A French contraceptive
maker said Tuesday its morning-after pill doesn't work when taken by women who
weigh more than 80 kilograms (176 pounds) and plans to change its labels to
The decision to change its
labels by HRA Pharma is based on a previous study of levonorgestrel, one of the
active ingredients in its Norlevo emergency contraceptive, said Frederique
Welgryn, HRA Pharma's head of women's health.
Some doctors said heavy
women shouldn't assume emergency contraception won't work for them and that
they should talk to a health professional or consider alternatives like a
copper IUD, a birth control device that can be fitted on the uterus.
Norlevo is not sold in the
US but another drug with the same active ingredient is widely available.
Welgryn said a dose of
HRA's drug contains 1.5 mg of levonorgestrel, identical to that found in Plan B
One-Step, manufactured by Teva Pharmaceuticals in the US Denise Bradley, a
spokeswoman for the company, declined to comment.
The Food and Drug
Administration is currently reviewing the issue and will determine "what,
if any, labelling changes to approved emergency contraceptives are
warranted," according to spokeswoman Erica Jefferson in an email.
Welgryn said that while the
results of the study conducted by the University of Edinburgh in 2011 were
"quite surprising", the last few years have seen much discussion
about contraceptives' efficacy in overweight or obese patients.
HRA Pharma Chief Executive
Erin Gainer estimated that millions of women across Europe use emergency
contraceptives identical to Norlevo. Gainer declined to give sales figures for
Anna Glasier, a lead
researcher in the 2011 study, said that their research wasn't designed to look
specifically at the effect of weight on emergency contraception. She said their
study only included about 1 700 women.
"It is not my place to
comment as to whether the company's decision to change advice is
premature," she said in an email.
She also noted another
previous analysis that found there was no solid evidence to show that hormonal
contraceptives were less effective in overweight women, but the quality of the
studies was low.
Best within 24 hours
The morning-after pill
contains a higher dose of the hormone in regular birth control pills. Taking it
within 72 hours of rape, condom failure or just forgetting regular
contraception can cut the chances of pregnancy by up to 89 percent, but it
works best within the first 24 hours. If a woman is already pregnant, the pill,
which prevents ovulation or fertilization of an egg, has no effect.
HRA began the process of
consulting with French regulators about changing the pill's labelling in 2012
and it has taken until now for Europe's drug regulators to approve the change,
The new warning also says
that the drug's efficacy is reduced in women who weigh more than 75 kilograms
(165 pounds), and it is ineffective in women who weigh more than 80 kilograms.
Dr Diana Mansour, a
spokeswoman for Britain's Faculty of Sexual and Reproductive Healthcare, said
in overweight and obese women the drug probably gets absorbed into their fat
more quickly and doesn't have enough time to work in their bodies.
"It has less of a
chance to delay ovulation and there are lower levels (in the blood) of the drug
to have an effect," she said. Mansour said there wasn't enough information
to know if simply giving obese women a higher dose of the drug would solve the
Solving the problem
In the UK, doctors haven't
been given any advice to stop giving overweight or obese women Levonnelle,
which contains the same active ingredient as Norlevo.
Lynn Hearton, clinical lead
for the FPA sexual health charity, said any overweight or obese women concerned
about emergency contraception should speak to a medical professional.
"It is particularly
important we don't put some women off taking emergency contraception because
they think it won't work anyway," she said.
She said women should
consider using an IUD, which can be inserted in the womb up to five days after
HRA markets Norlevo in
about 50 countries worldwide. It began marketing the pill in France in 1999.
It will begin printing the
warning on packaging in the first half of 2014.