Rivaroxaban in the contemporary treatment of acute coronary syndromes

A case report describing a suspected rivaroxaban hypersensitivity reaction in a surgical patient

WHAT IS KNOWN AND OBJECTIVE

Rivaroxaban is an oral anticoagulant, currently licensed for use as a venous thromboembolism (VTE) prophylaxis, and recommended by the National Institute for Clinical Excellence (NICE) for all patients undergoing elective hip and knee replacement surgery in the UK. We present the first case of a suspected hypersensitivity to rivaroxaban.

CASE SUMMARY

A 57-year-old man with no previous allergies underwent an uncomplicated, elective partial knee replacement, after which he was prescribed a routine 2-week course of rivaroxaban 10 mg. He developed an allergic response requiring readmission for assessment and treatment 7 days post-operatively.

WHAT IS NEW AND CONCLUSION

We believe this to be the first published case of hypersensitivity associated with rivaroxaban. More research is needed to determine this association. At the same time, given the growing range and increasing use of anticoagulants, particular vigilance is required regarding potential side effects so that these may be managed quickly and effectively in the early stages.

The emergence of factor Xa inhibitors for the treatment of cardiovascular diseases: a patent review

INTRODUCTION

Factor Xa (FXa) is a critical enzyme in the coagulation cascade responsible for thrombin generation, the final enzyme that leads to fibrin clot formation. Significant success has recently been reported with compounds such as rivaroxaban, apixaban and edoxaban in the treatment and prevention of venous thromboembolism (VTE) and more recently in the prevention of stroke in atrial fibrillation (AF). The success these agents have demonstrated is now being reflected by a narrowing of new FXa patents over the past few years. The new patents appear to be structural modifications of previously published, small molecule inhibitors and bind in a similar manner to the FXa enzyme.

AREAS COVERED

SciFinder®, PubMed and Google websites were used as the main source of literature retrieval. Patent searches were conducted in the patent databases: HCAPlus, WPIX and the full text databases (USPAT2, USPATFULL, EPFULL, PCTFULL) using the following keywords: ((FXa) OR (F OR factor) (W) (Xa)) (S) (inhibit? or block? or modulat? or antagonist? or regulat?). The search was restricted to patent documents with the entry date on or after 1 January 2009. Literature and information related to clinical development was retrieved from Thomson Reuter's Pharma.

EXPERT OPINION

A large body of Phase II and Phase III data is now available for FXa inhibitors such as rivaroxaban, apixaban, edoxaban and betrixaban. The clinical data demonstrate favorable benefit-risk profiles compared with the standards of care for short- and long-term anticoagulation (i.e., low molecular weight heparins (LMWHs) and wafarin). The potential exists that these agents will eventually be the agents of choice for the treatment of a host of cardiovascular disease states, offering improved efficacy, safety, and ease of use compared with existing anticoagulants.

Improving long-term ACS management: is there a role for the new antiplatelets?

Acute coronary syndrome (ACS) is a major health burden, resulting in increased hospital admissions and significant morbidity and mortality. Platelet activation, which leads to thrombin generation, is highly implicated in ACS, and antiplatelet agents represent the current standard of care. Established antiplatelet agents include acetylsalicylic acid (ASA), thienopyridines (clopidogrel, ticlopidine), and glycoprotein IIb/IIIa inhibitors. Recently, antiplatelet therapy for ACS has evolved to include more potent inhibitors (e.g., prasugrel, cangrelor, and ticagrelor). During the acute phase of an acute coronary event, both anticoagulation and dual antiplatelet therapy with aspirin and a thienopyridine are guideline recommended as first-line treatment. While anticoagulation is usually limited to the acute in-patient phase, dual antiplatelet therapy is recommended for 12 months. Despite the efficacy of antiplatelet agents in ACS, in many patients the residual risk of death from cardiac events, myocardial infarction, stroke, and refractory ischemia remains high. Dual therapy (i.e., ASA or clopidogrel plus a vitamin K antagonist [VKA]), and triple therapy (two antiplatelets plus a VKA) are associated with increases in bleeding complications. New oral anticoagulants that offer a novel mechanism of action may, when added to the current standard of care, provide a more comprehensive response to thrombin generation. In this review, we examine the pathology of ACS, investigate antiplatelet therapies and describe emerging anticoagulants that may be of benefit when used as combination therapy with antiplatelet agents for secondary prevention in ACS patients.