Management consensus guidance for the use of rivaroxaban – an oral, direct factor Xa inhibitor

A nomogram for predicting major gastrointestinal bleeding in patients treated with rivaroxaban

BACKGROUND

Rivaroxaban is a direct oral anticoagulant with the highest risk of anticoagulant-induced major gastrointestinal bleeding (MGIB). Currently, there is a lack of tools to identify patients at high risk of rivaroxaban-induced MGIB.

OBJECTIVE

To establish a nomogram model to predict the risk of MGIB in patients receiving rivaroxaban.

METHODS

Demographic information, comorbidities, concomitant medications, and laboratory test results were collected from 356 patients (178 diagnosed with MGIB) who were taking rivaroxaban between January 2013 and June 2021. Univariate and multivariate logistic regression analyses were used to identify the independent predictors of MGIB, and a nomogram was constructed based on these predictors. A receiver operating characteristic curve, Brier score, calibration plot, decision curve, and internal validation was used to evaluate the calibration, discrimination, and clinical usefulness of the nomogram.

RESULTS

Age, haemoglobin level, platelet count, creatinine level, prior peptic ulcer disease, prior bleeding, prior stroke, proton pump inhibitor use, and antiplatelet agent use were independent predictors of rivaroxaban-induced MGIB. These risk factors were used to establish the nomogram. The area under the curve of the nomogram was 0.833 (95%CI, 0.782-0.866), the Brier score was 0.171, the internal validation accuracy was 0.73, and the kappa value was 0.46.

CONCLUSION

The nomogram demonstrated good discrimination, calibration, and clinical applicability. Therefore, it could accurately predict the risk of MGIB in patients treated with rivaroxaban.

The impact of anticoagulation therapy on kidney function in patients with atrial fibrillation and chronic kidney disease

INTRODUCTION

Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related. These diseases share common risk factors and are associated with increased risk of thromboembolic events. Choosing the appropriate oral anticoagulant therapy (OAC) in patients with AF and CKD is challenging. Deterioration of renal function is common in patients with AF treated with OACs, although not all OACs affect the kidneys equally.

AREAS COVERED

In this review, we aim to summarize the current knowledge of the prevention of thromboembolic events in patients with AF and CKD, focusing on the impact of specific OAC agents on renal function.

EXPERT OPINION

Consideration of OAC use is mandatory in patients with AF and CKD who are at increased risk of stroke or systemic embolism. Available evidence suggests that the use of non-vitamin K antagonist oral anticoagulants (NOACs) is associated with slower deterioration of renal function in comparison to Vitamin K antagonists (VKAs). Hence, a NOAC should be used in preference to VKAs in all NOAC-eligible patients with AF and CKD. Regarding patients with end-stage renal dysfunction and those on dialysis or renal replacement therapy, the use of NOAC should be considered in line with locally relevant formal recommendations.

Management of Massive Rivaroxaban Overdose With Acetaminophen and Isosorbide Mononitrate Overdose

Direct oral anticoagulants (DOACs) have been used more frequently for the prevention and management of thromboembolic disease in comparison to their predecessors. DOACs provide greater ease of administration, shorter half-lives, less monitoring, and fewer drug-drug interactions. With the rise of DOACs such as rivaroxaban, the opportunity for abuse also increases. Therefore, standardization of care based on rivaroxaban misuse must also be explored, an area in which there is not ample information. We present a case where a patient consumed a stockpile of her home medications in hopes to commit suicide. A 64-year-old female presented to the emergency department due to the ingestion of rivaroxaban 5,000 mg along with ingestion of acetaminophen 30,000 mg and isosorbide mononitrate 1000 mg in the setting of intentional self-harm with multiple declarations of being classified as Do Not Resuscitate. There have been documented cases of rivaroxaban overdose, however, there are no documented cases with levels of ingestion reaching 5,000 mg along with signs of severe bleeding. Our case study reviews the previously documented management of rivaroxaban abuse and the treatment that was given to our patient in the setting of extreme anticoagulant ingestion.

Frequency of hemorrhage after tooth extraction in patients treated with a direct oral anticoagulant: A multicenter cross-sectional study

OBJECTIVE

Few studies have compared the frequency of hemorrhages after tooth extraction between patients taking direct oral anticoagulants (DOACs) and those taking warfarin or no anticoagulants. Further, the effects of the timing of DOAC administration and tooth extraction on the frequency of post-extraction hemorrhage have not been demonstrated. Therefore, we compared the frequency of post-extraction hemorrhages in patients in these different conditions and examined the effects of the timing of DOAC administration and tooth extraction on the frequency.

DESIGN

Prospective multicenter study.

SETTING

Eighty-six Japanese hospitals.

PARTICIPANTS

In total, 182 teeth extracted from 145 individuals (119 teeth from adult males) receiving dabigatran and 88 teeth from individuals (62 teeth from adult males) receiving rivaroxaban were included.

INTERVENTION

Tooth extraction was followed by a 7-day observational period between November 1, 2008 and December 31, 2015. Dabigatran was administered twice daily; rivaroxaban was administered once a day.

PRIMARY OUTCOME MEASURE

Hemorrhage after tooth extraction.

RESULTS

The frequency of hemorrhage after tooth extraction was 1.65%, 3.41%, and 3.63% in those treated with dabigatran, rivaroxaban, and warfarin, respectively, and 0.39% in those who did not receive anticoagulants. Hemorrhages after tooth extraction were significantly higher in the rivaroxaban group than in patients who did not receive anticoagulants (P = 0.008). These frequencies did not differ significantly in the dabigatran and rivaroxaban groups compared to the warfarin group (P = 0.221 and P = 1.000, respectively).

CONCLUSIONS

The frequency of hemorrhaging after tooth extraction appeared to be similar in patients receiving continuous dabigatran or rivaroxaban and in those receiving continuous warfarin.

Effects of direct oral anticoagulants dabigatran and rivaroxaban on the blood coagulation function in rabbits

The aim of this study was to explore the effects of dabigatran and rivaroxaban on the activities of various coagulation factors. To achieve that, 60 rabbits were randomly divided into experimental groups that received different doses of dabigatran or rivaroxaban. The effects of dabigatran and rivaroxaban on the activities of FII, FV, FVIII, FX, and activated protein C (APC) were analyzed. In the dabigatran groups, activated partial thromboplastin time and thromboplastin time (TT) were prolonged after drug administration, and the activities of FII, FV, FVIII, and FX were inhibited as the drug concentration increased. Low doses of dabigatran inhibited APC activity. In the rivaroxaban groups, APTT and TT were not significantly prolonged after drug administration. In contrast, the high-dose rivaroxaban group exhibited prolonged PT, and the degree of inhibition of the activities of FII, FV, FVIII, and FX increased as the drug concentration increased. Rivaroxaban had no significant effect on APC activity regardless of dosage. As the drug concentration increased, both NOACs had more significant inhibitory effects on the activities of FII, FV, FVIII, and FX. Low concentrations of dabigatran generated an inhibitory effect on APC activity, while high concentrations of dabigatran had no significant effect. Rivaroxaban had no significant effect on APC activity.

Safety and Efficacy of Anticoagulation in Patients with Cirrhosis: A Meta-Analysis

BACKGROUND AND AIMS

Portal vein thrombosis is a serious adverse event that occurs during liver cirrhosis. We performed a meta-analysis to evaluate the safety and efficacy of anticoagulant therapy and prophylactic anticoagulant therapy in cirrhosis patients with (/without) portal vein thrombosis.

METHODS

Eligible comparative studies were identified by searching the following electronic databases: PubMed, Embase, Cochrane Library, Web of Science, and CNKI. A meta-analysis was performed to calculate odds ratios and 95% confidence intervals using fixed-effects models. Recanalization and thrombus progression were defined as the primary outcomes. Secondary outcomes included adverse events and death mortality.

RESULTS

A total of 3479 patients were included in this analysis. Compared with the control group, the recanalization rate in the anticoagulant therapy group was increased (P < 0.00001) in patients with cirrhosis and portal vein thrombosis without increasing adverse events. Multiple use of enoxaparin in small doses is safer than single large doses (P=0.004). Direct oral anticoagulants are more effective (P < 0.00001) and safer than traditional anticoagulants. Prophylactic anticoagulant therapy can effectively prevent portal vein thrombosis formation (P < 0.00001).

CONCLUSIONS

Anticoagulation therapy can treat or prevent portal vein thrombosis in patients with liver cirrhosis and is a relatively safe treatment.

Management of Hemorrhage Related to Direct Action Oral Anticoagulant Medication

Introduction: Direct Oral Anticoagulant – DOACs) are a new class of anticoagulant that directly inhibit the trombine (dabigatran) or Xa factor (rivaroxabane , edoxabane and apixabane) in the coagulation cascade. These medications are being more frequently used for the treatment and prevention of thrombolytic events, mainly in patients with atrial fibrillation, in substitute to varfrine or other vitamin K antagonists (VKAs). Although the incidence of hemorrhage is higher in AVKs than in DOACs, these events may also occur in this group, even in the form of intracranial hemorrhage (ICH), with risk of death. Nowadays, DOACs indications have progressively enhanced and the availability of their specific reverse agents certainly will enhance the safety of their usage. Idarucizumab, reverse agent of dabigatrane, and alpha andexanet, reverse agent of Xa factor, have been approved by the Food and Drug Administration in the United States and ciraparantag may be approved in a near future. Objective: To review the literature on the manage of hemorrhage related to the use of DOACs. Methods: Review of literature that used articles from 1998 to 2017, from several platforms and journals. Conclusion: DOACs constitute a great advance in prophylaxis and treatment of thrombolytic diseases, which presents elevated morbidymortality, and hemorrhages are the main adverse events related to their usage, being rarely necessary the immediate reverse of the anticoagulation. However, the existence of DOACs specific reverse agents enhance the safety of patients, whose anticoagulation may be rapidly reversed if necessary.

Manejo das Hemorragias Relacionadas aos Anticoagulantes Orais de Ação Direta

Introdução: Os anticoagulantes orais diretos (direct oral anticoagulant – DOACs) são uma nova classe de anticoagulantes que inibem diretamente a trombina (dabigatrana) ou o fator Xa (rivaroxabana, edoxabana e apixabana) na cascata da coagulação. Esses estão sendo cada vez mais utilizados para tratamento e prevenção de eventos tromboembólicos, principalmente em pacientes com fibrilação atrial, em substituição à varfarina ou outros antagonistas de vitamina K (AVKs). Embora a incidência de hemorragias seja maior nos AVKs do que nos DOACs, elas também podem ocorrer nesse grupo, até mesmo na forma de hemorragia intracraniana (HIC) com risco de morte. Atualmente as indicações dos DOACs vêm aumentando progressivamente, e a disponibilização de seus agentes reversores específicos certamente aumentará a segurança e, consequentemente, sua utilização. O idarucizumab, reversor da dabigatrana, e o andexanet alfa, reversor dos inibidores do fator Xa, foram aprovados pelo Food and Drug Administration (FDA) dos Estados Unidos e o ciraparantag poderá ser aprovado em um futuro próximo. Objetivo: Revisar a literatura sobre o manejo da hemorragia relacionada ao uso dos DOACs. Métodos: Revisão da literatura que utilizou artigos de 1998 a 2017, de diversas plataformas e revistas. Conclusão: Os DOACs constituem um grande avanço na profilaxia e tratamento da doença tromboembólica, que cursa com elevada morbimortalidade, e as hemorragias são os principais eventos adversos relacionados ao seu uso, sendo raramente necessária a reversão imediata da anticoagulação. No entanto, a existência dos reversores específicos dos DOAcs aumenta a segurança dos pacientes, que poderão ter sua anticoagulação revertida rapidamente, se necessário.

Emergency Reversal of Anticoagulation

Owing to the propensity of anticoagulated patients to bleed, a strategy for reversal of anticoagulation induced by any of the common agents is essential. Many patients are anticoagulated with a variety of agents, including warfarin, low molecular weight heparin, and the direct oral anticoagulants such as factor Xa and factor IIa inhibitors. Patients may also be using antiplatelet agents. Recommendations to reverse bleeding in these patients are constantly evolving with the recent development of specific reversal agents. A working knowledge of hemostasis and the reversal of anticoagulation and antiplatelet drugs is required for every emergency department provider. This article reviews these topics and presents the currently recommended strategies for dealing with bleeding in the anticoagulated patient.

The impact of prothrombin complex concentrates when treating DOAC-associated bleeding: a review

Background

Bleeding complications are a risk associated with all anticoagulants. Currently, the treatment options for the management of direct oral anticoagulant (DOAC)-associated bleeding are limited. Prothrombin complex concentrates (PCCs) have been proposed as a potential therapeutic option, and evidence regarding their use is increasing.

Review

Many studies supporting PCC have used preclinical models and healthy volunteers; however, more recently, observational studies have further improved insight into current DOAC reversal strategies. Multiple clinical practice guidelines now specifically suggest use of PCCs for this indication. Specific reversal agents for Factor Xa inhibitors may become available in the near future, but data on their efficacy are still emerging.

Conclusions

Ultimately, a multimodal approach may be the optimal strategy to restore haemostasis in patients presenting with DOAC-associated coagulopathy.

Electronic supplementary material

The online version of this article (10.1186/s12245-018-0215-6) contains supplementary material, which is available to authorized users.

Assessing an oral surgery specific protocol for patients on direct oral anticoagulants: a retrospective controlled cohort study

Chronic therapy with the new direct oral anticoagulants (DOACs) poses new challenges for dental practitioners assessing the risk versus benefit of cessation versus non-cessation of anticoagulant therapy for dentoalveolar procedures. A retrospective controlled cohort study was designed to evaluate a non-cessation protocol for patients taking DOACs in the setting of dental extractions. A records review covering the period 1 January 2016 to 31 December 2016 identified 43 patients on DOAC therapy; 53 dentoalveolar procedures were performed under local anaesthesia, of which 15 included varying degrees of peri-procedural cessation. A control group of 50 patients on uninterrupted warfarin therapy undergoing 59 dentoalveolar procedures was identified. The incidence, severity, and timing of bleeding events were recorded for each group. Four (10.5%) minor bleeding events were recorded in the non-cessation DOAC group and nine (15.3%) minor bleeding events in the warfarin group. No bleeding events were recorded in the DOAC cessation group. Comparison of the incidence of bleeding events between the non-cessation DOAC group and the warfarin group showed no statistically significant difference (odds ratio 0.65, P=0.56). Within the limitations of this study, dental extractions in the context of continuing DOAC therapy can be performed safely provided extra local haemostatic measures are applied.

Efficacy and safety of edoxaban for treatment of portal vein thrombosis following danaparoid sodium in patients with liver cirrhosis

AIM

To compare the efficacy and safety of edoxaban and warfarin for treatment of portal vein thrombosis (PVT) following danaparoid sodium in patients with liver cirrhosis.

METHODS

Fifty cirrhotic patients with PVT treated initially for 2 weeks with danaparoid sodium were enrolled in this retrospective cohort study. Treatment was later switched to either edoxaban (n = 20) or warfarin (n = 30). We compared the efficacy and safety of edoxaban and warfarin for up to 6 months. The PVT volume was measured by dynamic computed tomography before treatment, at 2 weeks, and at 1, 3, and 6 months.

RESULTS

There were no significant differences in the clinical characteristics of patients in the two groups. Treatment with edoxaban reduced the volume of PVT from 1.42 cm³ at 2 weeks to 0.42 cm³ at 6 months, and prevented exacerbation of PVT at 6 months after treatment with danaparoid sodium (P = 0.016). In contrast, treatment with warfarin resulted in increased PVT volume from 1.73 cm³ at 2 weeks to 2.85 cm³ at 6 months, despite the control of the international normalized ratio in 57% of the patients (P = 0.005). Multivariate regression analysis identified edoxaban therapy as the single significant and independent determinant of PVT reduction at 6 months (P = 0.0014, hazard ratio 6.400). Clinically significant gastrointestinal bleeding was encountered in 3 of 20 (15%) patients of the edoxaban group and 2 of 30 (7%) of the warfarin group (P = 0.335).

CONCLUSION

Edoxaban following danaparoid sodium is an effective anticoagulant and could be potentially considered as one of the treatment options for PVT in cirrhotic patients.

Rationale and design of a phase III safety trial of idarucizumab in children receiving dabigatran etexilate for venous thromboembolism

BACKGROUND

The incidence of venous thromboembolism (VTE) in children has been increasing. Anticoagulants are the mainstay of treatment but are associated with bleeding events that may be life-threatening. Idarucizumab is a fragment antigen-binding (fab) that provides immediate, complete, and sustained reversal of dabigatran's anticoagulant effects in adults.

OBJECTIVE AND METHODS

This phase III, open-label, single-arm, multicenter, multinational trial will assess the safety of idarucizumab in children participating in two ongoing trials investigating dabigatran etexilate. Eligible patients will be children with VTE (aged 0-≤18 years; n = ~5) with life-threatening or uncontrolled bleeding (group A), and children who require emergency surgery/urgent procedures for a condition other than bleeding (group B). Patients will receive idarucizumab up to 5 g as two consecutive intravenous infusions over 5-10 minutes each, as two 10-15-minute drips or as two bolus injections (15 minutes apart) and will be monitored for 30 days. The primary endpoint will be the safety of idarucizumab assessed by the occurrence of drug-related adverse events (including immune reactions) and all-cause mortality. Secondary endpoints will be the reversal of dabigatran anticoagulant effects assessed by changes in diluted thrombin time and ecarin clotting time, time to achieve complete reversal and the duration of the reversal and bleeding severity (group A). The formation of antidrug antibodies at 30 days post-dose and cessation of bleeding will also be assessed.

CONCLUSION

This study will report the safety of idarucizumab in children with VTE who require rapid reversal of the anticoagulant effects of dabigatran. Clinical trial registration: NCT02815670.

Comparison of calibrated chromogenic anti-Xa assay and PT tests with LC-MS/MS for the therapeutic monitoring of patients treated with rivaroxaban

Possibilities to monitor rivaroxaban therapy could be useful in certain circumstances. Prothrombin time (PT) or chromogenic anti-Xa assays such as the Biophen Direct Factor Xa Inhibitor® (DiXaI) have been proposed to estimate rivaroxaban concentrations but are mainly based on in vitro studies. The study aim was to compare PT and Biophen DiXaI® measurements with liquid chromatography-tandem mass spectrometry (LC-MS/MS) measurements in plasma samples from patients treated with Xarelto®. Fifty-two plasma samples were included. PT was performed using Innovin® and Triniclot PT Excel S®. Biophen DiXaI® was performed according to instructions from the manufacturer. The rivaroxaban plasma concentration ranged between 0 and 485 ng/ml as measured by LC-MS/MS. The limits of quantification were 30 ng/ml and 5 ng/ml for Biophen DiXaI® and LC-MS/MS, respectively. The linear correlation between Biophen DiXaI® and LC-MS/ MS analyses was high for all rivaroxaban concentrations (r2 = 0.95). For concentrations ≤100 ng/ml, r2-value was 0.83. The Bland-Altman analysis showed a mean difference of −16 ng/ml (SD: 25 ng/ml). The PT methods did not correlate well with plasma concentrations measured by LC-MS/MS (r2 ≈ 0.60). In conclusion, the important interindividual variability and the poor correlation with LC-MS/MS preclude the use of PT to estimate rivaroxaban concentrations. Thanks to its small inter-individual variability and good agreement with LC-MS/ MS measurements, we recommend the use of Biophen DiXaI® assays to estimate concentrations of rivaroxaban >30 ng/ml. Quantification of low rivaroxaban levels (<30 ng/ml) requires the LC-MS/MS method.

The perioperative management of new direct oral anticoagulants: a question without answers

New direct oral anticoagulant agents (DOAC) are currently licensed for thromboprophylaxis after hip and knee arthroplasty and for longterm prevention of thromboembolic events in non-valvular atrial fibrillation as well as treatment and secondary prophylaxis of venous thromboembolism. Some other medical indications are emerging. Thus, anaesthesiologists are increasingly likely to encounter patients on these drugs who need elective or emergency surgery. Due to the lack of experience and data, the management of DOAC in the perioperative period is controversial. In this article, we review available information and recommendations regarding the periprocedural management of the currently most clinically developed DOAC, apixaban, dabigatran, and rivaroxaban. We discuss two trends of managing patients on DOAC for elective surgery. The first is stopping the DOAC 1–5 days before surgery (depending on the drug, patient and bleeding risk) without bridging. The second is stopping the DOAC 5 days preoperatively and bridging with low-molecular-weight heparin. The management of patients on DOAC needing emergency surgery is also reviewed. As no data exist for the use of haemostatic products for the reversal of the anticoagulant effect in these cases, rescue treatment recommendations are proposed.

Novel Oral Anticoagulants in the Peri-Endoscopic Period

Millions of patients in the United States are currently prescribed some form of anticoagulation therapy. Recently, novel oral anticoagulants (NOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, have begun to replace warfarin as the drugs of choice for anticoagulation. As the use of these medications becomes more widespread, it is increasingly important for gastroenterologists to understand the risks associated with performing endoscopic procedures on patients who are taking NOACs. In this review, we provide an overview of the NOACs and current guidelines from international societies regarding the management of patients scheduled to undergo endoscopic procedures who are prescribed these medications. Finally, we offer a perspective on future studies required to adequately investigate and characterize the effects that these drugs have on a patient's risk for bleeding in the peri- and/or postprocedural timeframes.

Anticoagulant activity of oral rivaroxaban in healthy dogs

Rivaroxaban is an oral, direct factor Xa inhibitor used in human thrombotic disorders. In view of the in vitro concentration dependent anticoagulant effects of rivaroxaban in dogs, the time course of its anticoagulant effects was characterized in healthy dogs. Twenty-four healthy Beagles were randomized into three groups (n = 8 per group) and received orally either a placebo or 20 mg rivaroxaban once or twice at an 8 h interval. Fifteen blood samples were collected over a 30 h period, and blindly assayed for prothrombin time (PT), activated partial thromboplastin time (aPTT), tissue factor induced thrombin generation (TG) and anti-factor Xa activity. Thromboelastography (TEG) was evaluated at 0, 1, 4, 8 and 24 h. Peak/baseline anticoagulant effect ratios were analyzed with generalized linear models using β distributions and times to return to baseline with survival analyses (α = 0.05). Peak/baseline anticoagulant effect ratios of PT, aPTT, anti-factor Xa activity, TG and R (TEG) differed significantly between placebo and both rivaroxaban groups (P <0.0001). The peak anticoagulant effect of rivaroxaban occurred 1.5 to 2 h after dosing. The median return to baseline occurred significantly sooner (P <0.01) with 20 mg rivaroxaban administered once (7.9-18.7 h) versus twice (17.5-26.8 h). The inter-individual variability differed amongst assays, but overall was moderate to large. No adverse effects were recorded. Twice oral administration of 2 mg/kg rivaroxaban at an 8 h interval maintained 24 h anticoagulant activity, but larger studies are needed to establish guidelines for the use of rivaroxaban in dogs.

Rivaroxaban for Thromboprophylaxis After Nonelective Orthopedic Trauma Surgery in Switzerland

This study investigated the effectiveness and the outcomes of rivaroxaban vs the standard of care for venous thromboembolic prophylaxis in patients undergoing fracture-related surgery. A total of 413 patients undergoing fracture-related surgery from 9 Swiss orthopedic and trauma centers were enrolled. The authors selected the type of venous thromboembolic prophylaxis according to standardized medical practice at the participating centers before the inclusion of patients: 208 patients received rivaroxaban and 205 received the standard of care. Data on symptomatic thromboembolic and bleeding events, surgery-related complications, death, adverse events, time to mobilization, and hospital discharge were collected. Symptomatic thromboembolic events were reported in 1 patient (0.5%) and 2 patients (1.0%) and treatment-emergent major bleeding events were reported in 1 patient (0.5%) and 2 patients (1.0%) receiving rivaroxaban and the standard of care, respectively. The durations of hospital stay and venous thromboembolic prophylaxis were similar in the 2 groups. In both groups, adverse events related to venous thromboembolic prophylaxis were reported in 12 patients. The proportion of patients with minor and major fracture surgery was 74.3% and 25.7%, respectively. In patients undergoing minor fracture surgery receiving rivaroxaban (n=167) and the standard of care (n=140), no symptomatic thromboembolic events and no major bleeding events were reported. Outcomes of this study indicate that rivaroxaban might be an appropriate oral alternative for venous thromboembolic prophylaxis in routine medical care after fracture-related major and minor surgery. Reported results were comparable to those from other large-scale, noninterventional and randomized controlled studies. [Orthopedics. 2017; 40(2):109-116.].

Use of rivaroxaban in patients with stroke

Rivaroxaban, an inhibitor of Factor Xa, is a direct oral anti-coagulant that has been found to be non-inferior to warfarin in preventing cerebral ischemia in patients with non-valvular atrial fibrillation and in the subgroup of patients with a history of the previous stroke or transient ischemic attack. Vascular neurologists in daily clinical practice may encounter patients taking rivaroxaban or patients who may benefit from its use. In this paper, we review the current clinical indications, contraindications, and clinical management guidelines for rivaroxaban while providing a special focus on neurological aspects and expert opinions on rivaroxaban therapy management in various situations that a neurologist may encounter when treating patients with an ischemic stroke (including those requiring intravenous or intra-arterial reperfusion therapy) and patients with an intracerebral hemorrhage. Since data from clinical trials and real-life data are missing in some clinical situations, strong recommendations are not always available. Nevertheless, practical guidelines should be adopted to maximize benefits from this oral anti-coagulant.

Rivaroxaban for venous thromboembolism prevention after major orthopedic surgery: translating trial data into routine clinical practice

An established standard of care for the prevention of venous thromboembolism after major orthopedic surgery has been subcutaneous low-molecular-weight heparin. The non-vitamin K antagonist oral anticoagulant rivaroxaban has demonstrated superior efficacy and similar safety to all tested regimens of enoxaparin in large Phase III clinical studies of venous thromboembolism prevention after elective hip and knee arthroplasty. Despite regulatory approval of rivaroxaban for this indication, concerns remain among physicians regarding its optimal and effective use in routine clinical practice. Real-life studies, such as XAMOS and ORTHO-TEP, are providing physicians with more information on the routine use of rivaroxaban for venous thromboembolism prevention after orthopedic surgery, helping to establish its safety and effectiveness in everyday clinical care. Among the most important issues are the risk of bleeding complications, wound healing, timing of first dose, impact of type of anesthesia on thromboprophylaxis effectiveness, patient comorbidities and comedication use, periprocedural management, associated costs, and clinical outcomes in trauma-related fractures. Many of these issues are difficult to study in randomized, double-blind, Phase III trials, and can be assessed more readily using real-life data. In particular, real-life or noninterventional studies lack many of the strict inclusion and exclusion criteria associated with Phase III trials and involve unselected patients who often present with significant comorbidities or comedication use.

Perioperative Management of Anticoagulation-Review of Latest Evidence

Periprocedural anticoagulation bridging is recommended to reduce the risk of thromboembolic events in patients at a higher risk of developing thromboembolism during the perioperative period. The optimal periprocedural anticoagulation strategy has not been established. Unfractionated heparin and low molecular heparin are used in preventing thromboembolism in the special population. Novel oral anticoagulants that directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban) are shown as effective anticoagulants in preventing thromboembolism (venous thromboembolism) in various medical conditions. They have the advantage of having a faster onset, shorter half-lives, easier monitoring, and predicable doses. But there are disadvantages to newer anticoagulants such as the unavailability of definitive reversal agents and lack of data in patients with renal insufficiency. We review the latest evidence on the effects of newer oral anticoagulants in preventing thromboembolism and its bleeding risks.

Perioperative Management of Direct Oral Anticoagulants (DOACs): A Systemic Review

Direct oral anticoagulants (DOACs) are in wide use among patients requiring both short- and long-term anticoagulation, mainly due to their ease of use and the lack of monitoring requirements. With growing use of DOACs, it is imperative that physicians be able to manage patients on these medications, especially in the perioperative period. We aim to provide guidance on the management of DOACs in the perioperative period. In this review, we performed an extensive literature search summarizing the management of patients on direct-acting anticoagulants in the perioperative period. A total of four direct-acting oral anticoagulants were considered appropriate for inclusion in this review. The drugs were dabigatran etexilate mesylate (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa). Management of patients on DOACs in the perioperative period involves an assessment of thromboembolic event risk while off anticoagulation compared to the relative risk of bleeding if such drug is continued. DOACs may not need to be discontinued in minor surgeries or procedures, and in major surgeries, they may be discontinued hours prior depending on drug pharmacokinetics and renal function of the patients.

Massive intoxication with rivaroxaban, phenprocoumon, and diclofenac: A case report

RATIONALE

Oral anticoagulants and painkillers, some with an additional effect on the coagulation system, are widely used and are therefore prone to abuse and (intentional) overdose. We report the case of a patient with a massive mixed anticoagulant intoxication.

PATIENT CONCERNS

The patient had ingested 1960 mg rivaroxaban, 31.5 mg phenprocoumon, 1425 mg diclofenac, and 21,000 mg metamizole in suicidal intention.

DIAGNOSES

Massive mixed anticoagulant overdose.

INTERVENTIONS

The patient was closely monitored. The phenprocoumon overdose was treated by the administration of vitamin K and PCC.

OUTCOMES

Despite the massive inhibition of the coagulation system, the patient did not experience bleeding apart from a slight gross hematuria.

LESSONS

Despite the ingestion of a massive amount of rivaroxaban, the plasma levels were not as high as feared, due to the ceiling effect of rivaroxaban absorption. Elimination occurred according to the half-life of rivaroxaban and was not unduly prolonged by the ingested quantity.

Novel Oral Anticoagulants for Venous Thromboembolism with Special Emphasis on Risk of Hemorrhagic Complications and Reversal Agents

Warfarin was the only oral anticoagulant available for the treatment of venous thromboembolism for about half a century until the recent approval of novel oral agents dabigatran, rivoraxaban and apixaban. This presents new classes of medications less cumbersome to use. They do not require frequent laboratory monitoring or have nurmerous drug interactions. On the other hand it also poses a challenge to the physicians deciding which agent to use in specific patient populations, how to predict the bleeding risk compared to warfarin and between the different novel agents and how to manage bleeding with relatively recent discovery of few potential antidotes. This review summarizes the major trials that led to the approval of these agents and their exclusion criteria helping physicians understand which patient types might not benefit from these agents. It provides clinical pearls invaluable in everyday practice such as transitioning between traditional and novel anticoagulants, dose adjustments for high risk populations, drug interactions and cost analysis. Futhermore, the review provides direct comparisons with warfarin and indirect comparisons among the novel agents in terms of efficacy and bleeding risk narrating the numbers of patients with intracranial, gastrointestinal and fatal hemorrhages in each of the major trials. We hope that this review will help the physicians inform their patients about the benefits and risks of these agents and enable them to make an informed selection of the most appropriate anticoagulant.

Management of novel oral anticoagulants in emergency and trauma surgery

BACKGROUND

The compelling safety, efficacy and predictable effect of novel oral anticoagulants (NOACs) is driving a rapid expansion in their therapeutic indications. Management of the increasing number of patients on those new agents in the setting of emergency or trauma surgery can be challenging and the absence of specific reversal agents has been a matter of concern. This review summarises the key principles that underpin the management of those patients with a particular emphasis on the recent development of specific antidotes.

FINDINGS

As of 2015, a new line of antidotes, specific for these drugs, are at different stages of their development with their release imminent. However, as NOACs are innately reversible due to their short half-life, the use of reversal agents will probably be restricted to a few exceptional cases. Post-marketing surveillance will be paramount to better clarify the role of these promising drugs.

CONCLUSIONS

Management of patients on NOACs in the context of emergency or trauma surgery relies on best supportive care in combination with the blood products and/or specific antidotes as required. Familiarity with the new reversal agents is essential but further evidence on their indications, safety and efficacy as well as consensus guidelines are warranted prior to widespread adoption.

The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were reconsidered and revised based on new scientific evidence and observed shifts in clinical practice; new recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.

Serpentine-like right atrial mass and fulminant bilateral pulmonary embolism during treatment with rivaroxaban

Imaging work-up of a 80-year-old woman with sudden onset of dyspnea during current rivaroxaban therapy: computer tomography angiography revealed fulminant bilateral pulmonary embolism. Furthermore, a serpentine-like huge mass in the right atrium was detected, highly suggestive of thrombus or a giant chiari network, respectively. This case highlights the importance of adequate dose regimen of factor Xa inhibitors, as well as the need of thorough differential diagnostic considerations of net like structures in the right atrium.

Deep Vein Thrombosis in the Lower Extremities in Comatose Elderly Patients with Acute Neurological Diseases

PURPOSE

Comatose elderly patients with acute neurological illness have a great risk of deep vein thrombosis (DVT). In this study, the incidence of DVT and the effectiveness of early initiation of treatment were evaluated in those patients.

MATERIALS AND METHODS

Total 323 patients were admitted to our ward due to neurological diseases in one year, and 43 patients, whose Glasgow Coma Scale was ≤ 11 and who was older than ≥ 60 years, were included in this study. D-dimer was measured on admission and day 7, and lower-extremity ultrasonography was performed on day 7. When DVT was positive, heparin treatment was initiated, and further evaluation of pulmonary embolism (PE) was conducted. Vena cava filter protection was inserted in PE-positive patients. Incidence of DVT and PE, alteration of D-dimer value, and effect of heparin treatment were analyzed.

RESULTS

DVT was positive in 19 (44.2%) patients, and PE was in 4 (9.3%). D-dimer was significantly higher in DVT-positive group on day 7 (p<0.01). No DVT were identified in patients with ischemic disease, while 66.7% of intracerebral hemorrhage and 53.3% of brain contusion patients were DVT positive. Surgery was a definite risk factor for DVT, with an odds ratio of 5.25. DVT and PE disappeared by treatment in all cases, and no patients were succumbed to the thrombosis.

CONCLUSION

Patients with hemorrhagic diseases or who undergo operation possess high risk of DVT, and initiation of heparin treatment in 7 days after admission is an effective prophylaxis for DVT in comatose elderly patients without causing bleeding.

Managing patients taking novel oral anticoagulants (NOAs) in dentistry: a discussion paper on clinical implications

Background

The aim of this paper is to contribute to the discussion on how to approach patients taking new orally administered anticoagulants (NOAs) dabigatran etexilate (a direct thrombin inhibitor), rivaroxaban and apixaban (factor Xa inhibitors), before, during and after dental treatment in light of the more recent knowledges.

Discussion

In dentistry and oral surgery, the major concerns in treatment of patients taking direct thrombin inhibitors and factor Xa inhibitors is the risk of haemorrhage and the absence of a specific reversal agent. The degree of renal function, the complexity of the surgical procedure and the patient’s risk of bleeding due to other concomitant causes, are the most important factors to consider during surgical dental treatment of patients taking NOAs. For patients requiring simple dental extraction or minor oral surgery procedures, interruption of NOA is not generally necessary, while an higher control of bleeding and discontinuation of the drug (at least 24 h) should be requested before invasive surgical procedures, depending on renal functionality.

Summary

The clinician has to consider that the number of patients taking NOAs is rapidly increasing. Since available data are not sufficient to establish an evidence-based dental management, the dentist must use caution and attention when treating patients taking dabigatran, rivaroxaban and apixaban.

How to manage patients on rivaroxaban in the emergency department: a statement of the Italian society of emergency medicine advisory board

Rivaroxaban, a new oral anticoagulant, has been approved in many countries and its everyday use in clinical practice is increasing. Thus, the chances for an emergency physician to encounter rivaroxaban-treated patients in emergency situations have increased. Here, the authors address the main issues in terms of the prescription of rivaroxaban and the management of these patients in cases of minor or major bleeding, urgent surgery, atrial fibrillation requiring cardioversion, acute ischemic stroke, ST-elevation myocardial infarction, and new onset of atrial fibrillation in recent ST-elevation myocardial infarction. The recommendations reached are based on a literature review and a panel discussion of the advisory board of SIMEU, the Italian Society of Emergency Medicine.

Direct oral anticoagulants: new drugs and new concepts

Direct oral anticoagulants (DOACs) are approved for multiple thromboembolic disorders and provide advantages over existing agents. As with all anticoagulants, management protocols for the eventuality of bleeding are important. Randomized phase III studies generally show that DOACs have a similar risk of clinically relevant bleeding compared with standard anticoagulants, with reductions in major bleeding in some cases. This may be particularly important in patients with atrial fibrillation, for whom the rate of intracranial hemorrhage was approximately halved with DOACs compared with warfarin. Conversely, the risk of gastrointestinal bleeding may be increased. Specific patient characteristics, such as renal impairment, comedications, and particular aspects of each drug, including the proportion eliminated by the kidneys, must be taken into account when assessing the risk of bleeding. Although routine coagulation monitoring of DOACs is not required, it may be useful under some circumstances. Of the traditional clotting assays, a sensitive and calibrated prothrombin time may be useful for detecting the presence or absence of clinically relevant factor Xa inhibitor concentrations (rivaroxaban or apixaban), but specific anti-factor Xa assays can measure drug levels quantitatively. For dabigatran, the results of an activated partial thromboplastin time test may exclude a clinically relevant pharmacodynamic effect, but a calibrated dilute thrombin time assay can be used for quantification of drug levels. In the event of mild or moderate bleeding, normal hemostatic support measures are recommended. For life-threatening bleeding, use of nonspecific prohemostatic agents may be considered, although clinical evidence is scarce. Specific antidotes are in development.

Pregnancy outcome after exposure to the novel oral anticoagulant rivaroxaban in women at suspected risk for thromboembolic events: a case series from the German Embryotox Pharmacovigilance Centre

BACKGROUND

New oral anticoagulants are increasingly used in women of childbearing age, but apart from one case report there is no published experience with rivaroxaban exposure during pregnancy.

METHODS

From October 2008 to December 2014, the German Embryotox Pharmacovigilance Centre identified 63 exposed pregnancies among 94 requests concerning rivaroxaban use during childbearing age. Follow-up included paediatric checks until 6 weeks after birth.

RESULTS

All pregnancies with completed follow-up were exposed at least during the first trimester. Treatment indications included venous thromboembolism, knee surgery, and atrial fibrillation. 37 pregnancies were prospectively ascertained and resulted in six spontaneous abortions, eight elective terminations of pregnancy, and 23 live births. All women had discontinued rivaroxaban after recognition of pregnancy, mostly in the first trimester, but in one woman treatment continued until gestational week 26. There was one major malformation (conotruncal cardiac defect) among the 37 prospectively ascertained pregnancies in a woman with complex medication and a previous foetus with cardiac malformation without exposure to rivaroxaban. Only one case of bleeding concerning a retrospective report of surgery for missed abortion was observed in our case series.

CONCLUSION

Our results might give reassurance to those women, who were inadvertently exposed to rivaroxaban in early pregnancy. However, our limited cohort size does not allow ruling out an increased malformation risk and does not support the use of rivaroxaban during pregnancy. In all cases of (inadvertent) rivaroxaban exposure during 1st trimester, anticoagulation regimen should be reconsidered and a detailed ultrasound assessment recommended to confirm normal foetal development.

Aspirin and heparin in pregnancy

INTRODUCTION

A pro-coagulant state during pregnancy can be involved in the occurrence of gestational vascular complications (GVCs) and venous thromboembolism (VTE).

AREAS COVERED

Antithrombotic drugs are used to prevent GVCs and VTE. Aspirin is not efficacious to prevent recurrences in women with previous early loss, while it can prevent pre-eclampsia in some groups of women. Heparins are not effective in the prevention of early recurrent loss and there is uncertainty about their efficacy in women carrying inherited thrombophilias. They could be efficacious in the prevention of GVCs in carriers of inherited thrombophilias, as GVCs have heterogeneous causes, and future studies have to focus on more homogeneous groups of patients. Not enough data are available regarding prophylaxis with heparins to prevent pregnancy-related VTE, but an accurate risk stratification of women during pregnancy and puerperium is crucial for administering prophylaxis in moderate-/high-risk women. Aspirin does not improve live births after assisted reproductive technologies, while heparins increase the number of clinical pregnancies and live births.

EXPERT OPINION

Aspirin is efficacious in the prevention of GVCs in women at risk for pre-eclampsia and in those with antiphospholipid antibodies syndrome. Heparins could give benefit to women at risk for GVCs and/or pregnancy-related VTE.

Rivaroxaban for the treatment and prevention of thromboembolic disease

Objectives

A number of direct oral anticoagulants are now available and offer alternative strategies for anticoagulation therapy. Rivaroxaban, a direct oral Factor Xa inhibitor, is approved for use across several thromboembolic indications. This article aims to provide an overview of the key pharmacological characteristics of rivaroxaban and the rationale and evidence for the use of different dose regimens across its licenced indications, and offer practical guidance to healthcare professionals on responsible use. References were sourced via PubMed searches using the search string (rivaroxaban AND (pharmacokinetics OR pharmacodynamics OR (clinical studies) OR (drug interaction)) NOT review NOT (children OR pediatrics OR paediatrics OR adolescent)).

Key findings

Rivaroxaban exhibits predictable pharmacokinetics and pharmacodynamics, and thus does not require routine coagulation monitoring, unlike vitamin K antagonists (e.g. warfarin). Rivaroxaban also has a lower potential for drug–drug and food–drug interactions compared with warfarin; however, co-administration with strong inhibitors of both cytochrome P450 3A4 and P-glycoprotein is not recommended. The data indicate that dose adjustment is not necessary for age, gender or body weight. The dosing regimens of rivaroxaban vary depending on the indication, and phase III studies have demonstrated a favourable benefit–risk profile of rivaroxaban compared with traditional standard of care.

Summary

Rivaroxaban may offer an anticoagulant option that could simplify and improve the management of patients with thromboembolic disorders.

Reversal of oral factor Xa inhibitors by prothrombin complex concentrates: a re-appraisal

Oral factor Xa inhibitors are an attractive class of anticoagulants expected to have broad application. Rapid and reliable reversal of the anticoagulant effect is important for patients with bleeding complications or those in need of urgent reversal for procedures. While no specific reversal agent is yet available, multiple published clinical guidelines suggest that four-factor prothrombin complex concentrates (PCC) should be considered when urgent reversal is desired. This presentation updates prior reviews on this topic (Crit Care, 17, 2013, 230; Thromb Haemost, 111, 2014, 189; J Thromb Thrombolysis, 2015, 39, 395); and summarizes more recent evidence in human studies indicating that four-factor PCCs available in North America do not reverse oral factor Xa-inhibitor anticoagulants. New agents on the horizon appear to be far more promising as therapies for reversal or oral factor Xa inhibitors.

Non-VKA Oral Anticoagulants: Accurate Measurement of Plasma Drug Concentrations

Non-VKA oral anticoagulants (NOACs) have now widely reached the lucrative market of anticoagulation. While the marketing authorization holders claimed that no routine monitoring is required and that these compounds can be given at fixed doses, several evidences arisen from the literature tend to demonstrate the opposite. New data suggests that an assessment of the response at the individual level could improve the benefit-risk ratio of at least dabigatran. Information regarding the association of rivaroxaban and apixaban exposure and the bleeding risk is available in the drug approval package on the FDA website. These reviews suggest that accumulation of these compounds increases the risk of experiencing a bleeding complication. Therefore, in certain patient populations such as patients with acute or chronic renal impairment or with multiple drug interactions, measurement of drug exposure may be useful to ensure an optimal treatment response. More specific circumstances such as patients experiencing a haemorrhagic or thromboembolic event during the treatment duration, patients who require urgent surgery or an invasive procedure, or patient with a suspected overdose could benefit from such a measurement. This paper aims at providing guidance on how to best estimate the intensity of anticoagulation using laboratory assays in daily practice.

Discovery of Intra-Abdominal Hemorrhage during Hernioplasty in a Patient Taking Rivaroxaban

We discuss the first ever case of rivaroxaban causing major intra-abdominal hemorrhage found in a patient during emergency hernioplasty. The source of bleeding was not identified either intra- or postoperatively. This is on a background of treatment for deep vein thrombosis (DVT) with rivaroxaban, a complication that resulted from a total knee arthroplasty performed four weeks prior. Rivaroxaban is a new generation of anticoagulants that directly inhibits factor Xa and is used for DVT treatment in major orthopaedic surgery. Here we discuss the major side effects of rivaroxaban, namely, the increased risk of major bleeding as well as the irreversibility of this anticoagulant, should such bleeding occur. We advise caution in the use of rivaroxaban even in patients that are at low risk of bleeding given the discovery of hemorrhage as presented in this case.

Tonsillectomy on rivaroxaban

OBJECTIVE

The objective of this case report is to increase awareness regarding a new category of drugs, new direct oral anticoagulants (specifically, rivaroxaban), which are increasingly being used instead of the more traditional vitamin K antagonists, to highlight the current recommendations for perioperative management of rivaroxaban, and to demonstrate a clinical scenario where a tonsillectomy was successfully performed in a patient requiring anticoagulation with rivaroxaban.

METHODS

A literature review and a case report are presented. PubMed was reviewed for evidence based recommendations regarding the perioperative management of rivaroxaban and the recommendations for reversal in the event of a hemorrhagic complication. There is no evidence in the literature regarding the use of rivaroxaban in patients undergoing tonsillectomy. We present the case of a 38year old female on rivaroxaban for history of deep vein thrombosis and pulmonary embolism who successfully underwent tonsillectomy using the current recommendations for perioperative management of rivaroxaban.

RESULTS

Our patient had no thrombotic or hemorrhagic complications during the postoperative period. This is the first report in the literature regarding the use of a new direct oral anticoagulant, rivaroxaban, in the setting of tonsillectomy. This case report suggests that tonsillectomy can be performed in patients anticoagulated with rivaroxaban.

CONCLUSION

With the increasingly common use of new direct oral anticoagulants for short and long-term anticoagulation, further research is necessary to compare the efficacy and safety profile of the new direct oral anticoagulants to the more traditional vitamin K antagonists when performing tonsillectomy. Otolaryngologists should be familiar with the new oral anticoagulants and understand the proposed perioperative management as practitioners are increasingly likely to encounter patients using this new class of medication in clinical practice.