New oral anticoagulants
New oral anticoagulants (NOACs) are a class of medications that are used to prevent stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF). They are also used to treat deep vein thrombosis (DVT) and pulmonary embolism (PE). NOACs are an alternative to warfarin, a traditional oral anticoagulant, and have several advantages over warfarin.
Here are some key features and benefits of NOACs:
Mechanism of Action:
NOACs work by inhibiting the activity of factor Xa, a clotting factor that is involved in the formation of blood clots. They do not require regular blood monitoring, unlike warfarin, which requires regular monitoring of the international normalized ratio (INR) to ensure that the blood is not too thin or too thick.
Types of NOACs:
There are several types of NOACs, including:
- Dabigatran (Pradaxa): approved in 2010 for the prevention of stroke and systemic embolism in patients with non-valvular AF.
- Rivaroxaban (Xarelto): approved in 2011 for the prevention of stroke and systemic embolism in patients with non-valvular AF, as well as for the treatment of DVT and PE.
- Apixaban (Eliquis): approved in 2012 for the prevention of stroke and systemic embolism in patients with non-valvular AF, as well as for the treatment of DVT and PE.
- Edoxaban (Savaysa): approved in 2015 for the prevention of stroke and systemic embolism in patients with non-valvular AF, as well as for the treatment of DVT and PE.
- Betrixaban (Bevyxxa): approved in 2017 for the prevention of venous thromboembolism (VTE) in patients undergoing hip or knee replacement surgery.
Benefits:
NOACs have several benefits over warfarin, including:
- Convenience: NOACs do not require regular blood monitoring, which can be a significant advantage for patients who have difficulty adhering to a strict medication regimen.
- Fewer interactions: NOACs have fewer interactions with other medications than warfarin, which can reduce the risk of adverse effects.
- Fewer bleeding complications: NOACs have been shown to have a lower risk of bleeding complications than warfarin, particularly in patients with a history of bleeding.
- Improved patient outcomes: NOACs have been shown to improve patient outcomes, including reducing the risk of stroke and systemic embolism.
Side Effects:
NOACs can cause side effects, including:
- Gastrointestinal symptoms: nausea, vomiting, diarrhea
- Headache: headache, dizziness
- Fatigue: fatigue, weakness
- Bleeding: bleeding, including gastrointestinal bleeding and intracranial hemorrhage
Contraindications:
NOACs are contraindicated in patients with:
- Severe renal impairment: patients with severe renal impairment may have an increased risk of bleeding complications.
- Severe liver impairment: patients with severe liver impairment may have an increased risk of bleeding complications.
- Active bleeding: patients with active bleeding may be at increased risk of bleeding complications.
- Recent surgery: patients who have recently undergone surgery may be at increased risk of bleeding complications.
Dosing:
The dosing of NOACs varies depending on the specific medication and the indication for use. For example:
- Dabigatran: 150 mg twice daily for the prevention of stroke and systemic embolism in patients with non-valvular AF.
- Rivaroxaban: 20 mg once daily for the prevention of stroke and systemic embolism in patients with non-valvular AF.
- Apixaban: 5 mg twice daily for the prevention of stroke and systemic embolism in patients with non-valvular AF.
- Edoxaban: 60 mg once daily for the prevention of stroke and systemic embolism in patients with non-valvular AF.
Monitoring:
NOACs do not require regular blood monitoring, unlike warfarin. However, patients taking NOACs should be monitored for signs of bleeding or other adverse effects.
Conclusion:
NOACs are a class of medications that are used to prevent stroke and systemic embolism in patients with non-valvular AF, as well as to treat DVT and PE. They have several advantages over warfarin, including convenience, fewer interactions, and fewer bleeding complications. However, NOACs can cause side effects and are contraindicated in certain patients. The dosing of NOACs varies depending on the specific medication and indication for use, and patients taking NOACs should be monitored for signs of bleeding or other adverse effects.