Has anyone taking Tamoxifen experienced heartburn with abdominal pain?

I haven’t had any heartburn with tamoxifen. I’m 69 have been taking tam for 15 months total. 20 mg for 6 months, 5 mg up until 2 weeks ago. I’ve cut the pill down a little more so I’m getting 2.5-3.5 mg. I had headaches 24/7, tinnitus, and brain fog that came on strong after the first 3 months. Headaches stopped when at 5 mg. Tinnitus is less. I thought brain fog had pretty much disappeared but was gobsmacked during an event that showed how poorly my brain was working!! So I’ve lowered it again.
But never any heartburn. Hope you find a solution to it!

Thank you , good tonknow we have to do things that decrease some of the side effects for us
Sally

You always want to look at your risk level before lowering the dose. Some times the risk is high enough that you have to just weigh benefits and “losses”. When I share my lowered dose I worry that someone else will think it is safe, and it may not be.

I understand But I feel one size doesn’t fit all If I hadn’t researched the possibility of try the drug by another manufacturer I don’t think I would have been staying on the prescribed dose 10 mg didn’t reduce some of the s/e’s for me but what a difference in trying another manufacturer I do have osteopenia which Oncologist felt would help with more bone loss. Hope it continues to reduce the s/e’s But I appreciate you clarifying response
Sally from CA

I am sorry you've experienced these side effects. I had IDC and surgery in 2022. With 10 mg of tamoxifen I experienced extreme exhaustion and digestive issues which included abdominal cramps, nausea, loose stools. I also had intense brain fog and could not function. These symptoms lasted all day. My oncologist would not consider prescribing 5 mg. I cannot take AI's due to severe osteoporosis. I stopped tamoxifen after a few weeks and am not taking any anti-hormone medication.
I do take omeprazole and Pepcid for major reflux/gastritis caused by Herceptin. My GI says it is fine to take antacids while on the other meds I take. Omeprazole is the only med which controls my acid reflux/Gerd.
I hope this might be somewhat helpful for you and I really hope your symptoms lessen. All the best.

Guidelines changed at MD Anderson in 2022 and they came out with an update on care, including tamoxifen, later that year. When I saw the survivorship provider at MDA in April 2022 the guidelines were still for 20 mg, later in the year they added 5 mg as an option for those who could not tolerate 20 mg. MD Anderson has nomograms they have developed that guide practice. They are available to view on the web, you can search for them. I found a nomogram that matched my issue (DCIS recurrence risk), and brought up the new guideline with them in October 2022 and they agreed to the 5 mg. Mayo Clinic probably has something similar. I found guides by Memorial Sloan Kettering on the web, as well.

You might ask your oncologist to re-look at your case. In 2022 they may have been following current guidelines.
The National Comprehensive Cancer Networks 2023 guidelines on breast cancer risk also should show that 5 mg is an option, but with lower efficacy.

Thank you I appreciate the information
After much discussion with my oncologist telling him I had changed manufacture and started Tamoxifen 5 mg daily he ordered it The heartburn and acid reflux just starting at night with some abdominal pain I usually take Tamoxifen around 10 -11 AM Wondering if might be better to take at night
I did buy over the counter Pepcid to see if that might help Going to try today I go next month for my mammogram That will be my second 6 month check which will be 1 year since my surgery for Invasive ductal carcinoma
Thank you for the information
Much appreciated I will look up the guidelines and risk factor
Wishing you the best
Sally in CA

Thank you for your information We try to comply with treatment
But often feel the need to critique prescribed treatment
So comforting to learn not alone and sharing information that others have found out and what worked for them
Sally in Ca🙏

I am a 74 yr old healthy before breast cancer (Stage 1B Invasive Lobular) 3 years ago. On AIs I had severe GI problems- abdominal pain, reflux, intractable diarrhea, nausea. I did 4 trials with 2 different AIs and I was so miserable and incapacitated with no quality of life. Given my age I decided to take my chances with the cancer recurring. After stopping the AIs it took several weeks before it cleared out of my system and the symptoms abated. I returned to good health and active life for a year, then my oncologist convinced me to try baby Tam-- 5 mg. I lasted a month and then got all the same reactions, even worse. It has been over 3 months since I went off the Tamoxifen and am still dealing with severe GI issues. I just consulted gastroenterologist who did a lot of testing that all came out negative, then did a colonoscopy even though I had one 3 years ago that showed no problems except mild asymptomatic diverticulosis (common at my age). Now he found my diverticulosis was much worse, and that I have what he called tortuous colon. This can be congenital but I never had it before and it can also be caused by prolonged constipation. I am sure that the AIs and the Tamoxifen are the cause. I am waiting to find out what recovery from this will entail and am very worried. At no point did my oncologist offer me any support for managing my GI side effect, just kept telling me that this was not a side effect that she had seen and was not usual. It may not be the most common side effect, but everyone is different and it was definitely a side effect for me. I started looking it up online and found that many women do have serious GI issues on these drugs., especially post-menopausal women. But estrogen blockers are all doctors have to reduce the chances of recurrence and they just look at the statistics. I do now live with the reality that my cancer may metastasize or recur in my remaining breast, but I feel that on the drugs life was not worth living. A younger woman might make a different calculus. I am doing all the alternative/ healthy active lifestyle and diet that I can and hope I can have a few more good years with my husband and to see my granddaughters grow up and finish my creative projects.

Consider investigating motility issues, SIBO, and sensitivities to gluten, histamines, and salicylates. And if you consume any alcohol, any at all, STOP. Gut bacteria is serious business and you need to get that right for nutrition, meds, and your immune system to work. GI testing yields useless data if not properly timed and sequenced. For example, two weeks after seeing me, a GI scheduled me for an upper colonoscopy to test for celiacs, plus a SIBO breath test, and two other tests. I researched them then cancelled all of it: the data would have been meaningless and my $ wasted because the procedures were not sequenced or timed at all. For example: you must ingest gluten for at least six weeks prior to the upper colonoscopy to stimulate a reaction that would surface the celiac’s. That GI was all about the coding + insurance $, not the outcomes: he would get his reimbursements while useless, inaccurate data would have left my issues unsolved. I changed GIs. Using the paid versions of ChatGPT and Gemini, I do my own research. It does not replace doctors, it makes me an informed, shrewd consumer of medical services, a consumer who asks better questions and better understands and manages my own health. I urge you to research anything in this post or your experience that is new to you. YOU are your best advocate, and the ONLY one totally vested in your best health outcomes.