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Published on: February 28, 2012
Unresolved issues in the use of direct acting oral anticoagulants
1Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Introduction:
Currently approved direct oral anticoagulants (DOACs) target thrombin or coagulation factor Xa. Administered in fixed doses without routine laboratory monitoring, DOACs have simplified the approach to oral anticoagulation, when previously the choice was limited to vitamin K antagonists (VKAs).
Area Covered:
We discuss a) unresolved issues related to optimal use of DOACs and b) new developments including the potential for FXIa inhibitors to be effective and safer anticoagulants.
Expert Opinion:
By simplifying oral anticoagulation, DOACs have facilitated the uptake of anticoagulation. The DOACs are approved for stroke prevention in atrial fibrillation and for the prevention and treatment of venous thromboembolism, and their indications are expanding to include the prevention of atherothrombosis. DOACs have now replaced vitamin K antagonists (VKAs) for most indications, but not all. DOACs are inferior to VKAs for patients with mechanical heart valves, left ventricular assist device, rheumatic atrial fibrillation, and those with antiphospholipid syndrome, and their safety and efficacy are uncertain in some populations (e.g. advanced renal and liver disease). Impediments to use include concerns for bleeding and cost. The newly developed FXIa and FXIIa inhibitors have the potential to be safer than current anticoagulants, but phase 3 trials are needed to confirm their clinical efficacy and safety.
Insights
Direct oral anticoagulants (DOACs) simplify anticoagulation but have limitations. Emerging factor XIa inhibitors may offer safer alternatives, pending further clinical trials for efficacy and safety.
Area of Science:
- Pharmacology
- Cardiovascular Medicine
- Hematology
Background:
- Direct oral anticoagulants (DOACs) targeting thrombin or factor Xa have simplified anticoagulation therapy.
- DOACs are administered in fixed doses without routine monitoring, unlike traditional vitamin K antagonists (VKAs).
Purpose of the Study:
- To discuss unresolved issues in the optimal use of current DOACs.
- To explore new anticoagulant developments, focusing on factor XIa (FXIa) inhibitors as potentially safer alternatives.
Main Methods:
- Review of current literature on DOACs and emerging anticoagulants.
- Analysis of clinical applications, limitations, and safety profiles of anticoagulation therapies.
Main Results:
- DOACs have expanded anticoagulation use but are not suitable for all patients (e.g., mechanical heart valves, antiphospholipid syndrome).
- Concerns regarding bleeding and cost remain impediments to DOAC use.
- FXIa inhibitors show potential for improved safety, but large-scale trials are necessary.
Conclusions:
- While DOACs have revolutionized anticoagulation, specific patient populations require alternative therapies.
- FXIa inhibitors represent a promising next generation of anticoagulants, pending robust clinical validation.
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