Blood-thinner dose errors can cause bleeding:study

CHICAGO (Reuters) – Some heart patients are given too large
a dose of blood thinner at the hospital, which can lead to
excessive bleeding, researchers said on Tuesday.

The dosing errors found in 42 percent of more than 30,000
cases stemmed from factors including physicians using a “one
size fits all” dosing criteria, underestimation of the
importance of using the right dosage or a lack of information
about a patient’s weight or other indicators.

The dosing errors with three classes of blood thinners —
unfractionated heparin, low-molecular-weight heparin and
glycoprotein IIb/IIIa inhibitors — most often affected
patients more vulnerable to bleeding such as the elderly,
women, low-weight patients, diabetics, or patients with
diminished renal function, the study said.

The purpose of quickly administering blood thinners, or
antithrombotic therapy, is to prevent another heart attack or
stroke, the report published in the Journal of the American
Medical Association said.

Lead author Karen Alexander of Duke University in Durham,
North Carolina, wrote that experts recognize that most drugs
must be administered within a “therapeutic window” — too much
or too little can do harm.

Of the patients at 387 U.S. hospitals studied over nine
months, up to 15 percent of those who received excessive doses
of blood thinners had major bleeding events likely attributable
to the too-large dose.

“Patients receiving excess antithrombotic (anti-clotting)
therapy also had higher mortality and longer length of
(hospital) stays,” Alexander wrote.