Jantoven, Marevan and Waran might sound like the name of a law firm, but it’s actually a list of some of the lesser-known brand names for the anticoagulation drug, “warfarin.”
The most widely known brand name for this medication is Coumadin – which is the world’s most frequently prescribed drug for the treatment of atrial fibrillation and stroke prevention.
Coumadin is very widely used in Indian River County, according to Nikki Daubar, doctor of pharmacology and medication management clinic coordinator at Indian River Medical Center.
Daubar says upwards of 1,500 patients come into the IRMC Coumadin clinic every two to four weeks for tests and adjustments. “Someone who’s brand new [to the medication] might even come see us every couple of days to begin with,” she adds.
As temperatures drop up north and snowbirds return to Vero the number patients and visits rise. “I took about 25 phone calls today,” says Daubar, “from people who are back in town [for the winter] and need an appointment.”
Patients come in so frequently because Coumadin requires careful and constant monitoring to prevent potentially fatal side effects.
The origins of the drug help explain its dangers.
Back in 1940 scientists at the University of Wisconsin discovered a natural anticoagulant in sweet clover that led to local cattle bleeding to death from small cuts and scratches on their legs. The name warfarin came from WARF or Wisconsin Alumni Research Foundation. Originally used as a rodenticide, a modified version is now a top-selling human life-saver.
While often referred to as a “blood thinner,” warfarin does not actually thin the blood at all. Instead, according to the American Heart Association, it makes blood slower to coagulate or clot.
The U.S. National Library of Medicine at the National Institutes of Health says that upwards of 20 million Americans are currently taking warfarin and another 2 million start using the drug each year. It also bluntly states that, “Getting the dose just right is a tricky business involving frequent office visits for blood tests and dosage adjustments.”
Being on warfarin without these blood tests and dosage adjustments can be something of a damned-if-you-do and damned-if-you-don’t situation. Again, the U.S. National Library of Medicine is quite candid. “Too much warfarin,” it says, “and you can bleed to death. Too little and a blood clot may get you.”
According to Daubar, “The majority of our [warfarin] patients have atrial fibrillation, which is an irregular heartbeat. What that does is it puts people at a very increased risk of developing a stroke. Many of them might have had one before so what we’re trying to do is prevent that from happening [again].”
Administered in the correct dosage, warfarin helps keep blood clots from forming and causing strokes, heart attacks, deep vein thrombosis and/or pulmonary embolisms.
That said, warfarin also decreases the body’s ability to stop bleeding from cuts, falls and similar traumas. As the American Heart Association points out, warfarin blocks the body’s vitamin K-dependent clotting factors which normally prevent excessive bleeding.
It is precisely for that reason that warfarin ranks third on the long list of FDA-approved pharmaceuticals in causing “adverse effects” that require hospitalization.
In July of this year, ProPublica reported that, “From 2011 to 2014, at least 165 nursing home residents were hospitalized or died after errors involving Coumadin or its generic version, warfarin,” and added, “Studies suggest there are thousands more injuries every year that are never investigated.”
That makes continuous monitoring of warfarin all the more important.
“What we do here,” explains Daubar, “is we bring patients in and check their levels by using just a finger stick. We get the readings within about 30 seconds. We then can see if their medication is working appropriately; if they have too high of a dose or too low of a dose, we can make the dosage adjustments we need to.”
There are other, newer, non-warfarin anti-coagulants available that do not require such frequent testing but, according to Daubar, they have problems of their own.
Eliquis, Cardoxin and Xarelto, for example, don’t require monitoring but Daubar says, “None of those medications have any reversal agents.”
That is, if the patient is in a car accident or has a fall and is bleeding, there’s nothing that can reverse the effects of those newer anticoagulants.
With warfarin, on the other hand, Daubar says, “we can immediately give Vitamin K, fresh frozen plasma and different things like that that will reverse the effects of the warfarin.”
Of course, decisions about which medication is best for each patient should be made by that patient and his or her physician.
In the meantime, however, IRMC was just recognized this October as an “anticoagulation center of excellence” by the Anticoagulation Forum and has a long history in caring for patients using Coumadin or other forms of warfarin
Nikki Daubar is at the Indian River Medical Center’s Coumadin clinic in hospital’s ambulatory care center. The phone number is 772-567-4311.