Femara insert: 20% dose is effective

windingshores

When I started Femara a couple of years ago, I read the insert that comes with the drug, which cites studies that say that 0.5mg effectively reduces estrogen to undetectable levels.

Does anyone know why the drug as manufactured is at 2.5mg?

If 0.5, 1.0, and 2.5 mg all are effective, why was 2.5 chosen as a standard dose?

Are doctors aware of these studies?

Is there a potential difference in side effects at the lower dose?

I asked my oncologist and she said it was okay to split my pills so I will be getting 1.25mg, still more than twice that 0.5 but half the standard dose. The pharmacist said okay to split too.

For my first year, I had joint pains that I addressed with exercise. I found that as long as I exercised 45 minutes at a time, the medication was pretty tolerable. At the end of my second year, I feel more fatigued, and have a few other side effects that bother me. So this dosage question loomed larger, particularly if a lower dose has less impact.

But undetectable levels of estrogen would have the same side effects regardless of dose, right? I mean other than saving money, will reducing my dose actually reduce side effects? It seems to me that a higher level of estrogen would be needed to reduce side effects- and that would feed cancer.

I am interested in why the dose is 2.5mg and whether cutting it in half will indeed help with side effects. It's scary to reduce the dose!

I welcome any and all info from other or from your MD's. Thanks!!

dtad

Hi there. That's a great question. It also brings me to the point again about why are estrogen levels are not checked regularly. Why the guessing game? Why are we waiting to see if we have a recurrence to know if anti hormone treatment is working? IMO a big part of it is that most MOs know very little about female hormones. I feel its a huge gap in our treatment. Good luck to all...

windingshores

I posted about this in another thread. I just want to make clear that no one should reduce their dose based on anything I post I am asking questions only, and have not yet reduced my own dose. Someone on the other thread said things are more complicated than just estrogen levels, and I would like to know more. The higher dose may accomplish things we don't know about.

Another concern is that Femara does not seem to have as much of an effect on distant recurrence as local, breast and contralateral breast recurrence. Many of us have had BMX's. My oncologist said that after 5 years the benefit is low, without any breasts, so I am wondering how much of a benefit there is earlier than 5 years. Again, I am NOT suggesting anyone go off Femara. But I am asking my oncologist more questions because there are things I don't understand.

I was a bit of a Polyanna about side effects. For me they are worse after two years. Joint pain I can handle but fatigue is harder. That said, I still have kids in mid-20's and would suffer any side effect to be around longer for them- IF that is what these meds help me do!