Study finds antidepressants may pose higher risk of recurrent breast cancer

ORLANDO Recent studies showed several selective serotonin reuptake inhibitors reduced the effectiveness of the breast cancer drug tamoxifen when used concurrently.

According to Medco Health Solutions, three commonly used SSRIs — Prozac (fluoxetine), Paxil (paroxetine) and Zoloft (sertraline) — all belong to a group of drugs known as CYP2D6 inhibitors. Such antidepressants prescribed in conjunction with tamoxifen posed a higher risk for recurrent breast cancer, Medco concluded.

“We’ve known that these CYP2D6 inhibitor drugs block the activation of tamoxifen chemically, but this is the first time there’s evidence that these drugs are putting women at a much higher risk for recurrent breast cancer,” said Robert Epstein, Medco’s chief medical officer and one of the study researchers. “It’s also the first time that a comparative analysis has been done looking at various SSRIs and what’s clear is that several of these drugs are extremely risky for women to take with tamoxifen, while others don’t present a problem.”

With nearly 30% of the 500,000 women taking tamoxifen in the U.S. using an antidepressant as well, Medco has been actively working to alert physicians and patients.