Mutant CYP3A4/5 Correlated with Clinical Outcomes by Affecting Rivaroxaban Pharmacokinetics and Pharmacodynamics in Patients with Atrial Fibrillation

Application of a Novel UPLC-MS/MS Method for Analysis of Rivaroxaban Concentrations in Dried Blood Spot and Plasma Samples Collected from Patients with Venous Thrombosis

Despite a higher safety profile compared to vitamin K antagonists, rivaroxaban therapy is still connected with multiple adverse effects, such as a high risk of bleeding. Thus, therapeutic drug monitoring (TDM) of rivaroxaban concentrations is suggested. An alternative to plasma samples can be dried blood spots (DBS), which minimize the cost of sample storage and transport. In this study, we developed a UPLC-MS/MS method for the analysis of rivaroxaban in DBS and plasma samples. Chromatographic separation was achieved on a Zorbax Eclipse Plus C18 column (2.1 × 100 mm; 3.5 µm, Agilent Technologies Inc., Santa Clara, CA, USA) with a mobile phase consisting of water and acetonitrile, both containing 0.1% formic acid. The analytes were detected using a positive ionization mode by multiple reaction monitoring. We validated the method according to ICH guidelines. The precision and accuracy were satisfactory. Extraction recovery was approximately 57% and 66% for DBS and plasma samples, respectively. A high correlation between rivaroxaban concentrations in plasma and DBS samples collected from patients was confirmed with Deming regression. The suitability of both sampling techniques for the rivaroxaban TDM was also verified by Bland-Altman plots based on DBS-predicted and observed plasma concentrations. In addition, we found a significant relationship between rivaroxaban concentrations and coagulation parameters, including prothrombin time (PT) and international normalized ratio (INR).

Direct oral anticoagulants in trauma patients

PURPOSE OF REVIEW

Direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. Thus, trauma care providers are facing a steadily raising number of injured patients on DOACs.

RECENT FINDINGS

Despite a predictable pharmacokinetic profile, the resulting plasma levels of trauma patients upon admission and bleeding risks remain uncertain. Therefore, recent guidelines recommend the measurement of DOAC plasma concentrations in injured patients. Alternatively, DOAC specific visco-elastic tests assays can be applied to identify DOAC patients at bleeding risk.Bleeding complications in trauma patients on DOACs are generally higher compared to nonanticoagulated subjects, but comparable to vitamin K antagonists (VKAs). In particular, a traumatic brain injury does not carry an increased risk of intracranial bleeding due to a DOAK intake compared to VKAs. Current studies demonstrated that up to 14% of patients with a hip fracture are on DOACs prior to surgery. However, the majority can be operated safely within a 24h time window without an increased bleeding rate.Specific antagonists facilitate rapid reversal of patients on DOACs. Idarucizumab for dabigatran, and andexanet alfa for apixaban and rivaroxaban have been approved for life threatening bleeding. Alternatively, prothrombin complex concentrate can be used. Dialysis is a potential treatment option for dabigatran and haemoabsorption with special filters can be applied in patients on FXa-inhibitors.

SUMMARY

Current guidelines recommend the measurement of DOAC plasma levels in trauma patients. Compared to VKAs, DOACs do not carry a higher bleeding risk. DOAC specific antagonists facilitate the individual bleeding management.

Rivaroxaban Plasma Concentration and Clinical Outcomes on Older Patients with Non-valvular Atrial Fibrillation and Pulmonary Infection

INTRODUCTION

Infection may induce thrombotic and hemorrhagic events; however, it is currently unclear whether the inflammatory response affects the coagulation function and the clinical efficacy and safety of rivaroxaban in older patients with non-valvular atrial fibrillation (NVAF).

OBJECTIVE

This project aimed to assess the effectiveness and safety of the non-vitamin K antagonist oral anticoagulant rivaroxaban in older patients with NVAF complicated by infection, and to provide a basis for possible drug dose adjustment.

METHODS

A total of 152 NVAF patients aged ≥ 65 years admitted to the Fifth People's Hospital of Shanghai from June 2020 to May 2022 were included in this prospective, observational study. The changes in steady-state plasma concentration of rivaroxaban and FXa inhibition rate were compared between patients with and without infection, and the impact on the occurrence of infection, thrombotic events, and bleeding events was compared through 1-year follow-up.

RESULTS

Our results showed that patients in the infection group had abnormal inflammation markers, as well as an increased occurrence of bleeding and thrombotic events during hospitalization and follow-up. The high incidence of bleeding events in patients was closely related to the occurrence of infection, lymphocyte reduction, and increased neutrophil-lymphocyte ratio. The increase in thrombotic events was related to a decrease in rivaroxaban plasma concentration. Bleeding events in patients taking anticoagulant drugs are not necessarily due to drug accumulation.

CONCLUSIONS

Timely control of infection, assessment of bleeding and thrombotic risks, and selection of appropriate anticoagulation treatment strategies should be made in older NVAF patients who develop pulmonary infection.

CLINICAL TRIALS REGISTRATION

Chinese Clinical Trial Registry Number ChiCTR2000033144.