Newer Blood Thinners May Not Bring Higher Bleeding Risk
Many patients who suffer from blood clots in their legs -- called venous thromboembolism (VTE) -- or have the abnormal heart rhythm called atrial fibrillation take blood thinners to help prevent life-threatening clots that can travel to the heart, lung or brain.
"Given the advantages associated with these new drugs not requiring frequent monitoring, our results suggest that they may be considered as a treatment option for patients with VTE who are candidates for receiving oral anticoagulant therapy," said lead researcher Min Jun. He is a senior research fellow at the University of New South Wales in Sydney, Australia.
Jun cautioned, however, that the Canadian-Australian study was an observational one, so the possibility that results were due to other unmeasured factors cannot be excluded.
The standard anti-clotting drug is warfarin. Although the drug is effective, it has to be closely monitored with frequent blood tests to ensure it provides protection without the risk of major bleeding.
Newer anticoagulants, called direct oral anticoagulants, are as effective as warfarin and don't require constant blood tests. But whether they increase the risk for major bleeding has not been clear from clinical practice. That's important because only Pradaxa has an antidote that can stop bleeding should it occur.
According to Dr. Byron Lee, "The direct oral anticoagulants have been getting a lot of bad press." Lee is director of electrophysiology laboratories and clinics at the University of California, San Francisco.
"Late-night TV commercials about class-action lawsuits scare patients into believing these new drugs are dangerous," he said.
The reality, Lee added, is that studies have shown that these new drugs are just as safe as warfarin, if not better.
"Some of these drugs do not yet have a reversal agent, yet this study showed that in a real-world setting, these drugs are not leading to more major bleeds or deaths," Lee said.
The one downside to these drugs is that they are often more expensive than warfarin, with higher co-pays, depending on the insurance plan.
To see how these drugs performed, Jun and his colleagues identified nearly 60,000 patients in the United States and Canada who had been diagnosed with VTE and were prescribed warfarin or one of the newer drugs between January 2009 and March 2016.
Over an average of 85 days of follow-up, slightly more than 3 percent of the patients had an episode of major bleeding and nearly 2 percent died.
The risk of major bleeding was similar for both the newer anticoagulants and warfarin, the researchers found. And there was no difference in the risk of death, Jun said.
These findings didn't change when patients were followed for up to six months, he added.
However, Jun noted, "Further studies are needed to better understand the longer-term safety of these drugs among VTE patients as well as their safety among advanced chronic kidney disease patients, in whom the risk of major bleeding is greater compared with other patient groups."
The report was published online Oct. 17 in BMJ.
For more on anti-clotting drugs, visit the American Heart Association.
Posted: October 2017
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