Unable to tolerate tamoxifen.

To sk06 - Thank you so much for taking the time to respond and answer my questions! I really appreciate your sharing, especially since this is the next decision (really the only one I'll have to make regarding my treatment - since lumpectomy, radiation, and chemo were just a given). Gosh, I am so sorry that you had to go through this starting at 34, that is so young and amazing that you caught it. It seems as though the side effects are all over the place for different people, and unless there is some discriminating factor, I'm just going to have to pick something and start from there, and hope my MO is patient enough to find something that's tolerable.
Earlier in this thread, I mentioned that I suspected that I may have a CYP2D6 gene defect that would effect my ability to metabolize tamoxifen - so would have been taking it, and it wouldn't be working. The CYP2D6 enzyme breaks down as many as 25% of all prescription medication. So any variations could lead to being under or overdosed. So perhaps you were an ultra metabolizer and getting too much of the medication?

Does anyone know why some people are on the 5 year plan versus some on the 10 year? Does it have something to do with whether or not you've had chemo? Only 5 years have been mentioned in my case thank goodness, just wondering though.

I read there were 3 SERMS: tamoxifen, Evista, Fareston. I've read that someone was on Fareston. Anyone on Evista?

To sk06 - I had also come to some assumption similar to what your nurse had said regarding the AI's, as that same logic probably applies to how severe my hot flashes were from the chemo effecting my ovaries, but now luckily, I have a respite from chemo SE. However, in your case if age had been the driving factor in your reactions, then it doesn't make sense that you're able to tolerate lupron over tamoxifen. Tamoxifen gives you menopause symptoms but doesn't actually put you in menopause, but ovarian supression actually does?

"Ultra-metabolizers who have gene amplification at CYP2D6 will hyperconvert tamoxifen to the potent metabolite endoxifen, and will typically find tamoxifen intolerable. In theory they could pursue dose titration, but given limits on pill size and availability of good alternatives, will generally switch to AI's."

do this thread is older, but made me feel better about my tamoxifen experience. I had a massive headache from the day I started until after I stopped it, nothing helped the headache, it was awful, then I started having nightmares... That's when I called my doc. He said stop taking it now. I got a one month med vacation and just started Evista. So far so good, third day only a mild headache and mild nausea plus a little tired, but I imagine theses will get better once my body gets used to it. I am premenopausal and he told me this is really my only other option, so I hope I tolerate it.

I don't see much about Evista, anywhere, it must not be used much because they seem to give everyone tamoxifen.

Bonus is it helps strengthen bones.

Good luck to you