Apixaban: a review of its use in the prevention of venous thromboembolism after knee or hip replacement surgery

Effectiveness and Safety of Apixaban vs Warfarin in Patients with Venous Thromboembolism with Risk Factors for Bleeding or for Recurrences

INTRODUCTION

Patients at increased risk of bleeding and recurrent VTE who develop venous thromboembolism (VTE) present challenges for clinical management. This study evaluated the effectiveness and safety of apixaban vs warfarin in patients with VTE who have risk factors for bleeding or recurrences.

METHODS

Adult patients with VTE initiating apixaban or warfarin were identified from five claims databases. Stabilized inverse probability treatment weighting (IPTW) was used to balance characteristics between cohorts for the main analysis. Subgroup interaction analyses were conducted to evaluate treatment effects among patients with and without each of the conditions that increased the risk of bleeding (thrombocytopenia and history of bleed) or recurrent VTE (thrombophilia, chronic liver disease, and immune-mediated disorders).

RESULTS

A total of 94,333 warfarin and 60,786 apixaban patients with VTE met selection criteria. After IPTW, all patient characteristics were balanced between cohorts. Apixaban (vs warfarin) patients were at lower risk of recurrent VTE (HR [95% confidence interval (CI) 0.72 [0.67-0.78]), major bleeding (MB) (HR [95% CI] 0.70 [0.64-0.76]), and clinically relevant non-major (CRNM) bleeding (HR [95% CI] 0.83 [0.80-0.86]). Subgroup analyses showed generally consistent findings with the overall analysis. For most subgroup analyses, there were no significant interactions between treatment and subgroup strata on VTE, MB and CRNM bleeding.

CONCLUSION

Patients with prescription fills for apixaban had lower risk of recurrent VTE, MB, and CRNM bleeding compared with warfarin patients. Treatment effects of apixaban vs warfarin were generally consistent across subgroups of patients at increased risk of bleeding/recurrences.

LC-MS/MS Method Assay for Simultaneous Determination of the Apixaban and Metformin in Rat Plasma: Assessment of Pharmacokinetic Drug-Drug Interaction Study

A simple, sensitive and accurate LC-MS/MS method was developed and validated for the simultaneous quantification of apixaban (APB) and metformin (MET) in rat plasma using rivaroxaban as internal standard (IS). An Inertsil ODS3 C18 column (150 × 4.6 mm, 5 μm) was used for chromatographic separation with isocratic elution. Multiple reaction monitoring (MRM) using positive-ion ESI mode to monitor ion transitions of m/z 459.8 → 442.8 for APB, m/z 130.2 → 71.2 for MET, m/z 436.8 → 144.9 for IS. The procedure of method validation included selectivity, linearity, precision, accuracy, matrix effect, extraction recovery and stability were conducted according to the guidelines of EMA and FDA. The method was validated over the concentration range of 0.5-250 ng/mL for APB and 8-8000 ng/mL for MET. The intra- and inter-day precision and accuracy of the quality control samples exhibited relative standard deviations (RSD) < 12.5% and the accuracy values ranged from -8.6 to 12.4%. Recovery and matrix effect values variations were all less than 15%. After oral administration APB and MET to rats, the comparison of pharmacokinetic parameters of APB in the single and co-administrated groups showed significant difference in AUC(0-t) from 730.71 ± 121.31 to 573.07 ± 90.13 ng/mL·h, t1/2 from 5.86 ± 3.21 to 4.24 ± 1.15 h and Cmax from113.54 ± 24.04 to 159.42 ± 54.6 ng/mL. The comparison of pharmacokinetic parameters of MET in the single and co-administrated groups showed significant difference in t1/2 from 2.83 ± 1.81 to 3.97 ± 0.57 h and Cmax from 4015.76 ± 873.23 to 3153.6 ± 1012.51 ng/mL. The results indicated that drug-drug interactions (DDI) occurred might be owing to APB affect one or all of OCTs, MATE1, MATE2-K.

Apixaban or enoxaparin: Which is better for thromboprophylaxis after total hip and total knee arthroplasty in Indian patients?

Both apixaban and enoxaparin are Food and Drug Administration-approved standard therapy for prophylaxis of deep-vein thrombosis; however, the superiority of one over the other is still controversial. With an objective to observe efficacy and safety outcomes of apixaban and enoxaparin in patients undergoing total hip (THA) and knee (TKA) arthroplasty, 96 patients undergoing THA/TKA (October 2018 to August 2019) were randomly allocated into 2 groups; (n = 48) apixaban; and (n = 48) enoxaparin. Efficacy outcomes and safety outcomes were recorded at 2 and 5 weeks post-TKA/THA. Follow-up functional scoring was done at 6 months postoperatively. Apixaban and enoxaparin were found to be equally efficacious in preventing venous thromboembolism; however, apixaban had a better safety profile. The apixaban group had nonsignificant higher tendency for wound discharge, atrial fibrillation and transient ischaemic attack. Enoxaparin had nonsignificant greater tendency for bleeding, wound dehiscence and pulmonary complications. Apixaban is a safe alternative to conventionally used enoxaparin for chemoprophylaxis in patients undergoing THA or TKA.

Apixaban: A Review in Venous Thromboembolism

Apixaban (Eliquis^®) is an oral, direct factor Xa inhibitor that is available for use in the treatment and secondary prevention of venous thromboembolism (VTE). Like other direct oral anticoagulants (DOACs), apixaban has generally predictable pharmacological properties and does not require routine anticoagulation monitoring. In large phase III trials, oral apixaban was noninferior to subcutaneous enoxaparin sodium overlapped with and followed by oral warfarin (enoxaparin/warfarin) in the treatment of adults with acute VTE over 6 months with regard to the incidence of recurrent VTE or VTE-related death (AMPLIFY), and was significantly more effective than placebo in the prevention of recurrent VTE or all-cause mortality over 12 months in patients who had completed 6-12 months' anticoagulation treatment for VTE (AMPLIFY-EXT). Apixaban was generally well tolerated in these trials; the risks of major bleeding and the composite endpoint of major or clinically relevant nonmajor (CRNM) bleeding with apixaban were significantly lower than enoxaparin/warfarin in AMPLIFY and not significantly different from that of placebo in AMPLIFY-EXT. Similarly, in Japanese adults with acute VTE (AMPLIFY-J), apixaban was associated with a significantly lower risk of major or CRNM bleeding than unfractionated heparin plus warfarin, and no cases of recurrent VTE or VTE-related death over 24 weeks. Thus, apixaban is useful therapeutic alternative for the management of adults with VTE.

Spontaneous splenic rupture associated with apixaban: a case report

BACKGROUND

Spontaneous splenic rupture associated with anticoagulant use is a rare but potentially lethal disorder. Lack of prompt recognition can be associated with poor patient outcomes. The use of novel oral anticoagulants is becoming more common and thus consideration of this disorder while evaluating a patient who presents with abdominal pain while using these agents is extremely important. This is the first reported case of spontaneous splenic rupture associated with apixaban.

CASE PRESENTATION

We describe the clinical case of an 83-year-old white man who complained of sudden severe abdominal pain 5 days into a hospital stay for acute-on-chronic congestive heart failure and exacerbation of chronic obstructive pulmonary disease. Neither he nor his wife reported any significant trauma for the past 6 months prior to his admission. His medical history included chronic atrial fibrillation treated with medications including apixaban 2.5 mg twice daily. An urgent abdominal computed tomography scan demonstrated a large splenic hematoma and evidence of intraperitoneal bleeding from which he rapidly declined, developing hypovolemic shock. An emergency splenic arteriogram displayed a patent splenic artery and an embolization was successful in stabilizing him. Due to evidence of recurrent bleeding, an exploratory laparotomy and splenectomy was subsequently performed the following day.

CONCLUSIONS

The diagnosis of spontaneous splenic rupture is important to consider in a patient using apixaban who presents with abdominal pain and associated signs of hypotension and anemia. For hemodynamically unstable patients, prompt treatment to stop significant bleeding through splenic artery embolization or splenectomy is warranted and may be lifesaving.

Determination of potential main sites of apixaban binding in human serum albumin by combined spectroscopic and docking investigations

Probing apixaban binding to human serum albumin: combining spectroscopic methods and docking investigations.

Clinical utility of apixaban in the prevention and treatment of venous thromboembolism: current evidence

Anticoagulation with heparin and vitamin K antagonist has been the mainstay of prevention and treatment of venous thromboembolism (VTE) for many years. In recent years, novel oral anticoagulants such as dabigatran etexilate (a direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (a direct factor Xa inhibitor) have emerged for the prevention and treatment of VTE. Novel oral anticoagulants have been shown to be noninferior to vitamin K antagonist or heparin in the prevention and treatment of VTE. This review specifically examines the role of apixaban in the prevention and treatment of VTE based on the available literature. The management of apixaban in the perioperative setting is also explored because some patients on apixaban may require surgical intervention. Finally, we discuss the management of apixaban-induced major bleeding complications, the relevance of drug–drug interactions, and patient education.

Selective tissue factor/factor VIIa Inhibitor, ER-410660, and its prodrug, E5539, have anti-venous and anti-arterial thrombotic effects with a low risk of bleeding

INTRODUCTION

Many anticoagulant drugs target factors common to both the intrinsic and extrinsic coagulation pathways, which may lead to bleeding complications. Since the tissue factor (TF)/factor VIIa complex is associated with thrombosis onset and specifically activates the extrinsic coagulation pathway, compounds that inhibit this complex may provide therapeutic and/or prophylactic benefits with a decreased risk of bleeding.

MATERIALS AND METHODS

The in vitro enzyme profile and anticoagulation selectivity of the TF/VIIa complex inhibitor, ER-410660, and its prodrug E5539 were assessed using enzyme inhibitory and plasma clotting assays. In vivo effects of ER-410660 and E5539 were determined using a TF-induced, thrombin generation rhesus monkey model; a stasis-induced, venous thrombosis rat model; a photochemically induced, arterial thrombosis rat model; and a rat tail-cut bleeding model.

RESULTS

ER-410660 selectively prolonged prothrombin time, but had a less potent anticoagulant effect on the intrinsic pathway. It also exhibited a dose-dependent inhibitory effect on thrombin generation caused by TF-injection in the rhesus monkey model. ER-410660 also reduced venous thrombus weights in the TF-administered, stasis-induced, venous thrombosis rat model and prolonged the occlusion time induced by arterial thrombus formation after vascular injury. The compound was capable of doubling the total bleeding time in the rat tail-cut model, albeit with a considerably higher dose compared to the effective dose in the venous and arterial thrombosis models. Moreover, E5539, an orally available ER-410660 prodrug, reduced the thrombin-anti-thrombin complex levels, induced by TF-injection, in a dose-dependent manner.

CONCLUSION

Selective TF/VIIa inhibitors have potential as novel anticoagulants with a lower propensity for enhancing bleeding.