tamoxifen and antidepressants--some info worth exploring

By Jolene Boyd Saturday, January 19, 2008

- A
- A
- A

I have been doing a little research and happened, quite accidentally, upon some disturbing information. Apparently there is a decent amount of research out there (from as far back as 2003) that discusses a problematic drug interaction between tamoxifen and many antidepressants (mostly the serotonin-reuptake inhibitors-SSRIs-but also bupropion and some of the trycyclic antidepressants.) Turns out that these antidepressants (and not a short list of other drugs, I might add) are metabolized by the same genes that tamoxifen is and have been found to inhibit the metabolization of tamoxifen when taken together. Because tamoxifen has to be metabolized into endoxifen to have the therapeutic effect for which it is prescribed in the case of breast cancer, this inhibition by certain drugs renders the tamoxifen essentially ineffective.

You might guess this is concerning to me because I have been taking bupropion (Wellbutrin) for quite a few years (long before bc dx) and have been taking tamoxifen since Nov 2007. I can't even remember how many times I have repeated my list of "current medications" to various docs, nurses, PAs, you name it. Pretty simple. Bupropion and a multi-vitamin. Ibuprofen or acetaminophen as needed. Not once has there been even so much as a glimmer of recognition that the bupropion could make the tamoxifen useless.

I guess I am doing a shout-out here because I found this information while searching various community postings at breastcancer.org...and there has been a TON of discussion about it there, but when I tried to search for it here I found exactly nothing about this problematic interaction. Here are a few links that people may want to check out if they are currently using an antidepressant. I will warn you that the information was a bit upsetting to me on several levels, but my husband pointed out that I spend little time in the "denial stage" and we are discussing how to move forward with this.

http://mayomedicallaboratories.com/media/articles/communique/mc2831-0107.pdf

http://jop.ascopubs.org/cgi/content/full/1/4/155

http://community.breastcancer.org/topic/78/conversation/693373 (this is a discussion thread but there are several entries as you scroll down that list info and links about this issue.)

Celebrating Renewed Hope...by walking 60 miles!

Comments (8) | Add comment

Lila de Tantillo, Health Guide

2/ 1/08 6:02pm

Jolene, thanks for your excellent question on the possibility of a drug interaction between tamoxifen and drugs like Paxil. I spoke to a few experts in the field, and their research thus far has substantiated such concerns. Here's a link to the article, I hope you find it helpful:

http://www.healthcentral.com/breast-cancer/c/9847/19911/paxil-pose/

Jolene Boyd

2/ 2/08 12:27am

Lila,

I posted a comment to the article, but just wanted to again say THANK YOU. Our lives require vigilance so being able to share with others is critical!

Thanks again! Jolene

Anonymous

1/11/09 2:13pm

I have been on wellbutrin since my 2004 BC diagnosis, Tamoxifin since 2005. Not once, was anything mentioned about possible interactions with my meds.With the head knocker of cancer, I didn't realize it was my job to find this out. Don't oncologists go to seminars etc. for all this? I just would have wanted the info to be presented to me, then let me make the decision of whether I'd want to stay with my anti-depressant or not. I found all this out because of a routine visit to pick up my meds. The pharmacist said the insurance company (not new) just decided that they wouldn't pay because of this risky interaction! What?! Totally out of the blue. My oncology nurse overrode this, but how good do I feel now? I've cut my wellbutrin in half and may wean myself off. I've been on tamoxifin for FOUR years!

My sister's oncologist now wants to give her a shot to obliterate her ovaries...Because i just found out this info and told her? Something's not right. What choices?

Jolene Boyd

1/11/09 4:30pm

Believe me, I truly appreciate your frustration...I think I realized some time ago that doctors are only human too and if you think about all the new (and sometimes old) research that is available all the time and that insurance companies only pay doctors for them seeing patients and performing procedures, it becomes much easier to understand how doctors may not know about things such as drug interactions or...you name the issue. When I talked to my oncologist about it, he WAS aware of the interaction with SSRIs (particularly Paxil), which is what MOST of the research has tested. Wellbutrin in NOT an SSRI. I found the information about the possibility of a Wellbutrin interaction through a very round-about path and it was that I pursued because it was very relevant to me. Since there are probably a lot more people on the various SSRIs than on Wellbutrin, strictly speaking a doctor would be able to serve more patients by reading up on that kind of drug. I think it became particularly relevant when it was discovered some docs were prescribing the SSRIs NOT for depression at all but to treat the side effects of tamoxifen. And with no research to suggest the REASON for the symptom abatement, docs started prescribing SSRIs for that purpose. My understanding is that now, with more research, they have realized that it is likely the SSRIs ease side effects of tamoxifen because they actually reduce the effectiveness of tamoxifen. OOPS. Although I, too, am frustrated by that, in reality that's just how our systems work. So what can we do? There is no having your cake and eating it too...if you want to know more about things that are relevant to you, sometimes you have to dig a little (or a lot) yourself and ask questions and challenge those "in charge" and talk to someone else if you don't get an acceptable response.

My apologies for a bit of a diatribe, but I felt like it needed to be put out there. Hindsight is 20/20, as they say, and doctors can't give advice that they don't know about. I did find it VERY interesting that your insurance company seems to have someone who discovered this research, though! Believe me, even now it still isn't the "standard of care" around here and I live in the state where some of this research has been (and hopefully is being) conducted (at the Mayo Clinic in MN). Let me know if I can offer any other support with this issue.

Jolene

Bryan

6/12/09 12:54pm

Jolene-

Did you see this article published late last month?

New Study: Antidepressants Commonly Prescribed with Tamoxifen Put Women at Much Higher Risk for Recurrent Breast Cancer (http://sev.prnewswire.com/medical-pharmaceuticals/20090530/NY2489130052009-1.html)

Jolene Boyd

6/12/09 7:32pm

Yes, I did. Thanks for the head's up, though! Funny that I feel like the medical community (or the media??) is just catching up with me and my research--just a "lowly" breast cancer survivor! But I fully intend to survive and thrive, so no way I'm going to avoid my due diligence in this matter! My oncologist still thinks it's a bit overkill that I switched antidepressants, but it's my life, so I'll do as I please! Jolene

Anonymous

8/19/09 8:19am

OMG ! I had to have a hysterectomy bcuz tamoxifen was giving me uterine cancer. And now I find out it probably wasn't even doing me any good bcuz I was also on bupropion !!! Which I told them at every appt. Just goes to show, don't depend on others, do your own research. Wish I'd found this sooner.

tamoxifen and antidepressants--some info worth exploring

Ask a Question