Monday, November 12, 2012

Most Dangerous Drug in America?

Our trauma service has been seeing more and more elderly patients admitted for closed head injuries who are taking the blood-thinning agent Pradaxa.  As this NY Times article indicates, this is not a positive development.  Pradaxa is a direct thrombin and factor Xa inhibitor used in patients at high risk for developing cerebrovascular or systemic embolic events (i.e. patients with atrial fibrillation).  It is a newer alternative to the old standby, coumadin (warfarin) therapy.

The problem is that the RE-LY study (the randomized trial that conformed the efficacy of Pradaxa) also demonstrated a higher bleeding risk than warfarin.  The results from real life application should not be surprising:
But almost as soon as doctors started prescribing Pradaxa, concerns surfaced about its safety. Pradaxa was identified as the primary suspect in 542 patient deaths reported to the F.D.A. in 2011, and was linked to more reports of injury or death than any of the more than 800 drugs regularly monitored by the Institute for Safe Medication Practices, a nonprofit based in Pennsylvania that monitors medicine safety.

As trauma surgeons, we are handicapped in two ways.  One, Pradaxa is not monitored by checking typical coagulation laboratory parameters (i.e. INR).  These patients will have normal INR values.  And if the patient shows up obtunded, unable to give a history or provide evidence that he/she is taking Pradaxa, then we will have no idea that that patient is at high risk for continued hemorrhage.  Two, there is not an antidote to the anticoagulation effects of Pradaxa other than emergent hemodialysis.  With coumadin we can reverse the coagulapathy fairly rapidly with intravenous Vitamin K, Factor IX, and fresh frozen plasma.  With Pradaxa, there is nothing to do but wait (typical half life of the drug 2-3 days) and hope the nephrologist can extract the drug over a 6-12 hour time frame.  In the setting of acute intracranial hemorrhage, such a delay is life threatening.  To prescibe this drug to an elderly patient who has a history of ambulatory unsteadiness or dementia is utter foolishness. 

I get why there has been a move to prescribe this death trap.  Monitoring INR levels in patients on coumadin is expensive and annoying.  Much easier to simply put a patient on Pradaxa and call it a day.  Check back in 3 months.    But the consequences are unacceptable.  Pradaxa made over a $1 billion for its German pharm company over the past two years.  They better be socking away huge chunks of that windfall into their litigation slush fund.....

1 comment:

witk2005 said...

Hi. Great post. I take coumadin and have for the past 22 years and will not switch to this medicine. I am hoping all PCP's and or internal medicine doctors read this before prescibing this to their patients. I get that the older population not wanting to have the INR draw, but the alternative "should not be an option." I have been in the situation of having the frozen plasma to thicken up the blood before a non scheduled surgery. I am thankful for an informed PCP and surgeon. Kiddos to you and your continuing posts.