Mdr1a gene knocked-out mice and wild-type FVB mice.

RESULTS

The presence of verapamil significantly decreased the efflux ratio of YAC from 20.41 to 1.07 in Caco- 2 monolayers (P < 0.05). Moreover, oral administration of 0.07 and 0.14 mg/kg YAC resulted in a notable decrease in writhing times in Mdr1a-/- mice by 23.53% and 49.27%, respectively, compared to wild-type FVB mice (P < 0.05). Additionally, the deficiency of P-gp remarkably decreased the half-lethal dose (LD50) of YAC from 2.13 to 0.24 mg/kg (P < 0.05). Moreover, the concentrations of YAC in the tissues of Mdr1a-/- mice were statistically higher than those in wild-type FVB mice (P < 0.05). Particularly, the brain accumulation of YAC in Mdr1a-/- mice significantly increased by 12- and 19-fold, respectively, after oral administration for 30 and 120 min, when compared to wild-type FVB mice (P < 0.05). There were no significant differences in the pharmacokinetic characteristics of YAC between Mdr1a-/- and wild-type FVB mice.

CONCLUSION

YAC is a sensitive substrate of P-gp. The absence of P-gp enhances the analgesic effect and toxicity of YAC by upregulating its brain accumulation. Co-administration with a P-gp inhibitor may lead to severe YAC poisoning.