The Pros and Cons of Tamoxifen

Over the years, millions of women—including yours truly—have taken a hormonal therapy known as tamoxifen to prevent a recurrence of their breast cancer. And, over this same period, many of us have raised a question: What, if anything, is tamoxifen doing to my brain? 

Tamoxifen is a wonder drug for certain: Taken correctly, it prevents recurrence in about half the women on it. Its side effects, however, are so dreadful that quite a few women stop taking it before it’s worked its magic.

In fact, we cancer survivors know all about a drug that jumbles up our brain function: For a long time, we’ve noticed that chemotherapy drugs can cause something we call chemo brain—a very real sense of not being able to remember things, or of feeling like our ability to concentrate is somehow “off.” We’ve often wondered if tamoxifen could possibly be burdening us in the same way.

Well, a recent study from the University of Rochester Medical Center, published in the Journal of Neurosciences, has at last confirmed that tamoxifen does indeed cause the women on it to experience a “mental fog.”

So please, ladies! If you are on tamoxifen, read on and finish this blog. Hang in there and do not stop taking it!

A pair of discoveries

Besides validating our suspicious about tamoxifen’s effects on our minds, the researchers in Rochester made a second discovery: In animal experiments, they have established that a substance known as AZD6244 counteracts the awful side effects of tamoxifen, and can even rescue brain cells from the damage the drug can do.

That’s right—these scientists have proved, at least in mice, that AZD6244 essentially eliminates the tamoxifen-induced killing of brain cells. Of course, the hope now is that their experiments will also show that AZD6244 can achieve the same result in the human brain.  

So what to do?

  • First of all, keep up-to-date regarding the research in this area.
  • Second, do not stop taking tamoxifen without your doctor’s permission.
  • Third, know that our troubles with concentration and the cloudy thinking associated with tamoxifen are short term. (Though I do know a few women who have used their “mental fog” as their excuse for more than 30 years!)
  • Fourth, always remember that tamoxifen, even though its grim side effects can make our lives miserable at times, prevents breast cancer from recurring in almost 50 percent of women taking it—and that a cure for its side effects may be around the corner!

©1996-2013, Johns Hopkins University. All rights reserved. Disclosure: The information provided here is compiled by The Johns Hopkins University School of Medicine with editorial supervision by one or more of the members of the faculty of the School of Medicine pursuant to a license agreement with Yahoo! Inc. under which the School of Medicine and its faculty editors receive licensing fees and payment for services rendered within the scope of the License Agreement. Johns Hopkins subscribes to the HONcode principles of the Health on the Net Foundation.

LEAVE YOUR COMMENT

Follow Yahoo Health on and become a fan on

Follow @YahooHealth on
Related Health News