Population pharmacokinetic and pharmacodynamic analysis of rivaroxaban in Chinese patients with non-valvular atrial fibrillation

Effect of ABCB1 SNP polymorphisms on the plasma concentrations and clinical outcomes of rivaroxaban in Chinese NVAF patients: a population pharmacokinetic-based study

Background

This study utilized a population pharmacokinetic (PPK) approach to assess the influence of ABCB1 genetic polymorphisms on the plasma concentrations and clinical outcomes of rivaroxaban.

Methods

The PPK model for rivaroxaban was developed using the nonlinear mixed-effects modelling approach and Monte Carlo simulations were employed to derive peak concentration (Cmax) and trough concentration (Ctrough). ABCB1 genetic variants were analyzed for their impact on the plasma concentrations and clinical outcomes.

Results

Analysis of 287 rivaroxaban plasma concentrations from 228 non-valvular atrial fibrillation (NVAF) patients revealed significant associations between AST (aspartate aminotransferase)/ALT (alanine aminotransferase) ratios and the apparent clearance (CL/F), the apparent volume of distribution (V/F). ABCB1 1236C>T TT and ABCB1 c.2482-2236C>T CC genotypes exhibited higher dose-adjusted Cmax (Cmax/D) compared to other relevant genotypes. Additionally, the ABCB1 3435C>T TT genotype showed lower dose-adjusted Ctrough (Ctrough/D) compared to CC or CT genotypes. For clinical outcomes, the ABCB1 c.2482-2236C>T CC genotype had a higher bleeding risk compared to TT (RR = 1.99, 95% CI 1.08-3.69) or CT genotypes (RR = 1.42, 95% CI 1.04-1.92), and ABCB1 3435C>T TT genotype showed a higher thromboembolic risk compared to CC genotype (RR = 3.48, 95% CI 1.02-11.85).

Conclusion

The PPK model incorporated CL/F and V/F with the covariate AST/ALT. Model-based simulations revealed that ABCB1 1236C>T, ABCB1 c.2482-2236C>T, and ABCB1 3435C>T genotypes had significant impacts on the plasma concentrations of rivaroxaban. Specifically, ABCB1 c.2482-2236C>T and ABCB1 3435C>T genotypes were associated with bleeding events and thromboembolic events, respectively.

Population pharmacokinetics of levetiracetam in Chinese adult epilepsy patients with varying renal function: exposure simulation and individualized dosing adjustments

Levetiracetam (LEV) has become a first-line treatment option for various types of epilepsy with a broad spectrum of efficacy and favorable pharmacokinetic profile. We aimed to develop a population pharmacokinetic (PPK) model for LEV and devise a model-based dosing guideline specific to Chinese adult epilepsy patients. Employing Phoenix NLME 7.0 software, we utilized the first-order conditional estimation and extended least squares method to establish the PPK model. The PK of LEV was effectively characterized using a one-compartment model. Monte Carlo simulations were then performed to generate dosing guidelines suitable for various patient groups. The Bayesian feedback method was employed to develop the clinical individual predictive model. Data from 80 Chinese adult patients yielded 148 LEV plasma concentrations for analysis. In the final model, the absorption rate constant was fixed at 2.44. The apparent volume of distribution and the apparent clearance (CL/F) had population typical values of 35.34 L and 3.24 L/h, respectively. CL/F of LEV was significantly influenced by creatinine clearance (CrCL), identified as a major covariate. Monte Carlo simulations indicated that regimens of 0.5 g, 0.75 g, 1.0 g, 1.5 g, 2.0 g, 2.5 g, and 3.5 g twice daily were associated with the highest probability of target attainment (PTA) in patients with different renal function levels. Accordingly, a user-friendly dose recommendation was formulated for these patients. The individual predictive model accurately matched the observed concentrations and managed to guide the personalized dose adjustment. The PPK model linked CL/F to CrCL. Model-based simulations suggest that higher dosage adjustments may be necessary for those with augmented renal function. The developed clinical individual predictive model could effectively guide personalized dose adjustments, potentially reducing the need for frequent drug concentration measurements.

Establishment of an Integrated Population Pharmacokinetic/ Pharmacodynamics Model of Apixaban in Chinese Healthy Population Adjusting for Key Genetic Variants

AIMS

To improve the understanding of pharmacokinetic/pharmacodynamic (PK/PD) profiles of apixaban, supporting personalised drug prescriptions for future patients.

BACKGROUND

Genetic as well as nongenetic factors can affect the predictable PK and PD characteristics of apixaban.

OBJECTIVE

Establish a integrated popPK/PD model that adjusts for critical genetic variant.

METHODS

The integrated PK/PD models was characterized on the basis of PK (apixaban blood concentration) and PD (prothrombin time (PT), activated partial thromboplastin time (APTT), and anti-FXa activity) data from 181 healthy Chinese volunteers. Other investigated covariate variables included: Meaningful intrinsic and extraneous determinants, correlated genetic factors (ABCG2, F13A1, C3, etc.). A total of 2877 PK concentration observations were included in the modeling dataset.

RESULTS

The PK model of apixaban is adopted by single compartment model with first-order oral absorption. The estimated values of total clearance rate (CL/F), apparent distribution volume (V/F), and absorption rate constant (KA) in the final model are 3.37 L/h, 28.2 L, and 0.781 1/h, respectively. The PK model includes significance covariates such as FOOD, RBC, WT, and gene (ABCG2). The PD model of apixaban is adopted by a linear direct effect model with additive error, which was used to describe the relationship between markers such as APTT, PT, anti-FXa, versus plasma concentration. PK simulation within the modelled dose range is similar to clinical real date, while PD simulation results also show that the simulated exposure parameters is within the range of the literature.

CONCLUSION

We established a comprehensive PK/PD model and used it to simulate markers level such as APTT, PT, and anti-FXa of apixaban. Individual predictive values with a dose of 2.5 mg are basically within the expected recommended range.

Population pharmacokinetics of rivaroxaban in Chinese deep vein thrombosis patients and the exposure simulation for dosing recommendation

This study aimed to develop a population pharmacokinetic (PPK) model for rivaroxaban and establish a model-based dosing guideline tailored to Chinese patients with deep vein thrombosis (DVT). A nonlinear mixed-effects modeling approach was employed using Phoenix NLME 7.0 software to construct the PPK model for rivaroxaban. The PK of rivaroxaban was adequately characterized through a one-compartment model. Monte Carlo simulations were employed to formulate dosing guidelines applicable to different patient subgroups. Data from 60 Chinese DVT patients yielded 217 rivaroxaban plasma concentrations for analysis. The apparent clearance (CL/F) of rivaroxaban was found to be significantly influenced by the estimated glomerular filtration rate (eGFR), identified as a major covariate. Based on Monte Carlo simulations, for the acute DVT treatment, a regimen of 15 mg, 10 mg, or 5 mg twice daily was associated with the highest total probability target attainment (PTAtotal) in patients with normal, mildly impaired, or moderately impaired renal function, respectively. For the continued DVT treatment, a regimen of 20 mg, 15 mg, or 5 mg once daily exhibited the maximum PTAtotal in patients with normal, mildly impaired, or moderately impaired renal function, respectively. The recommendation label dose achieved the PK target in those with normal renal function. However, for patients with mild or moderate renal impairment, dose adjustments below the label recommendation might be necessary. The PPK model associated CL/F with the covariate eGFR. Utilizing the PPK model, a dosage regimen table was constructed to offer tailored dosing recommendations for Chinese DVT patients.

Effectiveness and safety of rivaroxaban for anticoagulation therapy in COVID-19: A meta-analysis of randomized controlled trials

OBJECTIVES

To evaluate the effectiveness and safety of rivaroxaban anticoagulation in COVID-19 patients.

METHODS

PubMed, Embase, Cochrane Library electronic databases, and ClinicalTrials.gov were searched to identify all relevant randomized controlled trial studies from December 2019 to July 2023.

RESULTS

A total of 6 randomized controlled trials, which included a total of 3323 patients, were considered for evaluation. Overall, short-term all-cause mortality and hospitalization rates were not significantly different between the rivaroxaban and control groups. Thrombotic events were significantly reduced in the rivaroxaban prophylaxis group compared to the placebo control group. However, the reduction in thrombotic events was not significantly different between rivaroxaban therapy and heparin or low-molecular-weight heparin (LMWH). Rivaroxaban prophylaxis and the therapeutic dose may be associated with a higher rate of overall bleeding rate, but major bleeding rates did not differ substantially.

CONCLUSION

Rivaroxaban may reduce thrombotic events in COVID-19 patients, but it does not appear to have an advantage over heparin or LMWH, and it may increase the risk of bleeding.INPLASY Reg. No.: INPLASY 202370097.

Insights into the Pharmacokinetics and Pharmacodynamics of Direct Oral Anticoagulants in Older Adults with Atrial Fibrillation: A Structured Narrative Review

Older adults, the fastest growing population, represent almost 50% of all users of direct oral anticoagulants (DOACs). Unfortunately, we have very little relevant pharmacological and clinical data on DOACs, especially in older adults with geriatric profiles. This is highly relevant as pharmacokinetics and pharmacodynamics (PK/PD) often differ substantially in this population. Hence, we need to obtain a better understanding of the PK/PD of DOACs in older adults, to ensure appropriate treatment. This review summarises the current insights into PK/PD of DOACs in older adults. A search was undertaken up to October 2022 to identify PK/PD studies of apixaban, dabigatran, edoxaban, and rivaroxaban, that included older adults aged ≥ 75 years. This review identified 44 articles. Older age alone did not influence exposure of edoxaban, rivaroxaban and dabigatran, while apixaban peak concentrations were 40% higher in older adults than in young volunteers. Nevertheless, high interindividual variability in DOAC exposure in older adults was noted, which can be explained by distinctive older patient characteristics, such as kidney function, changes in body composition (especially reduced muscle mass), and co-medication with P-gp inhibitors, which is in line with the current dosing reduction criteria of apixaban, edoxaban, and rivaroxaban. Dabigatran had the largest interindividual variability among all DOACs since its dose adjustment criterion is only age, and thus it is not a preferable option. Additionally, DOAC exposure, which fell outside of on-therapy ranges, was significantly related to stroke and bleeding events. No definite thresholds linked to these outcomes in older adults have been established.

Transferability of Published Population Pharmacokinetic Models for Apixaban and Rivaroxaban to Subjects with Obesity Treated for Venous Thromboembolism: A Systematic Review and External Evaluations

Apixaban and rivaroxaban have first-line use for many patients needing anticoagulation for venous thromboembolism (VTE). The pharmacokinetics of these drugs in non-obese subjects have been extensively studied, and, while changes in pharmacokinetics have been documented in obese patients, data remain scarce for these anticoagulants. The aim of this study was to perform an external validation of published population pharmacokinetic (PPK) models of apixaban and rivaroxaban in a cohort of obese patients with VTE. A literature search was conducted in the PubMed/MEDLINE, Scopus, and Embase databases following the PRISMA statement. External validation was performed using MonolixSuite software, using prediction-based and simulation-based diagnostics. An external validation dataset from the university hospitals of Brest and Rennes, France, included 116 apixaban pharmacokinetic samples from 69 patients and 121 rivaroxaban samples from 81 patients. Five PPK models of apixaban and 16 models of rivaroxaban were included, according to the inclusion criteria of the study. Two of the apixaban PPK models presented acceptable performances, whereas no rivaroxaban PPK model did. This study identified two published models of apixaban applicable to apixaban in obese patients with VTE. However, none of the rivaroxaban models evaluated were applicable. Dedicated studies appear necessary to elucidate rivaroxaban pharmacokinetics in this population.

Is a Lower Dose of Rivaroxaban Required for Asians? A Systematic Review of a Population Pharmacokinetics and Pharmacodynamics Analysis of Rivaroxaban

Rivaroxaban has been widely used to prevent and treat various thromboembolic diseases for more than a decade. However, whether a lower dose of rivaroxaban is required for Asians is still debatable. This review aimed to explore the potential ethnic difference in pharmacokinetic/pharmacodynamic (PK/PD) characteristics between Asians and Caucasians. A systematic search was conducted and twenty-four studies were identified, of which 10 were conducted on Asian adults, 11 on predominantly Caucasian adults, and 3 on Caucasian pediatrics. The apparent clearance (CL/F) of rivaroxaban in Caucasian adults with non-valvular atrial fibrillation (6.45-7.64 L/h) was about 31-43% higher than that in Asians (4.46-5.98 L/h) taking 10~20 mg rivaroxaban every 24 h. Moreover, there was no obvious difference in CL/F among Japanese, Chinese, Thai, and Irani people. Regarding PK/PD relationship, prothrombin time was linked to rivaroxaban concentration in a linear or near-linear manner, and Factor Xa activity was linked with the E_max model. The exposure-response relationship was comparable between Asians and Caucasians. Renal function has a significant influence on CL/F, and no covariate was recognized for exposure-response relationship. In conclusion, a lower dose of rivaroxaban might be required for Asians, and further studies are warranted to verify this ethnic difference to facilitate optimal dosing regimens.

Population Pharmacokinetics and Dose Optimization Based on Renal Function of Rivaroxaban in Thai Patients with Non-Valvular Atrial Fibrillation

Low-dose rivaroxaban has been used in Asian patients with direct oral anticoagulants (DOACs) eligible for atrial fibrillation (AF). However, there are few pharmacokinetic (PK) data in Thai patients to support precise dosing. This study aimed to develop a population PK model and determine the optimal rivaroxaban doses in Thai patients. A total of 240 Anti-Xa levels of rivaroxaban from 60 Thai patients were analyzed. A population PK model was established using the nonlinear mixed-effect modeling approach. Monte Carlo simulations were used to predict drug exposures at a steady state for various dosages. Proportions of patients having rivaroxaban exposure within typical exposure ranges were determined. A one-compartment model with first-order absorption best described the data. Creatinine clearance (CrCl) and body weight significantly affected CL/F and V/F, respectively. Regardless of body weight, a higher proportion of patients with CrCl < 50 mL/min receiving the 10-mg once-daily dose had rivaroxaban exposures within the typical exposure ranges. In contrast, a higher proportion of patients with CrCl ≥ 50 mL/min receiving the 15-mg once-daily dose had rivaroxaban exposures within the typical exposure ranges. The study’s findings suggested that low-dose rivaroxaban would be better suited for Thai patients and suggested adjusting the medication’s dose in accordance with renal function.