Anticoagulants like Pradaxa have been popular choices for atrial fibrillation patients who need to reduce their risk of clot-related complications, but the same drug that prevents complications like stroke may make other conditions such cerebral hemorrhages more dangerous.

Pradaxa, known generically as dabigatran, was first approved for sale by the Food and Drug Administration (FDA) in 2010. It’s widely used to prevent stroke and systolic embolism in patients with non-valvular atrial fibrillation. The FDA has also approved it to treat and prevent pulmonary embolism and deep venous thrombosis.

Patients with atrial fibrillation are at risk for dangerous conditions like stroke that can result from clots within the blood. When the heart can’t adequately move the blood it’s supposed to, some blood pools inside the heart, and that stagnation of blood may allow clots to form.

Pradaxa works by inhibiting the action of a naturally-occurring clotting enzyme known as thrombin. Reducing the blood’s ability to clot decreases the likelihood of conditions like stroke. But the flip side of that coin is that if the patient starts bleeding, their body’s own clotting mechanism will be less able to stop the bleeding, putting the patient at risk for dangerous blood loss.

Cerebral hemorrhage is one type of bleeding that Pradaxa can complicate. Cerebral hemorrhage occurs when a blood vessel in or around the brain breaks, causing bleeding inside or around the brain.

Cerebral hemorrhage symptoms can vary widely. They can sometimes resemble symptoms of a stroke — symptoms like weakness on one side of the body, difficulty speaking, or numbness can all be cerebral hemorrhage symptoms. In fact, cerebral hemorrhage can lead to stroke: about 10 percent of strokes are caused by bleeding in the brain.

Other cerebral hemorrhage symptoms can include headache, vision abnormalities, impairment of balance or coordination, and sudden seizures.

Cerebral hemorrhage treatment also varies, depending on the specifics of the situation. The first priority is to stabilize the patient’s blood pressure. To address the bleeding itself, the patient may need emergency surgery. Cerebral hemorrhage symptoms like pain, blood pressure, or seizure may have to be addressed with medication.

After the initial cerebral hemorrhage treatment, the patient may still need long-term rehabilitation to cope with lasting residuals. Some patients may need ongoing speech, physical or occupational therapy. Others may simply have to live with persistent headaches, cognitive problems, or loss of motor function.

Cerebral Hemorrhage and Pradaxa

Cerebral hemorrhage has been particularly dangerous with Pradaxa due to the lack of an antidote for its anticoagulant effect. Unlike with the older anticoagulant warfarin, whose effect can be reversed by administering vitamin K, there was no known antidote for Pradaxa when it was originally approved. Pradaxa was on the market for years before the FDA finally approved an antidote in October 2015.

Thousands of patients who needed cerebral hemorrhage treatment or suffered other types of Pradaxa bleeding have brought legal claims against the drug’s manufacturer Boehringer Ingelheim Pharmaceuticals. Plaintiffs in these Pradaxa lawsuits claimed the company had failed to provide proper dosing information and had misrepresented Pradaxa’s safety and effectiveness.

In May 2014, Boehringer Ingelheim agreed to settle 4,000 of these claims to the tune of $650 million.