Hello Health Rounds readers! Medicines from the same class of drugs prescribed to treat the same condition are not always equal, and today we have a clear example for patients who need to prevent recurring blood clots. We also report on a fascinating discovery of a link between the aging gut and cognitive decline in mice that could one day lead to new treatments for people.

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NATO's biennial drill in the European Arctic is placing more focus on the role of civilians, businesses and public institutions in supporting the military, in case war breaks out and soldiers and civilians need transportation for medical care.

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.

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.”

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 in California 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.”

On Monday, March 16 at Pharma USA 2026 in Philadelphia, Genentech CEO Ashley Magargee and Reuters Global Pharma Editor Michele Gershberg will discuss the sweeping shifts underway in U.S. and global health policy, the growing influence of AI on drug discovery and regulatory pathways, and the next generation of promising treatments poised to reshape medical practice. Register to watch the session for free.