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Newest blood-thinning drugs are the subject of a troubling, in-depth series on their safety

2015 Xarelto commercial featuring Arnold Palmer, Kevin Nealon and Brian Vickers.

In a series of investigative articles published jointly this week in the Milwaukee Journal Sentinel and MedPage Today, reporters John Fauber and Coulter Jones offer a troubling, in-depth look at the safety record of the much-touted (and advertised) blood-thinning drugs known as novel oral anticoagulants (NOACS).

Anticoagulant drugs are used to treat several heart conditions, most notably atrial fibrillation (a risk factor for stroke). They’re also used to prevent or treat blood clots.

NOACS — which include Xarelto (rivaroxaban), Eliquis (apixaban), Pradaxa (dabigatran) and Savaysa (edoxaban) — have been on the market in the U.S. since 2010.  They claim to be more convenient for patients than warfarin, the generic name for a blood-thinner that has been in use since the 1950s.

Patients taking a NOAC, unlike those on warfarin, do not have to undergo regular blood tests to make sure the drug is working properly. Nor do they have to restrict their diets to avoid too much alcohol and certain foods (like spinach and kale) that can weaken the effectiveness of warfarin.

A serious side effect

But, as Fauber and Jones point out, NOACS have another characteristic that too often gets underplayed.

“Unlike warfarin, which is a vitamin K antagonist that can be turned off in a bleeding emergency or prior to surgery by administering vitamin K, all of the NOACs were approved without an antidote, although packed red blood cells can slow their anticoagulation action,” they write.

The consequences of this lack of an antidote can be grave, as Fauber and Jones report:

Since 2010, more than 58,000 people have reported a serious side effect, such as a major bleeding episode, after using one of the anticoagulants designed to replace warfarin. … 

At least 8,000 deaths have been linked to three of the new anticoagulant drugs since 2010, compared with about 700 for warfarin. Mortality data for the fourth drug [Savaysa], approved in January, is not yet available.

These numbers are drawn from the FDA’s adverse events reporting system, which is largely voluntary. Though the reports are not verified, the numbers suggest an imbalance: the three newer drugs accounted for less than 10% of all anticoagulant prescriptions, yet they were linked to more than 90% of deaths reported to the FDA since 2010.

Billions at stake

Yet the sales of NOACS are booming. “More than 10 million prescriptions for the new drugs, costing about $3.5 billion, were dispensed in 2014, according to data from IMS Health, a market research firm,” write Fauber and Jones. “Prescriptions for warfarin, which is a fraction of the price, went down slightly in 2014 compared with 2013 and 2012.”

The switch to the newer anticoagulants is costing all of us money, whether we’re taking the drugs or not.

“In 2013, taxpayers paid more than $1 billion for prescriptions of just two of the drugs, Xarelto and Pradaxa (dabigatran), according to an analysis of Medicare data., write Fauber and Jones. “Warfarin was dispensed about six times more often, but cost taxpayers significantly less — $240 million.”

A question of scale

The surge in sales of NOACS has been bolstered, Fauber and Jones point out, “by a new system for determining stroke risk that was devised by a British doctor who, the MedPage Today/Journal Sentinel investigation found, has extensive financial ties to companies that make or market the new drugs.”

“The new system was adopted as part of treatment guidelines by leading medical societies in the U.S. and Europe — ones that themselves have received millions from drug manufacturers,” they add. “In addition, many of the doctors who wrote those guidelines or issued other recommendations had personal financial ties to those companies, such as working as speakers or consultants.”

Under the new scale, “the number of Americans deemed in need of an anticoagulant jumped overnight from an estimated 3.7 million to 4.7 million, according to a paper published in May in the journal JAMA Internal Medicine,” Fauber and Jones report.

“That number includes nearly all women with atrial fibrillation, and virtually everyone 65 or older with the condition are considered candidates for being on the drug,” they add.

‘More harm than good’

Dr. Rita Redberg, a cardiologist at the University of California, San Francisco, and editor of JAMA Internal Medicine, told Fauber and Jones that she advises patients to wait a few more years before using the NOACS — “until the true risks and benefits of the new drugs are known.”

“I don’t prescribe any of the newer oral anticoagulants,” she said. “My concern is that a lot of the people being put on the novel oral anticoagulants will have more harm than good.”

You can read the Fauber and Jones’ series of articles on either the Milwaukee Journal or MedPage websites.

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