Category Archives: CYP2D6

Drugs not to take with tamoxifen: CYP2D6 inhibitors

For quick reference, here is my lay understanding of the list of drugs not to take with tamoxifen, thanks to

CYP2D6 inhibitors:

Strong inhibitors:
bupropion (antidepressant, Wellbutrin, Zyban, Budeprion and Buproban)
fluoxetine (SSRI, Prozac)
paroxetine (antidepressant, Seroxat, Paxil) Continue reading


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Filed under breast cancer, CYP2D6, tamoxifen

Three months post-chemo & all’s right in the world

Just got back from my 3-month medical oncology checkup. My onc. was surprisingly accepting of the fact that I decided to take a short tamoxifen break while I’m finishing up rads. I was afraid he’d be mad, but he wasn’t at all. Whew. Not only that, he offered to do the CYP2D6 testing to see if I metabolize tamoxifen AND he offered to do hormone testing as well. Continue reading


Filed under breast cancer, chemo, CYP2D6, quality of life, radiation, recovery, tamoxifen, tests

tamoxifen holiday

I actually feel quite insane given what I rationally know to be helpful about tamoxifen (it increases my survival chances as much as chemo), but I seem to be deciding not to take it. A temporary drug holiday, until I’m recovered from rads. I’ve been beyond tired, what with a cold, rads fatigue and tamoxifen general yuckiness. And when I go to take that tamoxifen pill? You know how it is when you just aren’t interested in a certain food? Continue reading


Filed under breast cancer, CYP2D6, quality of life, radiation, tamoxifen

Wellbutrin & tamoxifen DON’T mix, revisited

I first started taking wellbutrin in mid-2006, because I had overwhelming fatigue. Go figure, I had cancer. (A fact which we wouldn’t discover until 8 months later, but enough about that. For now.) I told my HMO at the time that I wasn’t depressed, I just felt very tired. So they of course put me on a series of anti-depressants, most of which did nothing, until we tried wellbutrin, which can act as a stimulant. Even at very small doses, it helped.

Thanks to the heads up from forum members, I asked my doc. (the one who prescribes wellbutrin, not my oncologist) about the info. I’d read on wellbutrin inhibiting tamoxifen.

She looked it up, and indeed there is a “cautionary” warning about its interaction with CYP2D6-metabolized drugs such as tamoxifen. It’s not a black-box warning, and it’s even not a strong warning as it doesn’t require monitoring. But still, she said it does compete with tamoxifen for metabolizing, so, since tamoxifen has such an important role in protecting me from cancer right now, her advice was to “Stop the wellbutrin. Now.” Continue reading


Filed under breast cancer, CYP2D6, tamoxifen

Metabolizing tamoxifen

What an interesting time we live in. Turns out that there are specific genes that affect enzymes that metabolize drugs. And some drugs inhibit the enzymes. This is important for women taking tamoxifen, because if it’s not metabolized well then it has less protective value. For me, tamoxifen is supposed to increase my survival chances just as much as chemo did. So metabolizing it well seems pretty important. Continue reading

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Filed under breast cancer, CYP2D6, tamoxifen, tests