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🙏