Exemestane side effects

Posted by brightlight66 @brightlight66, Sep 16, 2025

I've been on Exemestane for two weeks and have abdominal discomfort...gas, nausea, rumbling, diarrhea, etc.
Thinking of just getting off it as I can't imagine feeling this way for 5 years. Any other experiences out there? I was diagnosed with invasive lobular and already had surgery, chemo and radiation.
Thanks!

Interested in more discussions like this? Go to the Breast Cancer Support Group.

Profile picture for kal25 @kal25

I too have Gastro difficulties on Exemestane, taking it after my dinner meal has helped some. By 18 to 20 month, I had so many side effects on anastrozole I had to go off. These intermittent Gastro symptoms are so minor to the symptoms of fatigue, pain, dry eye, lichen, sclerosis, tendon problems, etc. on anastrozole. I think with all these medicines, you have to find one that is the lesser evil of the others for you and your body.

Jump to this post

@kal25 I am on Exemestane too, feel heart uncomfortable except fatigue. It seems anastrozole is less toxic in general and normally doctor gives first try.

REPLY

I switched from Letrazole to Exemestane. Now I just developed a long knot at my right ribcage and I think, don't know for sure, could it be from Exemestane? I've been on it for a month now and it's the only change I've made. Anyone else experiencing any weird or different side effects ?

REPLY
Profile picture for rose22 @rose22

I switched from Letrazole to Exemestane. Now I just developed a long knot at my right ribcage and I think, don't know for sure, could it be from Exemestane? I've been on it for a month now and it's the only change I've made. Anyone else experiencing any weird or different side effects ?

Jump to this post

@rose22 :

Hi! Rose:

My heart and prayers go out for you upon reading your post! I am so sorry for what you've been through in such a short time frame:(

Unfortunately, I am no expert and have never taken Exemestane yet, thus I can't offer any assistance on this matter. But please reach out to your physicians to be adequately checked to make sure that there's no underlining serious issues. Hopefully your care team will guide you step by step and resolve the issue effectively soon.

Praying hope and peace of mind for you, and wisdom and caring hearts for your care team, my friend! Wishing you a smooth and successful treatment ahead, for our thoughts and prayers be with you along the way!

REPLY
Profile picture for lifetraveler @lifetraveler

@rose22 :

Hi! Rose:

My heart and prayers go out for you upon reading your post! I am so sorry for what you've been through in such a short time frame:(

Unfortunately, I am no expert and have never taken Exemestane yet, thus I can't offer any assistance on this matter. But please reach out to your physicians to be adequately checked to make sure that there's no underlining serious issues. Hopefully your care team will guide you step by step and resolve the issue effectively soon.

Praying hope and peace of mind for you, and wisdom and caring hearts for your care team, my friend! Wishing you a smooth and successful treatment ahead, for our thoughts and prayers be with you along the way!

Jump to this post

@lifetraveler
Thank you so very much for your kind words.

REPLY
Profile picture for rose22 @rose22

I switched from Letrazole to Exemestane. Now I just developed a long knot at my right ribcage and I think, don't know for sure, could it be from Exemestane? I've been on it for a month now and it's the only change I've made. Anyone else experiencing any weird or different side effects ?

Jump to this post

@rose22 I switched a month ago as well. A few days ago I developed a large, hard knot/lump on the inside of my wrist. Feels just like the lump I had in my breast, but my oncologist dismissed it as having nothing to do with cancer. ?!

REPLY
Profile picture for briarrose @briarrose

Well there are other AI's to try which might not have the same side effects you are now experiencing.
But remember, ALL of the AI's have many, many side effects.
I am on anastrozole 1 mg. daily since June 2025. I have an annoying headache just about every day. And I am monitoring my blood pressure as it has increased (the systolic) despite 2 increased in my blood pressure medication. It's not at a danger zone right now...but it's consistently higher than it was before taking this drug.
My bone density at age 68 was normal. Now at age 70 and 3 months on this medication I have osteopenia in my left hip. Normal aging? Maybe. No one knows. But I will be monitored more frequently now. Plus I have ischemic heart disease and the combination of this health issue but the AI is not good at all. I can have a heart attack or stroke.
What to do? With invasive cancer (like me) I feel one needs to take their best shot to prevent a reoccurrence.
Of course, not all women feel this way. Some women are living in the moment and want quality of life.
But like everyone else, I don't want the cancer to return...and it most certainly can. I am between a rock and a hard place. But this was my decision. Weigh the pros and cons. And "maybe" your symptoms will resolve after a bit more time(??). All the best to you!

Jump to this post

@briarrose I too am between a rock and hard place, especially at my actual age of 85. I have led a very active lifestyle in leadership roles and very involved in activities. Now, I am cutting back on things. Picking and choosing what is most important to me. I was told the AI would age me and it sure has. Fatigue, hand problems, mood changes etc. The cancer was pretty aggressive so I feel I need to continue as long as I can on the drug. Just the last month or so I noticed I am losing a lot of hair again including eyebrows. Oh, darn. Well, we keep on keeping on. Staying busy helps as long as I can overcome the fatigue.
Wishing the best for all of us on this journey.

REPLY
Profile picture for ksue3 @ksue3

@briarrose I too am between a rock and hard place, especially at my actual age of 85. I have led a very active lifestyle in leadership roles and very involved in activities. Now, I am cutting back on things. Picking and choosing what is most important to me. I was told the AI would age me and it sure has. Fatigue, hand problems, mood changes etc. The cancer was pretty aggressive so I feel I need to continue as long as I can on the drug. Just the last month or so I noticed I am losing a lot of hair again including eyebrows. Oh, darn. Well, we keep on keeping on. Staying busy helps as long as I can overcome the fatigue.
Wishing the best for all of us on this journey.

Jump to this post

@ksue3 I’m interested when you say you were told AIs would age you. Your information giving was realistic and upfront to enable your decision making. I wish this was true for all of us. My experience is that the possible severity of side affects some people ( in reality quite a significant proportion!) may experience is underplayed ,and sadly in some cases by senior clinicians. I realise they do not want to influence people against consideration of these therapies, but this does not excuse lack of candour. ‘ You might get a bit of finger stiffness’ maybe ‘a few aches and pains’ etc - not realistic for those who find themselves in constant pain and with severely reduced mobility and life quality. Added to this I feel some people perceive ,on the back of such ‘ information’ that it is somehow their fault they have such pronounced symptoms. In a way this almost turns into victim blaming. A plea to clinicians please be honest!

REPLY

Interesting, I recently switch from Letrozole to Exemestane due to joint pain/stiffness. In reading your post, I realized that I have had some stomach "uncomfortableness" over the last few weeks and now thinking it might be the Exemestane. Other than that, I seem to be tolerating it and my pain/stiffness is subsiding.
Good luck to you!

REPLY
Profile picture for myoga @myoga

@kategiddyup
Discussion on using Claritin for bone pain was also mentioned in a different threat few years ago. What really interesting is the ASCO abstract found the link between using Loratadine and lower risk of cancer recurrence. It recommends further research but I could not find any update. I think we need to talk to oncologist before taking medications together though.
https://ascopubs.org/doi/10.1200/JCO.2018.36.15_suppl.e12527

Jump to this post

@myoga I found different article out of Sweden about loratidine or desloratidine (the prescription strength) drastically decreasing chance of reoccurrence of breast cancer. It was a cumulative article - print research which went over years of information on women who did/did not take these with treatment. Looked at women with 2+ years of loratidine. Did speak to oncologist and while he was interested, recommended waiting till more information comes out. Also found in several other articles that long term use of most of the antihistamines can have effects on the heart. I was told to use loratidine during chemo to help with the bone pain from the chemo and the Neulasta injections so it does have some effect.

REPLY
Profile picture for mistymar @mistymar

@myoga I found different article out of Sweden about loratidine or desloratidine (the prescription strength) drastically decreasing chance of reoccurrence of breast cancer. It was a cumulative article - print research which went over years of information on women who did/did not take these with treatment. Looked at women with 2+ years of loratidine. Did speak to oncologist and while he was interested, recommended waiting till more information comes out. Also found in several other articles that long term use of most of the antihistamines can have effects on the heart. I was told to use loratidine during chemo to help with the bone pain from the chemo and the Neulasta injections so it does have some effect.

Jump to this post

@mistymar
I’m not aware that long term use of antihistamines has effects on the heart. Do you remember what those effects are? Are they permanent or going away after stopping Loratadine? I’m taking Loratadine for side effects of high blood pressure medication and counting on the added bonus of decreasing chance of cancer recurrence! Talked to a doctor and he said that makes sense because antihistamines reduce inflammation which is the major cause of cancer. Then again, why only Loratadine and desloratadine have that effect?

REPLY
Please sign in or register to post a reply.