A love-hate relationship for Coumadin (warfarin) is playing out online, say authors of a new report that may offer lessons for marketers of new blood-thinning products.
Among blog posts and user forums appearing from May 1999 to September 2010, the authors found 1,223 mentions of either the brand name Coumadin or generic name warfarin, making it the most talked about anticoagulant by patients and physicians. That's not surprising considering that the 60-year-old drug is the most commonly used oral blood thinner in the US.
While warfarin may be the standard of care, determining whether to put patients on it is anything but.
“You would think, theoretically, that after  years, people would understand anticoagulation therapy,” said Michele Bennett, COO of Wool Labs, which issued the report
, a follow-up to its analysis showing how social media gave an early warning on Avandia safety issues
. “There's still a lot of disagreement between patients and physicians about how to treat and when, and whether to keep patients on it for life.”
A 2009 conversation on Medscape involving a 45-year-old male, who comes to the ER suspecting a deep vein thrombosis or pulmonary embolism, goes on for 45 posts, featuring differing views from hematologists, PCPs and an emergency room physician on what tests to order to determine whether to anticoagulate.
“This just shows me that there is dramatic confusion and disagreement about this issue,” wrote one poster, a family doctor trying to decide whether to allow his daughter to go on long-term warfarin therapy.
Management issues don't help. The drug requires frequent blood tests and dosage adjustments to prevent excessive bleeding, and this can become cumbersome for doctor and patient alike. These issues have prompted many patients to question the wisdom of lifelong treatment, and sentiment is low.
The angst surrounding warfarin is the main reason pharmaceutical companies have been working to come up with a replacement that doesn't require coagulation testing. Now there is one: New blood thinner Pradaxa (dabigatran) was approved this month and is being launched in coming weeks by Boehringer Ingelheim. A second product being developed to replace warfarin is Xarelto (rivaroxaban); Johnson & Johnson and Bayer filed an NDA in 2008, and the FDA has yet to allow it on the market.
Neither new drug requires blood monitoring. So, will it be smooth sailing for these new entrants? Not likely, as each has had side effects. In a Pradaxa phase III
study, a very small but statistically significant increase in the risk
of heart attack was seen. For Xarelto, potential liver issues surfaced
during late-stage testing.
Because physicians may have to worry about these other safety issues, the lack of blood monitoring is no guarantee of acceptance among HCPs. "We're not seeing evidence in social media that there will be really fast uptake," said Bennett. "I see comments from physicians saying, 'I'll wait and see.'" The potential side effects may defuse the testing issue. “The nice thing about Coumadin is there is no need to monitor other parts of the body when you take it.”
On the patient side, some do talk about the active coagulation testing, called INR monitoring, but many also make no mention of it at all. Many have no issues with warfarin except when faced with the prospect of lifelong treatment. They have largely ignored warfarin's adverse interactions to other drugs, including antiplatelet drug Plavix (clopidogrel) from Bristol-Myers Squibb/Sanofi-Aventis.
A bigger concern on the patient side is warfarin's food interactions, and this may be where the rubber meets the road for Pradaxa and Xarelto. Patients are advised to keep vitamin K intake consistent week to week by watching their intake of foods high in the vitamin, such as green, leafy vegetables. “Patients don't talk about getting tested as much as they should, and
food interactions are well-discussed and well-known to patients," Bennett noted. Manufacturers of the new products say treatment with Pradaxa has no recommended dietary restrictions, while Xarelto has "limited potential" for food and drug interactions.
The newcomers will no doubt face skeptical managed care organizations reluctant to put a more expensive drug on formulary alongside relatively cheap warfarin therapy. "[Manufacturers] definitely need to talk about how to differentiate themselves from Coumadin in a way that says the cost and effort to figure it out is worth it," Bennett advised.
Right now, she said, neither Pradaxa nor Xarelto have inspired a groundswell of anticipation online. Their heart and liver issues are not well known. That means marketers have a chance to educate on ways patients can manage the risks as they build product awareness.
While some may say the devil they know is better than the one they
don't, time will tell whether patients and doctors may be willing to trade warfarin's
well-known issues for the relatively less understood risks of a new
And, Bennett cautions, those small safety signals are not to be ignored. As with Avandia, where an increase in heart attacks among a small population eventually led to the product nearly getting pulled from the US market: "The eyes and ears of the few become the voice of the many."