Letrozole: When will I start feeling/seeing side effects?

Posted by francine6829 @francine6829, Mar 8, 2019

I started taking Letrozole (Femura) about a month ago. When will I start feeling/seeing side effects? what are the main side effects you have? Does anyone not have any side effects?

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

I have been on this med a couple months. My oncologist said worst side effects his patients reported were hot flashes and joint pain. I have experienced some joint pain on occasion but Aleve did the trick. I didn’t experience the side effects until about 2 months on the drug.

REPLY

I'm taking alpha lipoic acid (ALA), a non-prescription drug in the US but a prescription drug in Europe. I doubled the dosage after the side effects from Letrozole, some of which were to make my peripheral neuropathy in my feet and legs much worse. My neurologist reviewed it.

REPLY
@deluga

How Fast Can Letrozole Side effects appear?
On the third day of taking letrozole, I felt as if an ice-pick had pierced my ear. The pain was excruciating and I stopped. Many painful side effects are still there - pain in ears, jaws, neck, mouth. My oncologist says this can't be caused by letrozole because it takes more than 3 days and the side effects would disappear when I stopped taking it. I've gotten some relief from increasing the meds I take for peripheral neuropathy. Does anyone have any information on how long it takes for letrozole side effects to appear? Any scientific studies too?
Thanks for any information.

Jump to this post

@deluga, I moved your message to this existing discussion:
- Letrozole: When will I start feeling/seeing side effects? https://connect.mayoclinic.org/discussion/letrozole/

I did this so you can read the experience of others and connect with members taking Letrozole.

Like all medicines, letrozole can cause side effects, although not everyone gets them. And how long it takes for side effects to appear is different for every person.

Common side effects of Letrozole mimic menopause symptoms and include hot flushes, difficulty sleeping, tiredness and low mood. Side effects usually improve after a few months as your body gets used to the medicine.

The side effects that you're experiencing sound rare and potentially not related to Letrozole or something that is very unique to you. Perhaps a drug interaction with another drug you're taking. There is also something called ototoxicity - hearing or balance problems due to a medicine. This can happen when someone is on a high dose of a drug that treats cancer, infections, or other illnesses. Might be worth talking to your pharmacist.

What medication are you taking for peripheral neuropathy? Did you increase the dosage under the guidance of your doctor or pharmacist?

REPLY

How Fast Can Letrozole Side effects appear?
On the third day of taking letrozole, I felt as if an ice-pick had pierced my ear. The pain was excruciating and I stopped. Many painful side effects are still there - pain in ears, jaws, neck, mouth. My oncologist says this can't be caused by letrozole because it takes more than 3 days and the side effects would disappear when I stopped taking it. I've gotten some relief from increasing the meds I take for peripheral neuropathy. Does anyone have any information on how long it takes for letrozole side effects to appear? Any scientific studies too?
Thanks for any information.

REPLY
@francine6829

My oncologist put me on Femura rather than the one you are taking as studies show it has fewer side effects.

Jump to this post

My onc never mentioned it!! Only 3 other als which I could not tolerate... Now bc is back!! New oncologist only mentioned Letrazole!! After I have suspicious lymph nodes removed. Can't wait to start it!! Anyone have small dissection?? How bad is tube??!!

REPLY

@francine6829 : Not sure this will ever reach you, since your original post was years ago. I tune in from time to time on discussions regarding AI meds, and yes, there are people like me who have no issues with taking them (Letrozole). But then, I tend to not really react to medicines, generally speaking. Any pain reliever other than Aleve is pretty much useless, any OTC anti-histamine does not do much…………… so, in this instance, I DO hope that the Letrozole does work - since I can’t tell by just taking it.

REPLY
@deluga

Update: Soy and Letrozole
Although the pain from taking only 3 doses of Letrozole was getting better after 3 weeks, all at once I had horrible stabbing pains on my arms, neck, more neuropathy, and numbness. It was so bad it kept me up all night. I recently became a vegan and had just switched to soy milk and for the first time, had tofu for 2 nights in a row. (Studies have show that women who eat soy have lower rates of cancer and it's about the only food that helps with triple negative breast cancer which I hav3). Since that was the only significant change I had made in the last 2 days, I googled soy and letrozole and a study was done on taking them together. Bottom line was DON"T TAKE THEM TOGETHER!!

Jump to this post

I wonder of the reason for avoiding soy is because it purportedly (I keep finding conflicting medical opinions) is estrogenic. Since letrozole is taken to block estrogen production, taking the two together could be counter-productive.

REPLY

Update: Soy and Letrozole
Although the pain from taking only 3 doses of Letrozole was getting better after 3 weeks, all at once I had horrible stabbing pains on my arms, neck, more neuropathy, and numbness. It was so bad it kept me up all night. I recently became a vegan and had just switched to soy milk and for the first time, had tofu for 2 nights in a row. (Studies have show that women who eat soy have lower rates of cancer and it's about the only food that helps with triple negative breast cancer which I hav3). Since that was the only significant change I had made in the last 2 days, I googled soy and letrozole and a study was done on taking them together. Bottom line was DON"T TAKE THEM TOGETHER!!

REPLY
@francine6829

Cindy, I love your post and AGREE about the levels. How do the docs know if we are taking too much or too little. This is ridiculous. Interesting fact, my oncologist says for prostrate cancer, they do take and monitor progesterone levels. Cindy, where do you live and was it your oncologist who took the estrogen levels or a different doctor?

Jump to this post

francine6829 This may be a bit ridiculous but I am replying to you THREE years later. I'm sure you've moved on and figured this out by now!! Ha ha. I was distracted by my husband's serious medical issues and cancer diagnosis and am just now getting back to Mayo Connect. Sorry for not replying sooner to you and I hope you are well and coping. Hugs.

REPLY

I got off it after 3 days. I cheated and only took 3/4 of a pill. Made my neuropathy much worse and numbness on neck and face. It's been almost 3 weeks and the pain has not gone away. Glad though that you're able to take it.

REPLY
Please sign in or register to post a reply.