Direct Oral Anticoagulants for the Treatment of Venous Thromboembolism in Japan

Hypersensitivity reaction to rivaroxaban with a successful switch to apixaban: A case report

Key Clinical Message

The precise management of hypersensitivity reactions to direct oral anticoagulants (DOACs) and the potential for cross-reactivity among different DOACs remain unclear. In such cases, switching between DOACs may be feasible and could be considered, but close monitoring for adverse effects is essential, tailored to individual patient responses and tolerability.

Abstract

Hypersensitivity reactions to DOACs, though considered rare, have been documented. This report describes the case of a 28-year-old male with a history of testicular cancer who was recently diagnosed with deep vein thrombosis. He was referred to an outpatient pharmacotherapy clinic due to suspected rivaroxaban-induced cutaneous reactions. Following a thorough evaluation, his anticoagulant therapy was switched from rivaroxaban to apixaban. This change was successfully implemented, and no hypersensitivity symptoms recurred during subsequent follow-up. This case demonstrates the importance of recognizing potential adverse reactions to DOACs and illustrates the feasibility of switching anticoagulants under close medical supervision to ensure patient safety and effective treatment.

Challenges and Possible Solutions to Direct-Acting Oral Anticoagulants (DOACs) Dosing in Patients with Extreme Bodyweight and Renal Impairment

This article aims to highlight the dosing issues of direct oral anticoagulants (DOACs) in patients with renal impairment and/or obesity in an attempt to develop solutions employing advanced data-driven techniques. DOACs have become widely accepted by clinicians worldwide because of their superior clinical profiles, more predictable pharmacokinetics, and hence more convenient dosing relative to other anticoagulants. However, the optimal dosing of DOACs in extreme bodyweight  patients and patients with renal impairment is difficult to achieve using the conventional dosing approach. The standard dosing approach (fixed-dose) is based on limited data from clinical studies. The existing formulae (models) for determining the appropriate doses for these patient groups leads to suboptimal dosing. This problem of mis-dosing is worsened by the lack of standardized laboratory parameters for monitoring the exposure to DOACs in renal failure and extreme bodyweight patients. Model-informed precision dosing (MIPD) encompasses a range of techniques like machine learning and pharmacometrics modelling, which could uncover key variables and relationships as well as shed more light on the pharmacokinetics and pharmacodynamics of DOACs in patients with extreme bodyweight or renal impairment. Ultimately, this individualized approach-if implemented in clinical practice-could optimise dosing for the DOACs for better safety and efficacy.

Comparative effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with venous thromboembolism: A cohort study

BACKGROUND

Although several studies have compared the effectiveness and safety of rivaroxaban and apixaban in patients with venous thromboembolism (VTE), direct comparison of these drugs with edoxaban is lacking.

OBJECTIVE

We compared the effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with VTE.

PATIENTS/METHODS

In this retrospective cohort study using a Japanese hospital administrative database, we identified three mutually exclusive groups of patients with VTE beginning treatment with edoxaban, rivaroxaban, or apixaban. Primary effectiveness outcome was recurrent VTE, and principal safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding. Subjects were followed for up to 180 days. Baseline characteristics among groups were balanced using propensity score matching weights.

RESULTS

Three thousand three hundred sixty-nine edoxaban, 1592 rivaroxaban, and 1998 apixaban initiators were identified. There were no significant differences among the three drugs in the prevention of recurrent VTE (adjusted incidence rate ratio [aIRR], 0.77; 95% confidence interval [CI], 0.45-1.30 for edoxaban vs. rivaroxaban; aIRR, 0.92; 95% CI, 0.54-1.56 for edoxaban vs. apixaban; and aIRR, 1.20; 95% CI, 0.69-2.10 for rivaroxaban vs. apixaban), or in the risk of intracranial hemorrhage or gastrointestinal bleeding (aIRR, 1.57, 95% CI, 0.85-2.90 for edoxaban vs. rivaroxaban; aIRR, 1.30, 95% CI, 0.76-2.23 for edoxaban vs. apixaban; and aIRR, 0.83, 95% CI, 0.42-1.64 for rivaroxaban vs. apixaban).

CONCLUSIONS

In routine care, edoxaban, rivaroxaban, and apixaban appear to have similar effectiveness and safety in the treatment of VTE.

Safety and Effectiveness of Apixaban in Japanese Patients With Venous Thromboembolism in Clinical Practice - A Post-Marketing Surveillance

BACKGROUND

A post-marketing surveillance study (STANDARD-VTE) evaluated the real-world safety and effectiveness of apixaban in Japanese patients prescribed for either the treatment of venous thromboembolism (VTE) or prevention of recurrent VTE.

METHODS AND RESULTS

Patients newly initiated on apixaban were followed up for 52 weeks or 28 days post-discontinuation. Subgroup analysis was performed on patients with and without active cancer, and on patients with provoked VTE and with unprovoked VTE. A total of 1,119 patients were enrolled. Of these, 43.1% were aged ≥75 years, 46.4% had body weight ≤60 kg, and 21.3% had active cancer; mean serum creatinine was 0.76 mg/dL. The incidence of adverse drug reactions (ADRs) was 8.85%, and that of severe ADRs was 3.22%. Incidence of any bleeding, major bleeding, and recurrent VTE was 6.70%, 3.40%, and 0.80%, respectively. In patients starting apixaban 10 mg twice daily, THE incidence of any bleeding and major bleeding was 7.72% and 3.86%, respectively. In patients with active cancer, THE incidence of any bleeding and major bleeding was 16.81% and 9.24%, respectively.

CONCLUSIONS

No new safety signals of apixaban were identified in Japanese patients with VTE. In this study, the safety and effectiveness of apixaban in real-world practice was consistent with the results of the apixaban phase III trial.

Rivaroxaban Suppresses the Progression of Ischemic Cardiomyopathy in a Murine Model of Diet-Induced Myocardial Infarction

AIM

A direct oral anti-coagulant, FXa inhibitor, has been applied to the clinical treatment of myocardial infarction (MI). Experimental studies in mice indicated that FXa inhibitors reduced atherosclerosis and prevented cardiac dysfunction after coronary ligation. These studies suggested that protease-activated receptor (PAR) 2, a major receptor of activated FX, may play an important role in atherosclerosis and cardiac remodeling.

METHODS

The effects of a FXa inhibitor, rivaroxaban, were investigated in a new murine model of ischemic cardiomyopathy (ICM) using SR-BI KO/ApoeR61h/h mice (Hypo E mice) that developed MI by high-fat diet loading.

RESULTS

Hypo E mice were fed rivaroxaban-containing (n=49) or control chow diets (n=126) after the induction of MI. The survival curve of the rivaroxaban-treated group 2 weeks after the induction of MI was improved significantly as compared with the non-treatment group (survival rate: 75.5% vs. 47.4%, respectively, p=0.0012). Echocardiography and the expression of BNP showed that rivaroxaban attenuated heart failure. Histological analyses revealed that rivaroxaban reduced aortic atherosclerosis and coronary occlusion, and markedly attenuated cardiac fibrosis. Rivaroxaban treatment decreased cardiac PAR2 levels and pro-inflammatory genes. In vitro, rivaroxaban application demonstrated the increase of cell viability against hypoxia in cardiac myocytes and the reduction of hypoxia-induced inflammation and fibrosis-related molecules in cardiac fibroblasts. The effects of the PAR2 antagonist against hypoxia-induced inflammation were comparable to rivaroxaban in cardiac fibroblasts.

CONCLUSIONS

Rivaroxaban treatment just after MI in Hypo E mice prevented the progression of ICM by attenuating cardiac remodeling, partially through the suppression of the PAR2-mediated inflammatory pathway.

Pulmonary Embolism: Contemporary Medical Management and Future Perspectives

Pulmonary embolism (PE) contributes substantially to the global disease burden. A key determinant of early adverse outcomes is the presence (and severity) of right ventricular dysfunction. Consequently, risk-adapted management strategies continue to evolve, tailoring acute treatment to the patients' clinical presentation, hemodynamic status, imaging and biochemical markers, and comorbidity. For subjects with hemodynamic instability or 'high-risk' PE, immediate systemic reperfusion treatment with intravenous thrombolysis is indicated; emerging approaches such as catheter-directed pharmacomechanical reperfusion might help to minimize the bleeding risk. Currently, direct, non-vitamin K-dependent oral anticoagulants are the mainstay of treatment for acute PE. They have been shown to simplify initial and extended anticoagulation regimens while reducing the bleeding risk compared to vitamin K antagonists. (This is a review article based on the invited lecture of the 37th Annual Meeting of Japanese Society of Phlebology.).

Pharmacokinetics of anticoagulants apixaban, dabigatran, edoxaban and rivaroxaban in elderly Japanese patients with atrial fibrillation treated in one general hospital

Steady-state plasma concentrations of anticoagulants and the time since the previous administration in mainly outpatients with atrial fibrillation administered standard or reduced doses were analyzed for 110 elderly Japanese subjects (mean age, 76 years) treated with apixaban (2.5 or 5.0 mg twice daily), dabigatran etexilate (110 or 150 mg twice daily), edoxaban (30 or 60 mg once daily) or rivaroxaban (10 or 15 mg once daily) at one general hospital. The pharmacokinetics in patients treated with standard and reduced doses of the four anticoagulants using liquid chromatography-tandem mass spectrometry was compared with the concentration ranges estimated using physiologically based pharmacokinetic modeling. Reduced doses of anticoagulants resulted in relatively small pharmacokinetic variations compared with the standard dose. Statistical analyses revealed that renal impairment is likely not the sole determinant factor for high plasma concentrations of apixaban, dabigatran, edoxaban and rivaroxaban. Patients with atrial fibrillation should be treated with the correct doses of oral anticoagulants as specified in the package inserts (e.g. reduced doses for elderly patients, patients with low body weights and in combination with P-glycoprotein inhibitor drugs) to avoid excessive or insufficient doses of direct oral anticoagulants.