LONDON (AP) — The European Medicines Agency says it has started a review of emergency contraceptives to see if they work less well in heavier women.
In November, French drug maker HRA Pharma announced its morning-after pill Norlevo was less effective in women weighing more than 75 kilograms (165 pounds) and that it didn't work for women more than 80 kilograms (176 pounds). HRA Pharma changed its labels to warn patients after consulting with European regulators.
In a statement on Friday, the EMA said it would evaluate new data suggesting that a high body weight could compromise the effectiveness of the morning-after pill.
"This is an efficacy issue," said Monika Benstetter, an agency spokeswoman. "We need to find out what the association is with (body mass index) and if there is a cut-off threshold for when the medicine becomes less effective."
HRA Pharma's Norlevo contains levonorgestrel, the same active ingredient in other medicines including ellaOne, Levonnelle and Levodonna. One of the studies that prompted the label change on Norlevo found the risk of emergency contraception failing was higher in women with a body mass index higher than 25, considered to be overweight.