An article was published in the NEJM on November 24, 2011 entitled, "Emergency hospitalizations for adverse drug events in older Americans" (N Engl J Med 2011; 365:20022-2012) that is truly sobering.
This article is written by authors for the CDC and forms the justification for a $1 billion federal program called Partnership for Patients. The purpose of this program is to reduce adverse drug events by 20% by 2013. At the present time, roughly 100,000 hospitalizations occur each year following an adverse drug event. Reducing this number would save considerable money and significantly decrease the morbidity and mortality of these events.
It seems that four drugs or classes of drugs account for 67% of all emergency adverse drug event hospitalizations in adults 65 years or older.
Contestant: “Alex, I’ll take Drugs that will kill you or save you for $100”
Alex: “What drug is used to kill rats?”
Contestant: “Warfarin”
Alex: “Correct."
By the way, the other drugs are insulin, antiplatelet agents (aspirin, Plavix), and oral hypoglycemic agents in order of importance. Nearly half of the hospitalizations for adverse drug events occurred in patients 80 years or older. Women accounted for close to 60%.
Yes , it turns out that in 33% of the 67% of events warfarin is the culprit. These events have multiple root causes. Many of these events are fatal. All cause problems. The most common manifestations are gastrointestinal bleeding, urinary tract bleeding and the dreaded, and often fatal, intracranial bleeding.
Let’s stop for a moment and look at warfarin dosing. The barriers for success here are quite high. First and foremost, warfarin needs monitoring, and the process is quite onerous. First, the patient must come to the office or go to a lab. Then, the lab result needs to be obtained, and the patient needs to be called and directed to take the same dose or change the dose. If the dose is changed, it needs to be checked again. It turns out that even in studies of anticoagulation, such as the ones I have discussed in the blog, the percent of time that study participants are adequately anti-coagulated is woefully small. These patients are much more difficult to control than study patients as they are older and at times more frail.
To top it all off, the reimbursement for the time and liability of this is pitiful. In my office, we use point of care machines which give us an immediate answer, but the cost of the cassettes for the test is barely covered.
Warfarin is notoriously affected by other medications. In our healthcare world of polypharmacy and poly doctors, patients often do not know what drugs they are taking or their doses. Further, as I have blogged about before, generics are allowed to be 80-120% of the drug. This reeks havoc on the dosing of warfarin. A couple of doses of antibiotics for the myriad of reasons that they are given out play havoc with warfarin and is the most common reason for catastrophe.
As my patients get older, I try to balance their needs with the reality of all their problems. I believe that there comes a time that patients have more risk than benefit if taking warfarin. This line varies, and it is important to seek as balanced decision as possible. This article points out just how critical this problem is.
This is an important problem and goal. I believe it will be very hard to reduce adverse drug events especially those related to warfarin. Just because it is hard does not mean we should not try.
We need to do better.