When do side effects of anastrozole begin?

I have no argument with "trying it," but I think prospective patients should be aware that, often, the oncologist is NOT going to give an accurate idea of the side effects that could occur. Mi ne did admit that ANY of my many side effects were connected to the toxic pills, saying things like, "You're just old." It is logical to say, "Well, I'll try it and see." HOWEVER, I tried it and it crippled me and now I have liver issues that stem from "something you took that your liver didn't like." It's been almost 3 years since my tumor was found on Dec. 7, 2021. I regret not knowing how toxic A.I. pills would be to someone like me with severe osteoarthritis and damaged joints from both bicycling and volleyball accidents. After all, I had been in a nationwide study (MOST) of osteoarthritic joints for nearly 20 years, so a good oncologist might have taken that into account and suggested Tamoxifen, which doesn't attack bone density, but mine was too busy never showing up for any appointments and playing God. I also regret never having been told the truth about dense breasts, which started this whole saga back in 2018 when I was called back for my first (of 3) stereotactic biopsy. I suggest that anyone who HAS dense breasts (or knows anyone with the condition) check out this site:https://mydensitymatters.org/programs/my-story-matters/

When I actually began to research the 3 drugs they promote for adjuvant therapy, one oncologist said that Laetrozole and Anastrozole were "kissing cousins." Exemestane, however, is slightly different in its make-up and I would have been better off starting off with it, if ANY of them were appropriate. My current Texas oncologist says that, with my 20-year history in the MOST study and my damaged left knee and elbow (bicycling accident & volleyball dislocation) I was a poor candidate for any of the A.I. drugs, because they are designed to stomp out the estrogen in your body, and estrogen is essential for the pain-free functioning of our joints. Tamoxifen, on the other hand, a "blocker" drug, might have worked, but, of course, has horrible side effects such as endometrial cancer and the development of blood clots that can lead to heart attacks and strokes. Laetrozole is usually given to women in the U.K. and Europe first, because it has a slightly higher % of efficacy in trials. Anastrozole is the drug of choice for the average b.c. patient and Exemestane is not because Exemestane is more expensive. I actually went in and asked the pharmacist for the comparison prices, and it was definitely the more expensive drug, but one that had a chance of being less debilitating for the average user---but not for me. Every single visit I had as one of about 3,000 patients in the MOST study they did an MRI of my damaged left knee and X-rayed my other joints, and yet my oncologist blithely put me on Anastrozole less than a week out of surgery at a time when I was also fighting a seroma infection with 500 mg. of Cephalexan taken every 4 hours for weeks. He dismissed any stories of side effects, IN WRITING, saying, "The only side effect from taking Anastrozole is a little bit of achiness in your hands and fingers when you first wake up, and that goes away when you quit taking it." That is so wrong that I can't even tell you the distance between reality and wishful thinking on his part. When my knee actually blew out and put me in a wheelchair, he dismissed that side effect as "You're just old" and he only showed up in person for 2 appointment in 8 months. His "minions" (look-alike blonde P.A. girls with names like "Heather") always fielded my patient portal inquiries about ordering me a ki67, suggested BY MY SURGEON, with the response, "You would need to talk to the doctor face-to-face for that" and, of course, the doctor was seldom face-to-face with me from meeting #1 (Feb. 1, 2022) until October 3, 2022, the day we finally met to discuss my first post-operative mammogram (which I had to be wheeled to in a wheelchair). When I attempted to describe the hell I had been experiencing since the finding of my 11 mm. tumor on Dec. 7, 2021 and to ask him to please order the ki67 so that I would have some idea of the % of a recurrence (he refused to order an oncotype for me, saying, "You don't need one"), he said, "I won't order that for you. You'll have to get someone else" and get up and walked out. He had also gotten up and walked out of the prior meeting when I had a list of side effects that included teariness, mood swings, brain fog, excruciating back and joint pain, blurry vision and vivid violent nightmares that accompanied ongoing insomnia. That time he said, "Don't take it then" and got up and left. He was big on walking out with no discussion of any alternative plans of action or medications and I was never given anything for a truly huge amount of pain that I was experiencing. If I had not taken myself to the joint pain clinic in Chicago after my knee blew out on 9/15/2022 I would never have received anything for pain and, even then, I had only 15 Tramadol pills (50 mg.) for pain that kept me wheelchair bound from September 15, 2022 until March of 2023. I would love to report these side effects to the appropriate agency and ask the very logical question, "Why would they be prescribed to a woman who was in a clinical trial for osteoarthritis that was severe for 20 years?" I wrote a letter to the hospital where my dismissive oncologist was employed. They never answered it in any way, but I recently received a notification that Dr. Constantinou will be retiring soon. There are no better ones available in my geographic area, apparently, as, when I asked in Iowa City of the oncologist assigned me at the University of Iowa Hospitals and Clinics who would be a "good" oncologist in the Quad Cities, since mine was not attentive or compassionate or open to even listening to his patients, his response was, "Why do you think all of the patients in the Quad Cities come here?" (which, by the way, is a 3 hour round trip drive up and back).

@einnoc, I'm sorry that you belong to the unfortunate group of patients for whom aromatase inhibitors caused side effects that were/are limiting your quality of life. Thank goodness you advocated for yourself and got the testing and trials that you did. Good for you.

I'd like to also state for @meomurian and other members who may be about to start medication with an aromatase inibitor (AI), like anastrozole (Arimidex), exemestane (Aromasin) and letrozole (Femara). or a selective estrogen receptor modulator (SERM). like Tamoxifen, that not everyone experiences side effects.

Some people experience no side effects or few side effects. Others experience side effects that descrease or increase over time.

Bottom line: Everyone is different!

Reading messages on a forum like this one can lead to the misperception that the majority of people experience side effects. That is understandable. People who are coping with side effects seek help from others for solutions and support.

As moderator (and sometimes "the annoying person" :-), I think it's important to discuss options with your doctor. As per the community guidelines,
https://connect.mayoclinic.org/blog/about-connect/tab/community-guidelines/
All information shared by members on the Mayo Clinic Connect, such as messages, images, advice, URLs, and any other material, is for informational and support purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding your health. Never disregard professional medical advice or delay in seeking it because of something you have read on the community."

@colleenyoung : Thank you for pointing out that people's reactions and side effects vary greatly. I've been on Letrozole for over 3 years without significant problems. From time to time I have joint pain in my hips, and tight muscles, but that could just as easily come from simply overdoing things (particularly yard work). I've still not resigned myself to act my age (75), which is mostly good, but sometimes I pay for it.
Anyway, I am lucky to have had 2 excellent oncologists (first one moved away), always ready to listen to concerns, and to be very specific in answering any questions I have.

I'm 76 and have'nt had lumpectomy yet. Been taking Anastrozole for 2 months. I get a few hot flashes a day that are tolerable. Diet can lessen them,like cutting caffeine and alcohol. I take mine at 4 every day. Some aches and pains in the morning that are only slightly worse than before the meds.,but they subsides and I move .

I just want to add to the discussion as I saw my oncologist today. Two years ago she thought I had 1-2 years to live, and responded honestly when I asked. Right now I feel completely fine. I take letrozole, and today she indicated that it was what was keeping me alive. I had a lumpectomy and radiation for a rare tumor. (Little info on how it behaves and no established standard of care). No chemo because of co-morbidities and personal choice. I have zero side effects from the letrozole. I'm grateful for the drug. Many people have bad side effects, but many do not.

I am taking Anastrozole and started having severe anxiety, which I have never had in my life. I’m 70. Sleepy to but I started taking it at night, so that worked. A bit achy but not bad. It’s the anxiety! I spoke with the Oncologist and she felt I should stay on it since the other choice would be probably cancer again. My breast cancer by the way was so small biopsy got it all, no cells seen after the lumpectomy, no .lump to get but better safe, I get that. I would like to just get off it but she acted like it was a death sentence to make that decision. But I want a better quality of life, not taking yet another medication to deal with anxiety for 7 years. I don’t know what I’m asking exactly, just wondering if anyone else is facing this and what you’re doing.

If it was me, I'd try and get more information. Is the oncologist saying there is 100% chance of recurrence and/or spread without the anastrozole? If so, what are the odds with it? There are several kinds of aromatase inhibitors, and another one might work better for you. The choice should not be between years of anxiety and death sentence. This might be time to get a second opinion, or at least explore other similar drugs. Can you consider getting more information?

I started getting a lot of anxiety actually before I started the anastrazole, I was in radiation and I had already had my surgeries, and 6 months of chemo, it kind of hit me all at once. I did go on Zoloft lowest dose. I wasn’t excited about another drug but my oncologist explained that a cancer diagnosis comes with PTSD, especially when you have all of these hard treatments. I wasn’t excited about taking a lot to keep myself alive, why feel bad about taking something to make my quality of life better. I decided to give it a try and I am grateful that I did. The anxiety did not increase further with the anastrazole but I was already taking the Zoloft.
Did your doctor run the test on your cells that determines your risk with and without AI?

The Oncolist said I had a 20% chance of not getting cancer again. Or a 4% if I didn’t continue on the drug. I think it offended her I was questioning this drug. Which made me think I needed a different doctor. I wasn’t challenging her I wanted a discussion , I was asking questions about it. I’m thinking to ask for a different inhibitor and give her another shot. And see what happens. Our doctors need to be part of a team on ridding us of cancer not the only word in the discussion, not much of a discussion. And yes we always need more information!