Are lower doses of Tamoxifen just as effective?
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Sher - Tam does have a long half-life.0
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That's what I thought. So this is just my thinking, and a few others I have had look at the studies, but is 20mg a day overkill? Is it still in you, protecting you while you're taking another pill? Are they just guessing that it's a good number and it's not worth it to find out if it's not anyway.
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I love love love that Sherbear's doctor told her she could go down to 10 mg if she was having lots of problems !!!!! That should make you feel better Sherbear even if you don't have to do it.
She does know something for sure but believe me she'll never tell. There probably have been limited studies that show effective results in some. But I'm sure not enough that they could make it public knowledge.
Catbird
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lol 0
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Sher - I can't find the source yet for the half-life of tam so it could be the endoxifen that lasts a long time, I'll look again tonight. I think its basically the same, since tam is metabolized into endox.0
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Sherbear,
So glad to hear that your onc would support you going to a lower dose if you have problems at 20 mg. And encouraged to hear about the clinical trial that Neece is in. There just has to be a better answer than it has to be 20 mg.
Deb
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Sher - here is some info from
Studies confirm that tamoxifen is 98% bound to serum albumin which ultimately creates a long biological half-life (plasma half-life 7 days). A single oral dose of 10 mg tamoxifen (half the daily dose) produces peak serum levels of 20-30 ng of tamoxifen/ml within 3-6 h but it must be stressed that patient variation is very large. Nevertheless, continuous therapy with either 10 mg bid or 20 mg bid produces steady state levels within 4 weeks. Blood levels of tamoxifen can average around 150 ng/ml for 10 mg tamoxifen bid and 300 ng/ml for 20 mg tamoxifen bid. A strategy of using loading doses and to elevate blood levels rapidly has not produced any therapeutic benefit.
Overall, the results from the metabolic studies with tamoxifen during the 1970s and 1980s did not help clinicians to use tamoxifen more effectively. The structures of metabolites were in fact used as leads to create new molecules for clinical development
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I think tamoxifen may be used as an anti-estrogen by body builders - anyone else heard that?
Also, does tamoxifen act like an estrogen in tissues other than breast tissue? Thanks
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This is exciting stuff! I am seeing a plethora of doctors and will definitely be bringing this up to see what they say!
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Hi All,
Some place back in my feathered brain (brain on the Big T)..... I recall reading about Tamoxifen and body building, but it was of no interest to me so I'm blank on what it was about.
This is great that we are delving into it. So many medications are given by a person's size or their particular severity of the disease, etc., that it does make you question the dosage.
Catbird
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I just want to add this in - even though I add it to the discussion with disappointment. I went to a 2nd mo today who also recommended tamoxifen for me. When asked about taking a lower dose than 20 the response was it was proven that it did not work well- 20 is the dose. Since it was my 1st visit I did not have an argument regarding this since I did seek out this physician based on recommendations of him being a breast cancer specialist. Just sharing- take care.
Chocolate
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Thanks Chocolate, I appreciate you adding to this. I'm going to be starting Tamox in a few days, I'm just waiting to hear back from my ND about when I should take my supplements as well, but I did want to say that I'll be taking trying out the 20mg full dose. I'm usually pretty tolerant with drugs, not that I take a lot of them, but the past year has definitely been full of them
and I want to test it out. Am hopeful that I won't have complications on it, but if I do, I'm glad that I'll be monitored and can move my dose down if needed. I am still hopeful that more research will be done into this though, as many women seem to suffer needless effects from such a powerful drug.
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I went up to the 20mg today as well.
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Yeah, I don't want to chance it and play around with it too much, even if my onc did give me some leeway. I'm not a doctor, so I'm not going to self-medicate with my own 'protocol' or anything like that, but I still want to keep on top of anything related to this subject.
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We are all in the same boat! My doctor gave me the same spiel. I'll be starting Tamox when I am done with radiation (early-mid July). In the meantime, I will be researching alternative complementary therapies that will hopefully make it more effective. If I have to put up with side effects, I want the stuff to WORK!
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Totally agree Sweetbean, I've done a lot changing life-style-wise to hopefully help out and I want the most from this drug as well so I'm hoping to complement it with things that will boost it's effectiveness and lower the risk and undesirable effects from it. Fingers crossed lol.
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I have been on 10mg. each day of Tamoxifen since last October. I am 70 and was very active until diagnosed. Originally they put me on Arimidex (no problems until about month 3 and then the side effects escalated until I quit at month 6). It caused horrible joint and muscle pain as well as tendinitis. I used to play tennis however that changed once the tendinitis developed. They took me off of Arimidex and put me on Aromasin.........only lasted two weeks because of side effects. The tendinitis did not totally resolve but it did get better off of Arimidex. So finally they decided that Tamoxifen might work. I tried the 20mg. for about three weeks and again the side effects were not anything I wanted to endure. It is probably my age that helped me decided, after reading studies on low dose tamoxifen, that I would be happy to go to 10mg because I did want some quality of life and the 20mg did not provide that for me. I showed my onc the studies and he responded with "Well, 10 mg is better than none." I just had another breast MRI and fortunately it was clear. I know that I am taking a risk having made this decision but I did modify my eating to grass-fed/pastured meats and all organic veggies and fruit. I take supplements and only hope that I am not making the stupidest decision of my life. I find this thread very interesting. Good luck and health to all of us regardless of what choices we make.
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My onc spent a lot of time with me on this subject. I have other medical issues that make the drug very hard to take. My SEs are rough.
There have been studies on lower doses, so don't accept the answer that they have not been done. I don't think any have been done in the US, which is interesting. Why the heck not?!
The study my onc talked about was done with a small group, in Brazil, I think. These women took 10 mg a day. There was in fact an improvement in mortality/recurrence rates, but probably not as high as benefits received from higher doses.
If you are one who cannot tolerate the drug, it may be worth trying to do 10mg. Your onc will be the best one to talk to.
In cas you are wondering what my SEs are, here you go: tremors/palsy, poor coordination, fatigue, headaches, lots of uterine fibroids. This may give you a benchmark to evaluate your own SEs. I can say that in time, a lot of the bad stuff does go away, so you might try to hang in there for a while before you throw in the towel.
The bottom line is each of us has to decide if we're being whimpy, or if we are just one of those women who cannot take the drug. Tough call. Best of luck to each of you.
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I found this conversation just before I went to see my ONC to tell him that I had stopped taking Tamoxifen so I wanted to let you all know about my experience. I was diagnosed with DCIS in the left breast in June 2008, had a partial masectomy and 6 weeks of radiation therapy. I took 20mg of tamo for 2 years and for most of that time had very mild side effects. After 1 1/2 yrs the side effects got worse. After my period, I had almost constant discharge, requiring me t to wear a pad for 3 weeks out of the month. I had painful leg cramps that woke me nightly, extreme fatigue (after my kids went to school I would often go back to bed and sometimes fell asleep at my desk at work). I also felt nauseous in the morning, much like mormimg sickness. When I described these symptoms to my ONC he dismissed most of them as not attributable to the tamo, especially since I had been taking it for 18 months already.
I decided to stop at the 2 year mark, which happened to be New Years Day. Within 2 months all of those side effects disappeared. I felt like my old self again. Of course then I had all kinds of doubts and fears about the cancer coming back. My MRI 2 weesk ago showed no sign of cancer. I have my next mammo coming up in a couple of weeks. My ONC agreed to prescribe a lower dose of tamo for me, although he said he had never done that and he had no evidence that it would in fact be "better than nothing." It is the standard of care until proven otherwise. He also said that the reason there have been no clinical trails of the effectiveness of lower doses is because this drug has gone generic and no one stands to make any money from it.
I have decided to take my chances with the lower dose. After 3 weeks, so far so good. By the way, I am 5' 1" and weigh 115 lbs,-- I just don't think my body could tolerate that higher dose. The survival rate for someone with my type of slow growing DCIS is no better with or without the tamo. If it comes back, then I will deal with it but I could not take another 3 years of feeling so crappy. As my ONC said to me, "YOU are the boss!" Good luck to all of you. Don't be afraid to advocate for yourselves!
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Bump....any takers out there?
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I am bumping this thread in the hopes that others are also interested in this topic. I have just been taking 10 mg Tamoxifen on my own instead of 20 mg because I was having issues with cysts on my ovaries and irregular periods due to the Tamoxifen. I see my Oncologist in Oct. so am researching this lower dose info prior to meeting up with him to see if it is as effective.
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hipz, I had put myself on 10mg without checking with onc first. I did get her blessing however. She told me that there have been no studies done as to whether 50% of the dose is as effective as 100%, but that there have been studies showing that 70% of the dose is effective. I didn't read the study that's posted at the top of this page. I know that it must have been working (or doing something) because I got pancreatitis while on the 10mg dose.
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The "studies" have been mentioned on other threads also. I think it's important to make sure the study is relevant to your situation. If the study was done on prevention or DCIS patients & you have IDC, it's may not be relevant to yout. If it looked at "biomarkers", that's not the same as disease free survival. It may be true, that 10mg is better than none. Or perhaps it will be enough to make your cancer resistant(like antibiotics/bacteria). OK, that's just my thought, no studies to back it up.
I had my MOs blessing, he even suggested it, to reduce my dose to 10mg. I did so for about 6 weeks. Unfortunately my side effects weren't helped much by this. I went back to 20mg & continue to tuff it out. Right now my biggest issues are GYN. But those leg cramps can be fierce!
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coraleliz, very good point!!
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Thanks ladies! I def. plan to ask my Oncologost about it when we meet next.
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I have been on Tamoxifen for 6 months. I lowered my dose to 10mg on my own 2-1/2 months ago after my Onc told me that the dose is higher than needed and not what is minimally effective. My side effects weren't horrible, but they were there and I worry about blood clots other cancers etc. Tamoxifen at 20mg stopped my period completely (I was very regular every 30 days just prior). Since I have been half dose for 2 1/2 months most side effects are minimized, but I still do not have a period, have some genral fatigue, occasional hot flash and I still have joint pains in my feet. (Which I did not have before Tamoxifen). BUT I feel so much better now overall -did not realize how much the 20mg had affected me. For me, the 10mg dose is doable for the 5 years
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EnElle,
I've been posting on other threads with a suggestion for consideration by those taking tamoxifen, and will post it again here for you as well.
try googling "tamoxifen karolinska institute breast density"
They are doing research to try to determine whether reduction in breast density while on tamoxifen is a reliable indicator of the successful action of the drug, and to figure out how best to measure breast density. Logically, this could help quite a lot if this research holds up, since it could allow patients to either take the drug for a shorter period of time, take a lower dose of it, or maybe change to another drug if they happen to develop tamoxifen resistance.
In my own situation, I had a mammo after completing CAFx6 and radiation and my breasts were stlil very dense. Within 3 months of starting tamoxifen, the density had entirely disappeared. Because resistance to tamoxifen develops for about 1/3 of those who happen to be HER2 positive (which my tumor was), after taking the drug for 1 year at full dose and 3/4 year at half dose, I chose not to continue it. I chose not to switch to any AI. I have never had Herceptin, either. I have never recurred.
Researchers outside the USA sometimes ask questions that aren't being researched in the USA. I'm grateful that they do.
A.A.
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Thanks EnElle! I have been taking the 10 mg on my own for about 2 months and my periods are back to normal. I also take the supplement DIM as an added bonus. I feel better since I reduced to 10 mg. I go for another pelvic ultrasound on Monday so I will see if it has also decreased the ovarian cysts I was getting from the Tamoxifen and my bad estrogens. Glad there are others taking the 10 mg dose. I had a double mastectomy so have little to breast tissue left so basically feel the 10 mg should be more than sufficient for the little tissue I have and also to ward off distant tumors. When I only had a lumpectomy 12 years ago I would not have felt as comfortable going down to 10 mg on my own but I am in a different situation today.
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p.s. I am also taking a baby asprin daily to help with absorption and blood clots - there are some studies out there about baby asprin and Tamoxifen and my Oncologist said I was fine to add the baby asprin.
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I'm so glad this topic is being discussed. I'm almost midway through radiation, tolerating it pretty well so far with just fatigue and mild burning.
It's the Tamoxifen/AI prospect that has me on the ropes in the middle of the night. Of course I don't want a recurrence (this also terrifies me), but the reports of side effects and the extended nature of the therapy brings up serious quality of life questions for me. I'm not physically small, but my history with medications has always been that prescribed 'normal' doses are too much for me, less works better.
I will probably start with the 'standard of care' when the time comes, but I plan to print out the studies mentioned and bring them to my next visit w/ my oncologist and hope for a medical blessing if I ask to lower the dose.
I'd love to hear more from those of you contemplating or implementing this plan.
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