Tamoxifen is a widely-used breast cancer drug which 500,000 women in the United States are taking to prevent their estrogen-dependent breast cancer from recurring. The FDA plans to warn doctors about a recent breakthrough in which evidence has been gathered about the interaction between tamoxifen and antidepressants. Certain anti-depressants, when taken with tamoxifen can actually increase a women’s risk of breast cancer recurrence by two-fold.

The study used to discover these findings involved 1300 women over a one year period of time. All the women were monitored, their breast cancer recurrence rates were compared in different groups of women taking no antidepressants, Zoloft, Paxil, and Prozac all along with tamoxifen. The results yielded a 7.5% recurrence rate for women not taking antidepressants and a recurrence rate of 16% for women taking any of the 3 mentioned types of antidepressants. Other antidepressants studied that did not significantly affect breast cancer recurrence rate were Luvox, Celexa, and Lexapro.

Now that the FDA has proof through clinical outcomes that this drug interaction can actually increase a women’s risk of recurring cancer, the FDA is opting to add information to tamoxifen’s label.  Although placing information on FDA-approved labels is a start to informing health care providers and patients about this drug interaction, further vehicles will be needed to educate the breast cancer survivor community on this issue.

Medco’s cheif medical officer, Robert Epstein, explained that over 500,000 U.S. women are taking tamoxifen, of which 30% are simultaniously perscribed antidepressants.  This indicates that many health care providers are not aware of this dangerous interaction, so patient awareness is key, especially for patients treated by multiple doctors.

This article was written by Amy Shah, however facts were obtained from an article by Jennifer Corbett Dooren.