Effectiveness of Plan B Increases When Combined With Arthritis Drug

New research found that levonorgestrel, also known as Plan B or the morning-after pill, may be more effective at preventing pregnancy when taken with a common anti-inflammatory medication.

Plan B, or levonorgestrel, is an emergency contraception medication that reduces the chance of pregnancy by preventing or delaying ovulation. Levonorgestrel is a progestin-only drug and does not cause abortion. It must be taken within 72 hours after unprotected sex to prevent pregnancy. Still, Plan B works best when taken within a day of unprotected sex, as the drug's effectiveness decreases from day one to day three.

However, a new study found that combining the anti-inflammatory drug piroxicam with levonorgestrel may boost the effectiveness of the morning-after pill and help it remain effective for up to three days.

In the randomized, double-blind, placebo-controlled trial published on August 16 in The Lancet, researchers recruited 860 women in China between 2018 and 2022 who requested emergency contraception within three days of unprotected sex.

Half of the participants received levonorgestrel and a placebo, and the other half took levonorgestrel and 40 milligrams of piroxicam. Then, the scientists noted who became pregnant by following up one to two weeks after the participants' expected period.

After reviewing the data, the researchers found that levonorgestrel plus piroxicam prevented 94.7% of potential pregnancies. In contrast, levonorgestrel with a placebo prevented 63.4% of expected pregnancies.

The common side effects noted were nausea, fatigue, abdominal pain, headache, and dizziness.

Still, unlike similar anti-inflammatory drugs available over the counter, piroxicam is only available by prescription in the United States and other countries.

However, according to the Associated Press, study author Kristina Gemzell Danielsson, head of Women and Children's Health at Sweden's Karolinska Institute, says over-the-counter medications like ibuprofen could have the same effect.

Gemzell-Danielsson also suggests that while these medications might be less effective than longer-acting piroxicam, there would be no risks to women who took ibuprofen with Plan B.