Traditionally, anticoagulants have been used to treat venous thromboembolism and prevent stroke in patients with atrial fibrillation. However, the consequences with other medications, food or alcohol have led to the emergence of the new oral anticoagulants or NACOS.
What are the new oral anticoagulants and what are their uses?
The new oral anticoagulants, better known as NACOS, are a controversial subject even among specialists in hematology and anticoagulation.
For many years, oral anticoagulants in the prevention and treatment of venous thromboembolism have been carried out thanks to vitamin K antagonist drugs (VKA). This type of drug has also been used for the prevention of stroke in patients with atrial fibrillation (the most frequent type of arrhythmia), in the prevention of thromboembolism in patients with mechanical heart valves, and for other indications. In fact, it is estimated that, in Spain, 14 out of every 1000 inhabitants receive this type of treatment per year.
According to hematology experts, this type of therapy requires strict control to achieve reasonable levels of safety in anticoagulation, since interaction with other types of drugs or even food or alcohol has consequences. However, and because of this, research has been carried out into the appearance of new molecules with a greater therapeutic margin and little variability between patients and within the same patient. This would allow the administration of a fixed dose without the need for such close monitoring of the patient.
For these reasons, drugs called NACOS appeared, which have a specific target on the blood coagulation cascade; specifically, on factors II (thrombin) and coagulation factor X, which makes their anticoagulant action more physiological.
Why the new anticoagulants or NACOS have not displaced the conventional ones
Although these drugs will undoubtedly be the future of anticoagulant therapy, more randomized clinical trials are still needed to establish the correct indication for them.
Specialists have doubts as to how and when analytical control of anticoagulated patients should be performed, especially in situations of thrombotic or hemorrhagic risk:
– invasive procedures or surgery
– neuroaxial anesthesia
– thrombolysis in case of stroke or infarction
In addition, these NACOS are susceptible to pharmacokinetic interactions with certain types of antibiotics, anticonvulsants or antiarrhythmics, and have a variable degree of renal elimination ranging from 80% to 20%. This could increase the risk of hemorrhagic phenomena in patients with renal insufficiency.
The lack of a completely effective treatment generates some uncertainty, especially due to the lack of experience in the treatment of possible hemorrhagic complications.