Pharmacists urged to explain potential effect of body weight on emergency contraception

The Faculty of Sexual and Reproductive Healthcare (FSRH) has urged pharmacists and doctors to explain to patients that the emergency contraceptive pill can be ineffective in women weighing 11 stone or more, or with a body-mass index of 26 or above. 

The appeal comes following new FSRH guidance on emergency contraception, published in March 2017, which aims to summarise the available evidence on emergency contraception for healthcare professionals.

In 2014, the European Medicines Agency, which evaluates medicinal products for use in Europe, concluded that there is limited evidence showing oral emergency contraception to be less effective in women with higher body weight. But the FSRH’s guidance states that “women should be informed that it is possible that it could reduce the effectiveness”.

Jane Dickson, vice president of the FSRH, highlighted that 15 stone was the “danger point” for some women, but 11 stone has been suggested as the weight that may start to pose risk. Consequently, the FSRH guideline development group recommends that if a copper intrauterine device is not indicated, women can be offered ulipristal acetate (EllaOne), but if this is not suitable, a double dose of levonorgestrel (3mg) can be used.

“The coil’s effectiveness is not affected by a woman’s weight as it works differently to prevent fertilisation – it’s toxic to sperm and eggs and works locally,” says Dickson.

Gedeon Richter Ltd, the manufacturers of Levonelle (levonorgestrel), one of the pills thought to be affected by weight, said: “We are aware of some uncertainties regarding the efficacy of levonorgestrel emergency contraceptive tablets in women with a BMI greater than 30, but as a result of the limited number of patients involved in these studies, the relevance of these data are questionable.

“As a company that is responsible for women’s health, we are considering updating the summary of product characteristics regarding the effect of increased weight/BMI on the effectiveness of oral levonorgestrel containing emergency contraceptives. The available evidence and data is being reviewed and analysed and the company will make a well-based and thorough decision on this after the evaluation procedure.”

• On 10 April 2017, this story was amended to include further guidance on copper intrauterine device contraindication.