Health Canada evaluating whether body weight affects the effectiveness of emergency contraceptive pill

Starting date:
January 30, 2014
Posting date:
January 30, 2014
Type of communication:
Information Update
Subcategory:
Drugs
Source of recall:
Health Canada
Issue:
Dosage
Audience:
General Public
Identification number:
RA-37771

Issue

Health Canada is evaluating the effectiveness of levonorgestrel-containing emergency contraception in light of new data that suggests these pills may be less effective in women over a certain weight.

Emergency contraception, also known as the "morning after pill," is taken by women up to 72 hours after unprotected sex or a contraceptive accident (such as a condom breaking), to prevent pregnancy. In Canada, there are four emergency contraceptivepills available, all of which contain the hormone levonorgestrel and are available without a prescription:

  • Next Choice (Cobalt Pharmaceuticals Company)
  • Norlevo (Laboratoire HRA Pharma)
  • Option 2 (Perrigo International)
  • Plan B (Teva Women's Health Inc.)

These pills contain a higher dose of levonorgestrel compared to regular birth control pills with this hormone, and work by preventing ovulation or fertilization of an egg. They have no effect if a woman is already pregnant.

Health Canada is aware of the recent statement by the European Medicine's Agency (EMA) regarding this issue. Health Canada, like the EMA, is assessing new data suggesting that a higher body weight could reduce the effectiveness of emergency contraceptives. It is also looking at whether labelling changes will be needed for all levonorgestrel emergency contraceptive products to better reflect the patient population in which these products are effective.

As noted in the EMA statement, the product labelling for the drug Norlevo was recently revised in Europe to add the following information: "In clinical trials, contraceptive efficacy was reduced in women weighing 75 kg or more, and levonorgestrel was not effective in women who weighed more than 80 kg."

Health Canada will take appropriate action as required, such as working with the manufacturers to update drug labels and notify Canadians of new information.

What you should do

Follow the directions for use outlined on the product’s label; do not exceed dosing recommendations. Talk to a healthcare professional such as a doctor or pharmacist with any questions or concerns about emergency contraception.

Report health or safety concerns

To report a side effect to a health product to Health Canada:

  • Call toll-free at 1-866-234-2345
  • Visit Health Canada's Web page on Adverse Reaction Reporting for information on how to report online, by mail or by fax.

Media enquiries

Health Canada
(613) 957-2983

Public enquiries

(613) 957-2991
1-866 225-0709