By Pat Anson, Editor

Health experts have warned for years about the side effects of over-the-counter pain relievers – everything from liver failure to heart disease to hearing loss.

Now researchers are saying that Aleve and some other non-steroidal anti-inflammatory drugs (NSAIDs) reduce the fertility of women so significantly they could potentially be used as an emergency form of contraception.

The results of a small study presented at the European League Against Rheumatism Annual Congress show that three NSAIDs --  naproxen, diclofenac, and etoricoxib -- inhibited ovulation in women after just a few days of treatment.

Naproxen, diclofenac, and etoricoxib are the active ingredients in several brand name drugs sold around the world, including Aleve, Voltaren, and Arcoxia, respectively. Etoricoxib is not approved for use in the United States.

Thirty nine Iraqi women of childbearing age who suffered from back pain took part in the study; receiving diclofenac (100mg once daily), naproxen (500mg twice daily), etoricoxib (90mg once daily), or a placebo.

Treatment was given for 10 days from day 10 of the onset of their menstrual cycle, with their progesterone levels and follicle diameter analyzed via blood sample and sonography.

“After just ten days of treatment we saw a significant decrease in progesterone, a hormone essential for ovulation, across all treatment groups, as well as functional cysts in one third of patients,” said study investigator Professor Sami Salman, Department of Rheumatology, University of Baghdad.

“These findings show that even short-term use of these popular, over-the-counter drugs could have a significant impact on a woman's ability to have children. This needs to be better communicated to patients with rheumatic diseases, who may take these drugs on a regular basis with little awareness of the impact.”

Of the women receiving NSAIDs, only 6.3% taking diclofenac, 25% taking naproxen, and 27.3% taking etoricoxib ovulated, compared with 100% of the control group that was not taking a pain reliever.

The dominant follicle remained unruptured in 75% of the women taking diclofenac, 25% taking naproxen and 33% of the patients receiving etoricoxib. Rupturing of the dominant follicle and the subsequent release of an oocyte (unfertilized egg), is essential for ovulation to occur.

“These findings highlight the harmful effects NSAIDs may have on fertility, and could open the door for research into a new emergency contraception with a more favorable safety profile than those currently in use,” said Salman.

NSAIDs are among the most common pain relief medicines in the world. Every day more than 30 million Americans use them to relieve pain, lower fever and reduce inflammation.