Lower Dose of Tamoxifen?

Options

Hello all,

I'm six months into 20mg of Tamoxifen. My side effects are reasonably manageable and I'll live with them if I have to - hot flashes and a new belly no matter how little I eat. My question is if anyone has reduced their dose to 5mg? There is a new study that came out in December 2018 done in Italy that showed that all of the benefits of Tamoxifen and none of the side effects were possible at 5mg. Does anyone know if Italian women are being prescribed 5mg at this point? I'm strongly considering this but would like to know your opinions.

Comments

  • DeeDeeT
    DeeDeeT Member Posts: 76
    edited March 2019

    What an interesting study! This is something that I have been thinking about, even though I haven't reduced my dose. In fact, my oncologist just bumped me on up to the full 20 mg dose. He had me take 10 mg first, so my body could adjust. I have been wondering why 20mg is the standard dose, no matter the size of the patient. I'm 5'2" and weigh around 112 pounds. But my dose is the same as someone who would be 5'10" 220 lbs. We adjust other meds for weight. This doesn't make sense to me and I forgot to ask my doctor about it last time. I think it would be wonderful to take a lower dose. But, of course, I don't want those the benefit of taking tamoxifen in the first place.


  • Falconer
    Falconer Member Posts: 1,192
    edited March 2019

    I also asked my MO this same question- why am I taking 20 mg when I am 5’3” and weigh 120? Of course, a year later I am still 5’3” but now weigh 129, no matter how little I eat and how much exercise I get- of course running is nearly impossible thanks to the leg cramps! So I’d love to share a link to this study with my MO. Can you post it Rachel? Thanks for sharing.

  • Rah2464
    Rah2464 Member Posts: 1,647
    edited March 2019

    I have taken a test to determine how my body metabolizes Tamoxifen. Before I consider looking at a lower dose I want to understand how much my body utilizes the medicine. I feel the 20mg may be too much given my BMI (about 17.8) - but who knows what the mechanism truly is. I don't know if your amount of estrogen correlates to your weight - but I am guessing it doesn't completely because some comes from your ovaries and some from fatty tissue. So I need to understand the way the Tamoxifen attaches itself and modifies the estrogen. I wish the studies included information on BMI and some type of estrogen marker to provide more clarity.

  • rachelcarter35
    rachelcarter35 Member Posts: 368
    edited March 2019

    I messaged my oncologist asking about the Italian study and asking what he thought about at least halving it to 10 mgs. He said he wouldn't recommend it and that that study was on women who had not already gotten breast cancer. I'm so confused. If I cut back perhaps I'd be fine and for sure would have less SEs but what if I have reoccurrence down the road. Could I forgive myself? Rah2464 keep us posted. This sounds interesting.

  • Rah2464
    Rah2464 Member Posts: 1,647
    edited March 2019

    Rachelcarter - I posted this on another thread, but my genetic test came back indicating I am a moderately poor to poor metabolizer of Tamoxifen. So here I go down another road. I am not sure what this means for me. Does it mean that I have been taking and metabolizing what is effectively say a 5 mg dose (vs pill is 20 mg) then for the last 8 months? Who knows. But I am sure my ONC and I will be going over the full test results and discussing moving to an AI. I was on Tamox because I am still (at 55) peri menopausal and have osteopenia. Oh well. Thank goodness I have been exceedingly careful not to take anything that is a known dampener of Tamoxifen action. I haven't even taken anything for the hot flashes, just tried acupuncture and a good fan.

    If you do decide to try a lower dosing at some point, please test to understand how you metabolize the drug. I think you want to know going in what the risks might be.

Categories