Aspirin outperformed by new clot busting drug

Washington: Turns out, the blood thinner rivaroxaban is as safe as aspirin and more effective clot-buster.

Venous thromboembolism is a chronic disease, with risks of additional blood clots over a patient's lifetime.

However, many physicians and patients are deciding against long-term treatment with blood thinners because of concern about the risk of bleeding. Some are choosing aspirin instead because they consider it to be safer.

The large international study of 3,396 patients with venous thromboembolism in 31 countries shows, however, that rivaroxaban is more effective than aspirin.

"Not only that, but in testing two doses of rivaroxaban, we found that we have the option of lowering the daily dose for extended treatment," said principal investigator Jeffrey Weitz from the McMaster University. "This will ease the long-term concerns of both patients and their doctors."

During the study from March 2014 to March 2016, patients received either a daily 20mg dose of rivaroxaban, a 10mg dose of rivaroxaban, or a 100 mg dose of aspirin. They took these medications for up to 12 months after they had received treatment for their initial clot.

The researchers found that patients taking aspirin had the highest rate of recurrent blood clots, at 4.4 percent. The rates of recurrent clots for patients taking 20mg and 10mg of rivaroxaban were significantly lower, at 1.5 and 1.2 percent respectively.

When they looked at bleeding side-effects, there were no statistically significant differences between the treatments. The rates of major bleeding were 0.3 percent in the group taking aspirin, and 0.5 percent and a 0.4 percent in the groups taking 20 mg and 10mg of rivaroxaban, respectively. The study is published in the New England Journal of Medicine.