Makers of the anticoagulant, Pradaxa, have added the most serious warning, a black box warning, to the prescribing information to alert consumers about the additional risk of stroke when a patient stops taking the drug.
Pradaxa (dabigatran) is a blood thinner prescribed to patients to treat the risk of a blood clot or stroke resulting from non-valvular atrial fibrillation.
Included in the changes – patients who stop taking Pradaxa without continuing some anticoagulation protocol increase the risk of stroke.
The Pradaxa label also now reflects the postmarket data collected which includes the risk of low platelet count, known as thrombocytopenia, among users of Pradaxa.
The website, Adverse Events, which monitors complications collected by the U.S. Food and Drug Administration’s FAERS (FDA Adverse Event Reporting System), identified 19,359 serious complications including 18,509 which listed Pradaxa as the suspected cause. Adverse events included hemorrhaging, dyspepsia (abdominal pain, impaired digestion) and gastrointestinal hemorrhaging.
The data ranged from November 1997 (pre-Pradaxa approval) to August 2012 and included 6,879 hospitalization and 2,081 deaths. Among those, Pradaxa was named as the suspected and primary cause. That is four-times the previously reported 500 deaths attributed to Pradaxa, a drug that has been on the market a relatively short period of time.
The FDA approved Pradaxa in October 2010 after results from the RE-LY (Randomized Evaluation of Long-term Anticoagulation Therapy) trial of more than 18-thousand patients. It allegedly showed dabigatran had equal bleeding risks to warfarin with lower rates of stroke.
However, we’ve reported many times that Pradaxa has no antidote therefore there is no way to control bleeding unlike vitamin k used to reverse the effect of warfarin. While Coumadin (warfarin) may be a little less convenient, it has been the standard blood thinner for over 50 years and does not have the dismal record of Pradaxa.
In a December 2012 press release, Boehringer Ingelheim Pharmaceuticals announced findings from the RE-LY trial and four other Phase III trials concluding that a patient suffering a major bleed out from Pradaxa may fare better than a patient on warfarin. The company continues to deny bleeding is unmanageable and poses no greater a risk with Pradaxa.
The company presented those findings to other doctors at the 54th meeting of the American Society of hematology.
It is very unlikely that a patient will read a black box warning. Most patients rely on their doctor or pharmacist for advice; so an increased warning on a drug’s label may in reality make little difference when compared to the advice of one’s doctor that all blood thinners carry some risk.