Makers of the Norlevo morning-after pill are warning its emergency contraception may be ineffective on women over a certain weight.
HRA Pharma said that the efficiency of its active ingredient, levonorgestrel, is reduced in women over 165 pounds and ineffective in women over 176 pounds, although various health practitioners have been quoted in Canadian news media saying the warning is precautionary and imprecise.
The pills are currently available over the counter at pharmacies in Ontario to all women without a prescription. In Canada, there are contraception options containing levonorgestrel including Norlevo, Plan B, Alesse and Mirena. Norlevo and Plan B are both emergency contraception pills, while Alesse is a daily oral contraceptive pill and Mirena is an intra uterine device (IUD).
Health Canada is aware of Norlevo’s plans to change its labels and are assessing all relevant information such as prescribing practices, pattern of use, availability and treatment practices.
“Health Canada is assessing the available data on the effectiveness of this product and will take appropriate action if required, such as working with the manufacturer to update the product labeling and notifying health care professionals of the change,” said Health Canada spokesman Gary Holub.
“My biggest concern is why this is coming out now,” said Anne Rochon Ford, executive director of the Canadian Women’s Health Network. “It raises questions about who they were studying the medication on when they were studying it in the clinical trial phases.”
The weight noted in the warning is not an unusually high weight these days.
“The announcement did not make any links to obesity or didn’t use any kind of that language or talk about BMI (Body Mass Index),” said Rochon Ford.
Ford raised the point women should be concerned with new contraceptive products that come onto the market.
“When something new comes onto market, there’s a lot of hype but yet we don’t have the full story.”
She said the drug or medical device is still essentially being tested as it’s going into a larger population following clinical trial phases.
However, Dr. Erika Feuerstein from the Bay Centre for Birth Control said that nothing has changed.
“It’s one study, and the numbers are low so we don’t really know,” said Feuerstein. “The most effective thing for post-coital contraception is the post-coital IUD. It’s 99 per cent effective and should be the first thing women are offered.”
If a woman who is heavier does not want the IUD, Dr. Feuerstein would still offer her the Plan B morning-after pill. If a woman is concerned about her birth control pills or IUD Dr. Feuerstein suggests they speak with their doctors.