Warns of Increased Blood Clot Risk With Birth Control Patch
A new study shows that women using
the Ortho Evra birth control patch have double the risk of developing
blood clots than those who take the pill, the US government said
on February 17, 2006. It did say, however, that the results were preliminary and did not
require immediate action other than advising women to discuss
the risk with their doctor.
results of the study and another that found no increased risk,
were made public in February 2006 by the patch's manufacturer.
"The results are preliminary and further evaluation is necessary
to understand what these results mean," Dr. Daniel Shames,
director of the division of reproductive and urological drug products
at US Food and Drug Administration, said at a briefing.
finding comes from one of two studies comparing the patch and
pill, said Ortho Women's Health & Urology, maker of the once-a-week
patch. The company is owned by Johnson & Johnson.
In 2005 an investigation by The Associated Press, citing federal
death and injury reports, found higher rates of blood clots in
women using the patch.
first study found no increased risk of clots but the interim results
from the second study suggested a twofold increase in the risk
of venous thromboembolic events, or clots in the legs and lungs,
in women using the patch, Ortho said.
because the confidence intervals of the results for the two forms
of contraceptive overlap, there actually may be no increased risk
from the patch or it may be more than twice, Shames said at a
briefing. He said the risk of a nonfatal blood clot is about one per year
in 10,000 women not using a contraceptive.
those using a hormonal contraceptive such as the patch or pill
the risk rises to between three and five, he said. "These
are fairly unusual events," said Shames. He noted that in
pre-approval testing of the patch on about 3,000 women there were
two reports of blood clots, but one involved a woman who had had
Percent More Estrogen
ongoing studies also are looking at the risk of heart attacks
and strokes among users of the two types of contraception. Currently
there is no difference but the numbers are small and it will take
another 18 months to see if a difference occurs, Shames said.
company said that the risk of clots remains rare and that they
have been reported as a potential risk of all hormonal contraceptives.
of the interim results comes four months after the FDA warned
women that the increased levels of hormones released by the patch
put them at higher risk of blood clots and other serious side
effects. Ortho said it shared the results of the latest studies
with the FDA.
to the patch label made in November 2005 warned women that they
would be exposed to about 60 percent more estrogen than those
who use birth control pills. Since
the patch went on sale in 2002, more than 4 million women have
investigation by The Associated Press found that patch users die
and suffer blood clots at a rate three times higher than women
taking the pill. About a dozen women died in 2004 from blood clots
believed linked to use of the patch, the AP reported. Dozens more
suffered strokes and other clot-linked problems.
officials warn that women who smoke should not use the patch,
since smoking increases the risk of stroke and heart attack.
Associated Press Writer Andrew Bridges contributed to this report
from St. Louis, MO
Reading, See: Ortho
Evra and Birth Control Pill.