What are the side effects of Kisqali and Aromatase Inhibitors?

I have been taking anastrozole for 8 mos. Have had a variety of side effects, nausea-taking at night eliminated this, hot flashes- not as bad as menopausal, fatigue and joint pain. I find that non weight bearing exercise helps with the joint pain, bike and swimming esp. I am 68

Hello Loretta. I’m taking KISQALI and probably the symptom I have had is upset stomach. Hope this helps.

Hi Loretta.I've been taking Letrozole and Kisqali. So far the only side effect from Kisqali is fatigue. I've been taking it for 2 months now. My oncologist checks my white blood cells regularly and they were low several weeks ago,hence the fatigue. So she took me off of it for 2 weeks. I was still able to work my job as a nurse . The fatigue was not severe but I just had to manage it. Also the only side effect I've had with Letrozole was mild nausea the first day and then it went away. I take that at night and that helps a lot. Also I try to eat prior to taking Kisqali to prevent an upset stomach which is another side effect of that. So far that's been working. It's hard to make a decision about these meds because of the side effects as they can be very concerning. But i think you will be fine ,given the fact that you are so active. That is an advantage for you. God Bless you.

Hi Loretta! I know just reading the side effects of the AI’s is enough to scare anybody off. My advice is to try them as about 50% of people tolerate them pretty well. I started on a Anastrozole and then moved to exemestane.  Unfortunately I developed every side effect in the book and was pretty miserable after roughly 4 months on each of those two drugs. My oncologist then switched me to tamoxifen, which is slightly less effective, but I seem to be able to tolerate so much better. The biggest issue I had was the extreme joint pain and muscle ache, in addition to the sweats and insomnia. I went back to my oncologist and said that these drugs were no longer an option for me. They don’t like to move you to tamoxifen ahead of two years, but it was either that or nothing for me as I had made the decision that I couldn’t manage it on the new AI’s. My best advice is that we’re all different so try the drugs and be a big advocate for yourself of what you’re willing and not willing to do.

Also, when you try any of the hormone drugs, my advice would be to taper them up a bit more slowly as it gives your body more time to adjust. My oncologist was willing to take that approach and I think that’s relatively common.

I am about to start my second cycle of Kisqali. I have been on Letrozole since a few weeks before my lumpectomy with no side effects. I had a number of unpleasant side effects with 600mg of Kisqali, including lower than acceptable white blood cell and pllatelet counts, diarrhea, loss of energy and insomnia. I was early stage, but had LVI which is why I plan to stick with it, although I am moving to a lower dose of 400mg. According to Novartis and the FDA, this will be just as effective for non-metastatic breast cancer. Other than the blood changes, the other side effects are manageable. I found Imodium stopped the diarhhea, magnesium glyconate helped with the insomnia. Plan on getting your high-energy projects done during your one-week hiatus because there was, at least for me, an immediate difference in stamina. I'm told that my body will adjust to most of the side effects other than the low blood counts, so we'll see.

Many people in this community have shared experiences with both medications, and side effects can vary greatly from person to person. While some do experience joint pain, fatigue, or other challenges with aromatase inhibitors and Kisqali, others find the side effects manageable or have minimal issues, especially with proper support and monitoring from their care team. The decision about treatment is deeply personal and should involve thorough discussions with your oncologist about your specific situation, lifestyle priorities, and the potential benefits versus risks. Consider asking about strategies to manage any side effects that might arise and whether there are different medication options that could work better for your active lifestyle.