Cheaper blood thinner just as effective, study says

By Andrew Stern

CHICAGO (Reuters) – Injections of the blood thinner heparin
treat blood clots just as effectively as a top-selling version
that is many times more expensive, researchers said on Tuesday.

To treat deep vein thrombosis, which appears most often as
blood clots in the legs, injections of low-molecular weight
heparin such as Sanofi-Aventis’ blockbuster Lovenox and
Pfizer’s Fragmin have been increasingly seen as more convenient
and effective than original heparin.

The original blood thinner, called unfractionated heparin
and derived from pig tissues, is given intravenously in the
hospital and patients are closely monitored.

The newer, more expensive version of heparin is extracted
from the original and has smaller molecules, meaning it is less
likely to bind to a protein in the body and presumably making
it more predictable and convenient to use. It is injected just
once a day, and can be administered by the patient.

But the study by McMaster University researchers found a
weight-adjusted dosage of the original, much-cheaper heparin —
a six-day course would cost $37 versus $712 for
low-molecular-weight heparin — can be injected twice daily
without an expensive hospital stay or in-hospital testing.

“That was the underlying reason why we did the study: it is
not necessary to do blood testing,” study author Clive Kearon
said in a telephone interview.

Blood clots reappeared in less than 4 percent of 700
patients whether they injected the original heparin or
low-molecular weight heparin. The rate of major bleeding was
also comparable in the two groups.

“This study will open the possibility of an expanded role
for inexpensive, ordinary heparin,” Kearon said, noting that
most such studies are sponsored by drug companies that may be
less motivated to recommend a treatment that costs less.

The study, which was published in the Journal of the
American Medical Association, was funded by The Heart and
Stroke Foundation of Ontario.

“If you never do a study funded by a peer-reviewed agency,
you’re never going to reduce the cost of therapy,” Kearon said.

The difference in cost of the two blood thinners is not as
great in Canada or in Europe, where low-molecular weight
heparin is more commonly used.

According to The American Heart Association, deep vein
thrombosis occurs in about 2 million Americans a year and an
estimated 600,000 of those develop a pulmonary embolism in the