Monday, May 9, 2011

The Scoop on Aromatase Inhibitors

As I mentioned in earlier blogs, my doctor sentenced me to three years on Arimidex medication. I am not happy about this, so I pulled this article from the website, to give me more information on the good, bad and ugly of this medication. I would like to hear from other women currently taking aromatase inhibitors and how they are tolerating it. Let me know!

Aromatase inhibitors stop the production of estrogen in post-menopausal women. Aromatase inhibitors work by blocking the enzyme aromatase, which turns the hormone androgen into small amounts of estrogen in the body. This means that less estrogen is available to stimulate the growth of hormone-receptor-positive breast cancer cells.

Aromatase inhibitors can't stop the ovaries from making estrogen, so aromatase inhibitors only work in post-menopausal women.

There are three aromatase inhibitors:

Arimidex (chemical name: anastrozole)
Aromasin (chemical name: exemestane)
Femara (chemical name: letrozole)
Each is a pill, usually taken once a day. Arimidex is the only aromatase inhibitor available in generic form.

Benefits of aromatase inhibitors
A number of studies have compared aromatase inhibitors with tamoxifen to see which type of medicine was more effective in treating early-stage, hormone-receptor-positive breast cancer in post-menopausal women. Based on the results, most doctors recommend that after initial treatment (surgery and possibly chemotherapy and radiation therapy):

an aromatase inhibitor is the best hormonal therapy to start with. When treating early-stage, hormone-receptor-positive breast cancer, aromatase inhibitors have more benefits and fewer serious side effects than tamoxifen.
switching to an aromatase inhibitor after taking tamoxifen for 2 to 3 years (for a total of 5 years of hormonal therapy) offers more benefits than 5 years of tamoxifen.
taking an aromatase inhibitor for 5 years after taking tamoxifen for 5 years continues to reduce the risk of the cancer coming back, compared to no treatment after tamoxifen.
Side effects of aromatase inhibitors
Aromatase inhibitors tend to cause fewer serious side effects than tamoxifen, such as blood clots, stroke, and endometrial cancer. But aromatase inhibitors can cause more heart problems, more bone loss (osteoporosis), and more broken bones than tamoxifen, at least for the first few years of treatment. If you and your doctor are considering an aromatase inhibitor as part of your treatment plan, you may want to ask your doctor about having a bone density test to see if a bone strengthening medicine might be necessary while you're taking the aromatase inhibitor.

The most common side effects of aromatase inhibitors are joint stiffness or joint pain.

Joint pain from taking an aromatase inhibitor can be troubling. But a 2008 British study suggests that women who experienced joint pain while taking hormonal therapy medicine were less likely to have the breast cancer come back (recur). Knowing that this side effect might indicate a reduced risk of the cancer coming back may help some people stick with treatment despite the side effects.

If you're experiencing side effects from taking one aromatase inhibitor medicine, tell your doctor. You may be able to take a different medicine. Arimidex and Femara have similar chemical structures, while Aromasin has a different structure.


  1. I read your blog re aromatase inhibitors with interest. I have been on all 3 and settled on Arimidex because I seemed to have the least painful side effects on this one - the big plus is that it is cheaper (generic version). Still, in order to take an aromatase inhibitor I must also take an anti-inflammatory (for the joint pain), a prescription grade medication to offset the tummy problems I have by way of the anti-inflammatory med plus Actonel for bone density. Prior breast cancer I was diagnosed with osteopenia... post breast cancer they now term it as osteoporosis (in my back and one hip). I don't know how long I'll have to be on this regimen but I live for the day I can stop. I absolutely have not been able to lose weight while taking all these meds. Still, I'd rather be cancer free and obese than skinny and riddled with cancer. Sheesh... what a choice! I'm almost 2 years post treatment, i.e., surgery, chemo and radiation and am really just beginning to get my energy back in a manner that allows me to live a little. I'm handicapped a bit by the joint pain which really affects your mobility. I still feel a bit "less with it" as far short term memory. Has anyone else noticed this? I forget really simple things... and only remember them when I have a visual aid or a reminder. What is that all about after all this time? :) Chemobrain on steroids? Nope, not taking steroids anymore.
    I tried, reallt tried to stop the AI's... but my oncologist just kept working and working on me to keep on, keeping on. I'd really like to hear any other BC survivors comments about AIs.
    Also, are any of you having real issues with weight loss and/or with strong cravings for carbs and sweets (which I used to be able to pass on easily)? My best to all of you.. Take care and don't forget your mams/paps~

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