Blood Thinners May Face Increased Bleeding Risks During Respiratory Tract Infections: Study

The findings raise concerns over how healthcare professionals should mitigate the bleeding risks when infections are diagnosed, the researchers warn.

Taking commonly used blood thinners like warfarin, Pradaxa, Xarelto and Eliquis while suffering from a respiratory tract infection could increase the risk of bleeding events, according to the findings of a new study.

Researchers from the U.K. indicate that patients taking direct oral anticoagulants faced more than double the risk of major and non-fatal bleeding events when they contracted respiratory infections, and called for more research into how this risk might be mitigated in the future. Their findings were published on December 21 in The BMJ.

Direct oral anticoagulants are often prescribed to prevent strokes in patients with atrial fibrillation, but are also often prescribed for other blood-thinning purposes. They include the older vitamin k antagonist, warfarin, as well as newer blood thinners such as Pradaxa, Xarelto and Eliquis.

All of these drugs have been linked to increased bleeding risks, which can sometimes be fatal. Warfarin has been the go-to blood thinner for decades, and bleeding events can be treated with vitamin k-based reversal agents. Pradaxa, Xarelto and Eliquis are all part of a new generation of anticoagulants, but were also linked to severe and uncontrollable bleeding problems, especially before reversal agents were introduced in 2018.

In this latest study, researchers looked at data on 1,208 adult users of warfarin or other direct oral anticoagulants. The other drugs were not listed by name.

The researchers looked at general practice or hospital admission records involving a bleeding event between January 2010 and December 2019, as well as records of consultations for community acquired respiratory tract infections which were untreated by antibiotics.

According to their findings, the relative incidence of major bleeding was 2.68 times as high for blood thinner users within two weeks of a respiratory tract infection diagnosis than for those without. The risk of non-major bleeding events was 2.32 times as high. The researchers noted the findings did not vary between the types of blood thinner being used nor by gender.

“This study observed a greater than twofold increase in the risk of bleeding during the 0-14 days after an untreated respiratory tract infection,” the researchers concluded. “These findings have potential implications for how patients and clinicians manage oral anticoagulant use during an acute intercurrent illness and warrant further investigation into the potential risks and how they might be mitigated.”

Incidents of unstoppable bleeding have resulted in thousands of reports involving injury or death for patients using the new drugs. About 30,000 Xarelto lawsuits were filed against the drug makers, alleging that users and the medical community were not adequately warned about the risk of problems linked to the drug and lack of an effective reversal agent when it was first introduced.

Following a handful of early bellwether trials, which were held before U.S. District Judge Eldon Fallon in the Eastern District of Louisiana to help gauge how juries may respond to certain evidence and testimony that was likely to be repeated throughout the litigation, a global Xarelto settlement was reached in March 2019, resolving nearly all claims.