For the past several decades, warfarin has been the go-to anticoagulant drug for doctors, but now new treatments have emerged in the form of direct oral anticoagulants (DOACs.) DOACs are considered more effective and safer than warfarin, especially in relation to serious bleeding episodes. These anticoagulants include apixaban, dabigatran, edoxaban, and rivaroxaban.
Over the next year, NATF will offer readers a closer look at each DOAC in order to empower patients to make informed healthcare decisions. To kick off the DOAC Deep Dive series, here is the scoop on dabigatran:
What is it?
Dabigatran, also known as Pradaxa, is a blood thinning medication that is taken as a pill twice a day, every 12 hours. It is designed to reduce a patient’s risk of experiencing a blood clot-related issues, such as deep vein thrombosis, pulmonary embolism, and stroke from atrial fibrillation (not caused by a heart valve problem). Dabigatran does this by preventing blood clots from forming.
How does it work?
Dabigatran is a direct thrombin inhibitor. This means that it works to block a clotting agent known as thrombin. Dabigatran binds itself to the thrombin molecules, preventing them from initiating the formation of a blood clot.
“When a blood clot forms, one of the main ingredients for it is fibrin. Fibrin forms when it’s converted from its precursor, fibrinogen. Another entity called thrombin needs to be activated for the conversion to take place.” explained Dr. Azhar Ahmad, the executive director of clinical development and medical affairs at Boehringer Ingelheim. “Pradaxa inhibits what the thrombin is doing. This stops the fibrinogen from forming fibrin and prevents the blood from clotting.”
What sets dabigatran apart from the other DOACs?
Many doctors and patients shy away from the DOACs because, unlike warfarin, they lack reversal agents. However, Boehringer Ingelheim, the makers of dabigatran, have set their drug apart by creating a reversal agent known as idarucizumab. It is also referred to as Praxbind.
“It is an antibody specific only to dabigatran and reverses the anticoagulant effect of dabigatran within minutes and has no apparent side effects,” explained Dr. Christian Ruff, who works in the cardiovascular division of Brigham and Women’s Hospital
Idarucizumab was developed to be given as a one-dose-only medication. The drug quickly binds to and neutralizes the dabigatran in a patient’s body. This can be important during emergency situations, such as if a patient experiences a life-threatening bleed or needs emergency surgery.
According to Dr. Ahmad, the use of idarucizumab is very limited because the risk of life-threatening bleeding or needing emergency surgery is low.
Another key benefit of dabigatran, the first anticoagulant on the market after warfarin, is that it prevents ischemic stroke better than both warfarin.
“We are the only one that is superior to warfarin in preventing ischemic stroke,” said Dr. Ahmad. “That was a really key finding. It’s an achievement we’re really proud of.”
What are the risks?
As with any medication, dabigatran does come with its risks. Patients on dabigatran may experience a higher risk of bleeding. This is especially true of patients that are over the age of 75 years old, have kidney problems, or that have had recent stomach or intestinal bleeding, including stomach ulcers. Because of this risk, patients on dabigatran should always talk to a doctor before receiving any type of surgery, medical procedure, or dental procedure. Dabigatran may also cause patients to bruise more easily.
What are the benefits?
Dabigatran has been shown to be an effective and safe alternative to warfarin. In the RE-LY® trial, dabigatran was shown to significantly reduce the risk of stroke in non-valvular atrial fibrillation patients compared with warfarin. Real-world studies have provided further data comparing dabigatran and warfarin and other DOACs. In 2009, the RE-COVER study compared dabigatran to warfarin based on how well the drugs treated acute venous thromboembolism (VTE). The randomized, double-blind noninferiority trial showed that dabigatran was just as effective as warfarin in treating VTE. Then in 2013, researchers followed up on the study with the RE-COVER II study and determined that dabigatran had a lower risk of bleeding than warfarin for the treatment of VTE.
It’s important that patients always consult with their doctor before starting or stopping dabigatran. Only an individual doctor can decide what treatment will work best for an individual patient.
“We encourage everyone to discuss their treatment options with their doctors. I think now that there is more than one anticoagulant available, patients can receive some information overload,” explained Dr. Ahmad. “It is a really important life-long decision; we feel very strongly that a patient-physician dialog needs to occur.”
Boehringer Ingelheim is a sponsor of NATF. They had no influence over the content of this article beyond providing non-biased scientific information about dabigatran.