Anastrozole: Is it worth it?

@mogoodwin, welcome. Others have reported being able to tolerate exemestane after switching. How long have you been on exemestane? How are you doing on it?

@colleenyoung Do not start exemestane until the end of this month. Advised to take one month off between meds. Starting every other day for first month.

@mogoodwin
May I suggest that at the end of your first month, ask your onco for estradiol test to see if one every other day is good enough to lower estrogen to undetectable level (I think it’s less than 10). If you have no side effects and the level of estrogen is low enough, then ask if you can continue with that dose. Wish you all the best. Hugs.

@myoga That is a great idea. Thank you!

@lululinks Thank you for your input. I discovered that the pharmacy had changed brands and I could not tolerate the new brand. I am back on the original brand and I am finally feeling better. The pharmacist told me that they had another customer react the same way with the brand that was causing my problems. I hope that things are going well for you and thanks again.

I am so sorry for your side effects. I was surprised too about the manufacturers. Even when I brought the brand up to my oncologist and PCP, they really weren't aware of this type of issue. I hope that the Exemestane is working for you.

@debds Thank you!

I was put on Anastrazole initially. Had minor side effects that went away (nausea, headache, dizziness) after a couple weeks. Was about 4 months into it when the muscle and bone pain started. It would move constantly - today left ankle, tomorrow right hip - but it was sharp stabbing pain that got worse with time. At 10 months into it, oncologist said “you shouldn’t have to live in pain” and took me off. A month later started exemestane. Much better, different side effects. I do have fatigue (started about 5 months in) that often requires an afternoon nap to function or I just nod off in the middle of whatever I’m doing. Then about 2 months later the insomnia which doesn’t help the fatigue. My biggest problem is that they don’t recognize it as relating to the exemestane but keep trying to put me on antidepressants. He finally had me take a month off and things did start to improve but back on and will see him again next week.

Aromatase inhibitors have been around for 25 years with all their debilitating side effects. I find it infuriating that so many people write in to this forum and report that their oncologists refuse to acknowledge the pain and suffering they are experiencing are caused by these drugs. The side effects are well documented!
In December 2020 at the age of 70, I was prescribed 1 mg anastrozole every other day for 1 month. In January 2021, I began to take 1 mg every day. This dose of 1 mg is protocol. Drug companies determine the MTD - maximum tolerated dose. This dose is the same regardless of a patient's stage of cancer, age, weight, or preexisting conditions. Some studies have found that 1 size fits all when it comes to dosage is not appropriate. Older women metabolize drugs more slowly and often have more preexisting conditions. Why does a woman who weighs 120 need the same dose as someone who weighs much more, if estrogen is produced in our fat cells? Oncologists seldom discuss with their patients whether or not these drugs will improve their overall longevity. I was told that my breast cancer was stage 1 and my chance of recurrence would be 6%, if I took anastrozole and a 12% chance, if I didn't.
On February 11, 2021, I called my oncologist to report my MANY side effects. I was advised to stop taking the pills. At the next appointment, she dismissed all my side effects, except for my severe depression which she attributed to my concern over having breast cancer. She sent me to other doctors to determine the cause of my complaints. No other causes were found and the side effects all subsided in a rather short time after stopping anastrozole. The severe depression went away, in spite of the fact that the chance of recurrence is never 0%. I was strongly encouraged to take exemestane by another oncologist. He said that he could help me with the side effects, if I had any. I asked him what that meant. He said he could prescribe an anti-depressant, infusions for bone health if my osteopenia progressed to osteoporosis and medication for my daily headaches. When I asked about the potential side effects of the drugs to "treat" the potential side effects of exemestane, his response was, "Well, there's that." I opted not to take another AI. At age 71, I decided that quality of life was a priority. It will soon be 5 years, since I stopped taking anastrozole. I walk every day and fell well.
I realize that I am fortunate that my breast cancer was stage one and my chance of recurrence is relatively low. Each one of us has the right to make whatever decision is right for us. Try not to look back. I wish you all the best for the New Year.

@bloncape
I’m inclined to agree with you! Took letrozole for 7 months; fatigue was getting to me so just started anastrozole with surgery scheduled in March. When I was first diagnosed with ILC in June 2025 I was told I would need a mastectomy. I switched doctors to a well respected oncologist weed who immediately recommended taking AI to avoid (or so I thought) a mastectomy. Now told it could become a mastectomy depending on pathology report after lumpectomy. As I let that sink in…I’ve become apprehensive and almost angry that I’ve been fighting this rather large lump for 2+ years (after b ET ing told nothing to worry about—but feel a biopsy should have been done then since I had BC over 20 years before!). This certainly “plays with my head” at times and I’m angry that I didn’t just get mastectomy 7 months ago.