March 13 (Reuters) - A trial directly comparing Eliquis and Xarelto - two commonly used blood-thinning drugs from the same class of medicines - found that Eliquis carries a clearly lower risk of dangerous bleeding in patients with clots deep in the body, researchers reported in The New England Journal of Medicine.
A pharmacist holds a bottle of the drug Eliquis, made by Pfizer Pharmaceuticals, at a pharmacy in Provo
Eliquis, known chemically as apixaban, is sold by Bristol Myers Squibb and Pfizer, while Xarelto (rivaroxaban) is sold by Bayer and Johnson & Johnson.
The drugs, given to prevent recurrent blood clots that can lead to strokes, can sometimes also cause serious bleeding episodes.
"This trial provides highly anticipated evidence for physicians and should bring real peace of mind to venous thrombosis patients, who often live with the dual fear of blood clot recurrence and bleeding," study leader Dr. Lana Castellucci of The Ottawa Hospital in Canada said in a statement.
The researchers enrolled 2,760 patients with a venous thrombosis - blood clots in the veins - in the legs or lungs and randomly assigned them to treatment with one of the two anticoagulants.
After three months – the standard course of treatment - 7.1% of participants taking Xarelto had experienced clinically relevant bleeding, compared to 3.3% of participants who received Eliquis.
There did not appear to be a difference in the risk of recurrent blood clots, suggesting both drugs work for their intended purpose, although there weren't enough study participants to allow reliable detection of a true effect, researchers said.
The study involved mainly white patients with healthy kidneys and livers and without cancer or obesity, so the results may not be applicable to everyone, the researchers acknowledged.
"Despite these limitations, the trial provides vital evidence for the treatment of venous thromboembolism," Dr. Lisa Moores of the Uniformed Services University of the Health Sciences in Bethesda, Maryland, wrote in an NEJM editorial. "Apixaban is a safer first-line option than rivaroxaban for minimizing the risk of bleeding without compromising the prevention of recurrent thrombosis."
THE AGING GUT CAN IMPAIR THE AGING BRAIN
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Changes in the intestines with aging can contribute to cognitive declines, a study in mice suggests.
The aging gastrointestinal tract produces molecules that blunt the activity of the vagus nerve, a key pathway for communication between the gut and the brain, researchers reported in Nature.
In particular, a microbe called Parabacteroides goldsteinii, which produces molecules called medium-chain fatty acids, or MCFAs, becomes more abundant with age.
High levels of MCFAs activate immune cells in the gut to produce inflammatory signaling molecules. One of these, IL-1beta, impairs the function of the vagus nerve, which plays a critical role in communication between the intestines and the hippocampus of the brain, where memories are formed.
In mice with cognitive decline, administering a bacterial virus that inhibits the activity of P. goldsteinii resulted in lower MCFA levels and improved memory, the researchers found.
Furthermore, stimulating the vagus nerve by administering either the hormone cholecystokinin that regulates digestion, or the GLP-1 drug Saxenda from Novo Nordisk, reversed age-related memory deficits in the mice, they also found.
"The degree of reversibility of age-related cognitive decline in the animals just by altering gut-brain communication was a surprise," study leader Christoph Thaiss of Stanford Medicine said in a statement.
"We tend to think of memory decline as a brain-intrinsic process. But this study indicates that we can enhance memory formation and brain activity by changing the composition of the gastrointestinal tract — a kind of remote control for the brain."
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(Reporting by Nancy Lapid; Editing by Bill Berkrot)
