Taking antidepressants? It’s usually not a problem, unless you’re also taking the breast cancer drug, tamoxifen. Recent studies show the two together could increase the chances of breast cancer returning after treatment is over.
In the study, women taking one of these three medications along with tamoxifen were about twice as likely to experience breast cancer a second time. (Celexa, Lexapro, and Luvox did not show the same results.)
It’s a bit of a shock, as antidepressants are often prescribed to ease depression caused by cancer, or to reduce the sometimes severe hot flashes caused by tamoxifen. In fact, over 25% of women experiencing hot flashes on tamoxifen are now prescribed antidepressants to manage the symptoms! But the interaction is not a good one. Tamoxifen interacts with a liver enzyme to become a tumor-fighter, but antidepressants block that same enzyme, which reduces the effectiveness of the cancer drug. Antidepressants that are stronger enzyme blockers have the strongest effect, so that’s why Paxil, Prozac, and Zoloft were more detrimental than the weaker blockers.
The study involved about 1,300 women taking tamoxifen between 2003 and 2005. Women taking the antidepressant/tamoxifen combo had a breast cancer recurrence rate of 13.9% compared to 7.5% for women only on tamoxifen.
What to do? There have been few studies on the matter, so the results aren’t gospel, yet. (One smaller study reported little risk in the tamoxifen/antidepressant combo, though it looked at the effects for a shorter amount of time and didn’t compare results with women on tamoxifen alone.) Still, there’s enough evidence here to raise concern. If possible, avoid the antidepressants, or ask your doctor for those less likely to interfere with tamoxifen’s effectiveness. Judy Gralow, M.D., breast cancer specialist at the University of Washington in Seattle, recommends Effexor to her patients. In the study, it had the weakest affect on tamoxifen.
Bottom line: Don’t think you need to stop taking the breast cancer drug. “Tamoxifen is a very important drug,” says Dr. David Flockhart, director of the Division of Clinical Pharmacology at the Indiana University School of Medicine, “and we don’t think women should stop taking it because of this.”
Have you changed antidepressants as a result of this study? Please share your experience.
Photo courtesy of jen_m_stewart via Flickr.com.
