Bad Combo? Some antidepressants may hamper breast cancer drug
By Nathan Seppa
By impeding estrogen’s cancer-promoting properties, the drug tamoxifen has enabled thousands of breast cancer patients to fend off recurrences. But taking tamoxifen increases the frequency of hot flashes, and many women use antidepressants to limit this side effect.
Researchers now report that popular antidepressants called selective serotonin reuptake inhibitors (SSRIs) might diminish the effectiveness of tamoxifen by limiting its conversion into medicinally important agents.
David A. Flockhart of the Indiana University School of Medicine in Indianapolis and his colleagues there and elsewhere measured one of these compounds, called endoxifen, which binds to estrogen receptors on cells and slows cancerous growth. In the Jan. 5 Journal of the National Cancer Institute, they report that women taking tamoxifen and an SSRI had lower blood concentrations of endoxifen than did similar women on tamoxifen who weren’t using an SSRI.