Antidepressants: the news is depressing when they are combined with tamoxifen

Breast cancer survivors who have had chemo brain, faced with an array of post-chemo treatment decisions, are now presented with an array of even more complex decisions as a result of research reported at this week's American Society of Clinical Oncologists (ASCO) annual meeting.

An Associated Press story ran the headline "Study: Drug combos may raise breast cancer risk" and described conclusions from a new study on combining certain antidepressants with a leading hormone suppressant medication tamoxifen:

About 500,000 women in the United States take tamoxifen, which cuts in half the chances of a breast cancer recurrence. Many of them also take antidepressants for hot flashes, because hormone pills aren't considered safe after breast cancer.

Doctors have long known that some antidepressants and other medicines can lower the amount of tamoxifen's active form in the bloodstream. But whether this affects cancer risk is unknown.

The new study, reported Saturday at a cancer conference in Florida, is the largest to look at the issue. It found that using these interfering drugs — including Prozac, Paxil or Zoloft — can virtually wipe out the benefit tamoxifen provides.(emphasis mine).

At the same conference, another study presents findings that would seem to support one of those drugs, Paxil, as an chemo brain treatment. A Wordpress blog interpreted the findings of a study to recommend antidepressants as a treatment for chem brain. The study involved only self-report of memory problems, and no physiological measures. While evidence exists that shows anxiety can have a serious impact on memory, little biochemical evidence exists to warrant antidepressant treatment for memory problems.

The news from ASCO regarding the negative effects of antidepressants when combined with tamoxifen should give all cancer survivors (not just breast cancer survivors) and medical professionals pause: the long-term consequences and the biomechanisms from selective serotonin reuptake inhibitors (SSRIs) are not sufficiently known to warrant widespread prescribing without very close follow-up.

The information explosion creates a challenge for cancer survivors: how to stay abreast of reputable studies that may affect them, and how to ensure their physicians are able to use that information in treating them.

www.healthafterchemo.com will continue to identify and publish news important for the cancer survivor community.