Anastrozole: Any studies on its side affects?

There are numerous discussions in Breast Cancer about Anastrozole, including side effects. Put "anastrozole" into the search (icon of magnifying glass) and you will find a great deal, which may answer your questions. Of course you may get info here, too, but existing discussions may be of additional use to you.

I'm very sorry to hear about these difficult side effects. There are numerous discussions in Breast Cancer about Anastrozole, including side effects. Put "anastrozole" into the search (icon of magnifying glass) and you will find a great deal, which may answer your questions. Of course you may get info here, too. Also, a different aromatase inhibitor might work better for you--worth asking your doctor.

@mir123 I too would like to see more research as to what factors make some people more prone to severe side effects. Are these issues dictated by lifestyle, genetics, previous hormonal reactions ( eg post natal depression etc).?
It might enable better prediction of patients who will be more likely to be affect and possibly decline or default treatment. I also agree that t.here seems to be a fair level of consistency in the descriptions and responses we see on this site. We can’t all be ‘ imagining it’!

Hi there. I am on anastrozole for about 4 years now. I had estrogen positive (high) 90%. Per my blood work. I was 58 at the time and post menopause. Went into menopause at age 38. No surgery or medication just happened. I have heard that if your levels are high most people don’t have lots of side effects. Anastrozole lowers your estrogen so if you have low estrogen going into the treatment. I would ask your doctor about it. I have mild effects. Low sex drive dry vajay vajay. And fatigue after taking it. I take my pill after dinner because I am still working. Hope this helps
Remember we can strong women and together we can fight this together. Stay strong and steady!!!

Hopefully someday soon there will be better treatment options for breast cancer than the AI's & tamoxifen. I take a half-dose of Tam (10mg) & am doing ok so far. I'll echo what many people here say, that it's critical to advocate for yourself. Have you asked your doctor to prescribe a different drug? A new medicine might be better for you. There's a lot of trial & error, unfortunately. I hope you find a good fit! Hang in there.

I had a colonoscopy ;last week and 2 days later started having horrible leg cramps. The same type I had after the first month on Anastrazole. I could not walk comfortably for 5 days, particularly up and down steps. My muscles were seized up. I went in for ultrasounds and bloodwork to rule out a blood clots. Now they think I may be having some stenosis. This could be because I am 74 and have had broken knee surgery 2 times, or due to the medicines. I have had a host of new ailments since I begin this magic pill. I had taken a 10 day holiday before the routine colonoscopy just to see if I felt better from the GERDS, causing vocal cord dysfunction, constipation, and before that infectious Diverticulosis, urgencies to pee, and before that an unusual amount of bee stings as bees suddenly have taken an interest in me, etc. The fatigue, feelings of anxiety, pounding heart, sometimes irregular heart beat, vision issues, Trigger fingers, stiffness, difficulty sleeping, you name it...I have had since taking this med.
Today I am starting Tamoxifen. AI says it may be ok to switch back and forth every 6 months to avoid some of these build ups. I am just hopeful I can tolerate a med for the remainder ( 3.25 years) needed to complete a 5 year program. April marks my 2.5 years since surgery, I completed 5 days radiation, 13 chemos, 25 immunotherapy all in 2024. I suppose some of these health issues could stem from all of those treatments. But I did begin to feel much better after 10 days off of Anastrazole. The most important thing my GP has shared is to drink a min of 60 oz and preferably 90 oz of water each day to flush all of this mess out of our bodies. And to do gentle but consistent exercise. I looked at the predict site. It seems to be saying that each treatment only adds a 1% value to longevity, if I am reading this correctly. So I am unclear of the value. I was ER+91, PR+1, HER2+, ILC, with grade 1A, no node involvement and a clear margin surgery. Look at supplementing with DIM and eat a cruciferous vegetable every day to flush out the synthetic estrogens we get from the environment.
( GMO's, Plastics, Pesticides) I have posted some of this before and apologize for those who have read some of this before. It seems something new crops up every week or two. And while each is so annoying, there are measures to help manage the discomforts.
Best wishes to all.

I agree with you- I want better options I dont want to hear you can take this or that MORE drugs to work with side effects OR try acupuncture?????there definitely 💯 should have come up with more natural alternatives it’s 2026!!

I went through the same type of pain response to Anastrazole. It wasn’t a constant low level whole body thing - though there was persistent lower back and hip discomfort. But it wasn’t a constant like today someone stuck a knife into my left ankle for several hours then tomorrow they would move it to the right hip. Trouble with both hands, primarily thumbs making it almost impossible to hold things some days. There were other, sometimes fleeting, side effects like nausea, dizziness but that stabbing pain was a problem. After 9 months, oncologist commented “you shouldn’t have to live in pain” and took me off. Of course everything has side effects and not sure if exemestane is much better. No, not the stabbing pain but fatigue, insomnia, weight gain, weakness, tinnitus that weren’t present on Anastrazole and are more ongoing than brief episodes like before. My primary problem is that a lot of these are not recognized as side effects of the drug so there is no relief other than to try yet a different drug or just stop completely which I am considering.

You would think by now they could come up with an estrogen blocker without all the side effects. I'm sorry you're going through what you're going through.

Hi pmom3366, I had Anastrozole for 20 days only. It gave me terrible back pain I barely can walk. I quit. Now I am on Letrozole for 6 months, I was doing OK. But on 7th months I have feet edema and my Oncologist said that is nothing to do with letrozole. She wants me to see my PCP. I insisted that is her job to treat me and told her to google it. So she called and ordered U/S stat. to R/O DVT. I had it done immediately. The results is Negative luckily. Now she give me 14 days off the drug. I don't know what she will do the next. I might to try the same drug again. My question to you is that you have been suffered for 3 years. Why are you keeping taking it? Why not to try different AI. Pain is terrible to handle I feel so sorry for you. Because I have other medical issue that I need to take painkiller every day.