Therapeutic potential of apixaban in the prevention of venous thromboembolism in patients undergoing total knee replacement surgery

New horizons in anticoagulation: Direct oral anticoagulants and their implications in oral surgery

BACKGROUND

Thrombotic disorders remain a leading cause of death in the Western World. For decades, vitamin K antagonists used in the prevention of this pathology, such as warfarin or sintrom, were the only oral agents available for long-term anticoagulation, in spite of their disadvantages.

MATERIAL AND METHODS

An electronic database search was carried out on MedLine and The Cochrane Library Plus, without restrictions on the type of study nor dates, in English and Spanish. Abstracts were reviewed, and complete articles if necessary, considering all articles that included recommendations on DOACs and oral surgery.

RESULTS

In recent years, the so-called "new oral anticoagulants" have been introduced in clinical practice to treat those patients whose medical conditions require long-term anticoagulant treatment, replacing traditional oral anticoagulants.

CONCLUSIONS

The new oral anticoagulants represent new therapeutic options, with a number of advantages such as poor interaction with food, minor drug interactions, and do not require periodic dose adjustments or routine controls. The purpose of this review is to establish an update on the new oral anticoagulants: Dabigatran, Rivarozaban, Apixaban and Edoxaban.

Implications of apixaban for dental treatments

Background

Anticoagulation therapy is used in several conditions to prevent or treat thromboembolism. Recently, new oral anticoagulants have been introduced as alternatives to warfarin and acenocoumarol. In Europe, the European Medicines Agency has approved dabigatran, rivaroxaban and apixaban. Their advantages include: predictable pharmacokinetics, drug interactions and limited food, rapid onset of action and short half-life. However, they lack a specific reversal agent.

Material and Methods

A literature search was conducted through November 2015 for publications in the ISI Web of Knowledge, PubMed, Scopus and Cochrane Library using the keywords “apixaban”, “rivaroxaban”, “dabigatran”, “new oral anticoagulants”, “dental treatment” and “dental implications”. We included studies published in English and Spanish over the last 10 years.

Results

Apixaban has been recently introduced in the daily medical practices for the control of thromboembolism. The number of patients taking apixaban is increasing. Management of patients on anticoagulation therapy requires that dentists can accurately assess the patient prior to dental treatments. It is important for dentists to have a sound understanding of the mechanisms of action and management guidelines for patients taking new oral anticoagulants.

Conclusions

The dentist should consider carefully the management of patients on apixaban. This paper sets out a clinical guidance of dental practitioners treating these patients. There is a need for further clinical studies in order to establish more evidence-based guidelines for dental patients requiring apixaban.

Key words:Apixaban, new oral anticoagulants, dental treatment.

Reducing the risk of venous thromboembolism using apixaban - patient perspectives and considerations. Should more attention be given to females?

BACKGROUND

New oral anticoagulant agents, such as apixaban, rivaroxaban, dabigatran, or endoxaban, have recently become for patients an alternative option to conventional treatment in the therapy of venous thromboembolism (VTE). Thus, we aimed to review the available information on adverse events (AEs) of apixaban compared to conventional therapy (heparin or vitamin K antagonists) in randomized controlled trials (RCTs) on patients treated for VTE, with a particular attention to sex subgroups.

METHODS

An electronic search in MEDLINE and Embase was performed by using the keywords "apixaban" and "venous thromboembolism". All RCTs focused on apixaban in the treatment and prevention of VTE were evaluated for the presence of AEs. AEs were classified as serious, bleeding, and cause of discontinuation. Moreover, we also searched by using the keywords "gender" and "venous thromboembolism" and "anticoagulants".

RESULTS

Considering all subjects enrolled in the eleven RCTs as a whole to investigate the occurrence of AEs, we extrapolated an events/subjects rate of 57.8% for AEs (6,445/11,144), 7.7% for serious AEs (975/12,647), 9.1% for bleeding events (1,229/13,454), and 3.2% for discontinuation of apixaban (421/13,039). The percentage of AEs was lower in subjects treated with apixaban than in those treated with conventional VTE therapy (53% vs 56.3%, respectively). However, only one study provided data on separate analysis by sex of either efficacy or safety of apixaban.

CONCLUSION

Under the patient's perspective, apixaban could represent a good choice in the treatment of VTE, due to its pharmacological, economical, and safety profile. These positive aspects are certainly present in both sexes, since the available studies include a correct percentage of women, but data with separate analyses by sex are extremely limited. Future clinical trials should include in their results on clinical impact and outcomes a stratification by sex, and studies aimed to evaluate possible sex-related differences for these drugs should be strongly encouraged.

Apixaban and oral implications

Background

Thrombotic disorders remain a leading cause of death in the Western world, and in this regard a number of anticoagulation treatment have been used, including heparins, fondaparinux, vitamin K antagonists (warfarin, acenocoumarol), and new oral anticoagulants such as apixaban. For years there has been great controversy regarding the use of anticoagulants in planning dental treatments that imply bleeding. The main concerns about using new oral anticoagulants in invasive dental procedures are bleeding due to the lack of an antidote, and the thrombotic risk of the disease for which anticoagulation was indicated in the first place.

Material and Methods

A literature search was conducted through May 2014 using the keyword “apixaban” for publications in the ISI Web of Knowledge. The search was extended to other databases (PubMed, Scopus and the Cochrane Library).

Results

Based on the results of the different studies, apixaban seems to be a good alternative to conventional anticoagulation and a reasonable treatment option, though its main and most common adverse effect is bleeding. Dose adjustment is needed in some patients, though regular laboratory monitoring is not required. The use of the drug in different patient populations will define its final indications and doses.

Conclusions

Regarding the use of apixaban in the dental setting, there is a compelling need for further clinical studies in order to establish more evidence-based guidelines for patients requiring antithrombotic treatment.

Key words:Apixaban, dental treatment, dental implications.

Apixaban versus enoxaparin in elective major orthopedic surgery: a clinical review

Despite current guidelines recommendations about anticoagulant prophylaxis, many studies have shown an high venous thromboembolism (VTE) incidence in patients undergoing total hip and knee arthroplasty. A number of anticoagulants are currently available, but they have some limitations that affect their applicability and consequently their effectiveness. Several new oral anticoagulants (NOACs) have been developed in an attempt to overcome these limitations. Apixaban is a NOAC that selectively inhibits the coagulation factor Xa; it is approved for the prevention of VTE after total hip replacement and total knee replacement surgery. This review examines the results of main trials designed to test efficacy and safety of apixaban in major elective orthopedic surgery.

The use of novel oral anticoagulants for thromboprophylaxis after elective major orthopedic surgery

Venous thromboembolism is a common cause of morbidity and mortality among patients undergoing elective orthopedic surgery. Due to the high incidence of venous thromboembolism in this setting, perioperative anticoagulation is the recommended approach for thromboprophylaxis. Low molecular weight heparin (LMWH), fondaparinux and warfarin are the agents commonly used for thromboprophylaxis. The well-recognized limitations of warfarin and the inconvenience and discomfort associated with the subcutaneous administration of low molecular weight heparin and fondaparinux inspired intense investigation to develop novel oral anticoagulants (NOACs) with more predictable pharmacokinetics, fewer drug interactions and no need for regular laboratory monitoring. Three NOACs have been demonstrated to be effective for thromboprophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in large randomized controlled trials. Here we review the pharmacology of rivaroxaban, dabigatran, and apixaban, summarize the major clinical trials of these agents in thromboprophylaxis after THA and TKA, and discuss the clinical factors to be considered by providers when selecting a NOAC for their patients.

Prevention of venous thromboembolism in acutely ill medical patients after the results of recent trials with the new oral anticoagulants

Venous thromboembolism (VTE) is a common potentially life-threatening complication in acutely ill medical patients; over 70 % of the fatal episodes of pulmonary embolism during hospitalization occur in non-surgical patients. In the absence of thromboprophylaxis, the incidence of venographically detected deep vein thrombosis is about 15 % in medical patients. Several trials and meta-analyses have clearly demonstrated the prophylactic role of unfractionated heparin, low molecular weight heparin and fondaparinux. Although over the past few years the knowledge of epidemiology, clinical features and prophylaxis in medical patients has significantly improved, there remain a number of controversial areas that require further investigation. Newer VTE risk assessment models have been proposed to select high risk hospitalized medical patients, but they still require external validation; scarce data are available to stratify patients to identify their individual bleeding risk. The optimal duration of thromboprophylaxis in medical patients is still a matter of debate; currently, extended prophylaxis after discharge is not recommended, but it may be required for subgroup of patients with persistently high VTE risk and a negligible risk of bleeding. Based on the results of recent studies, the new oral anticoagulants appear to have a very limited role, if any. However, a better risk stratification of patients who have a persistently increased risk of VTE is warranted to improve the risk to benefit profile of any anticoagulant drug to be used in this setting.

[Adherence to and satisfaction with oral outpatient thromboembolism prophylaxis compared to parenteral: SALTO study]

INTRODUCTION

Prolongation of drug-based thromboembolism prophylaxis after discharge from hospital is clearly recommended following total hip and knee replacement. The aim of this study was to evaluate and compare adherence to and satisfaction with outpatient thromboembolism prophylaxis (by injection and oral) under routine clinical practice conditions.

MATERIAL AND METHOD

We analysed two consecutive cohorts of patients (480 and 366, respectively) who had undergone total hip or knee replacement surgery in 120 Spanish hospitals, and were prescribed outpatient thromboembolism prophylaxis, by injection and orally, respectively. Information on adherence to and satisfaction with both treatments, sociodemographic data and treatment compliance was collected using specific questionnaires.

RESULTS

The drop-out rate (9.49 vs. 4.14%), general satisfaction (37 vs. 83.38%), and the TSQM satisfaction scale were better in the oral prophylaxis cohort and, although the differences between the two routes of administration were not significant, treatment compliance was also better in the oral cohort (Morisky-Green test: 53.49 vs. 59.05%).

CONCLUSIONS

Adherence to and satisfaction with the oral thromboembolism prophylaxis were better than for prophylaxis by injection in the context of outpatient prolongation. Nevertheless, suboptimal treatment compliance was found in both cohorts, which could result in lack of efficacy of the prophylaxis. Both patients and doctors have to be made aware of the importance of post-discharge extension of thromboprophylaxis in orthopaedic surgery with high thrombotic risk. Moreover, strategies should be developed to encourage compliance.