The manufacturer of French morning-after pill NorLevo has announced that the drug is ineffective in women who weigh more than 80 kilograms. The statement was made at a press conference on Tuesday, and comes in the wake of a 2011 study into the one of the drug's active ingredients, levonorgestrel. The study found that contraceptives with levonorgestrel as an active ingredient failed to contracept in women over 80kgs, and that the effectiveness of the drug decreased dramatically after 75kgs.
Frederique Welgryn of HRA Pharma, the company supplying NorLevo, said that the results of the study conducted by the Edinburgh University in 2011 were "quite surprising", and the last few years have seen "a lot of discussions" about contraceptives' efficacy in overweight or obese patients.
The information on drug packaging is being substantially revised. From next year it will feature a new leaflet warning women about the weight limits of the drug.
The results of the 2011 study affect all drugs which have levonorgestrel as an active ingredient. Pressure is mounting on all manufacturers of the morning-after pill to immediately change the accompanying drug information.