Osteoporosis meds and mast cell activation syndrome

Evenity contains polysorbate 20 as an inactive ingrediant. The polysorbates have the potential to excite mast cell activation. I haven't any suspicions about Tymlos, though some people cannot tolerate the medication. Some are allergic to the preservative. Forteo avoids the preservative. I don't know enough to actually answer the question.

Hello. I also have MCAS and have struggled immensely with all drugs since my diagnosis in 2023. My endocrinologist at HSS in NYC is Jessica Starr. She was actually the doctor who suspected that I might have MCAS and sent me to my current immunologist Jennifer Toh in NYC to have me tested for it.

Dr. Starr at HSS is suggesting that I take Reclast infusions, but I am terrified of them because the drug stays in you for a long time. I have had anaphylaxis twice on other medications and don't want to get a medication that might cause me serious problems. I would rather try Forteo or Tymlos since they leave the body more quickly.

Please keep in touch and let me know what you decide to do and how the medications affect you. With MCAS medications are such a challenge. Good luck to you!

Any updates? I have MCAS and am about to start Forteo.

@jklotzkin I just tried 3 days of Tymlos injections and had increasingly severe mast cell reactions so my hematologist said to stop it. I'm not sure if Forteo will be different enough for me to tolerate it. Have you done well with it so far? Thank you.

@nytl I really appreciate you sharing. I have not started on the Forteo yet due to my doctor wanting my MCAS more stabilized before trying. The only reason I am even considering it is that it supposedly leaves your body within 24 hours. But I’m also concerned that following the Forteo I would have to be on medication. Anyway I’m sorry to hear that it didn’t work for you. I wish you well!

I saw Jessica Starr at HSS, and she claimed Reclast would leave my body within two weeks. She offered no alternative medication. From reading a Mayo Clinic book and other sources, I knew that her statement was incorrect. I saw another doctor about osteoporosis drugs. He is completely opposed to any infusions for patients with MCAS. In his words: "You would suffer so much." According to this NYU doctor, Reclast binds to the bones and can stay in your body for up to a year. If you have a bad MCAS reaction to this drug, it would be terrible. I heard the same from an orthopedist I visited in Germany. The NYU doctor recommended Tymlos since it can be stopped right away and leaves the body within 24 hours.

I was also told that it is a good idea to do a "challenge" in an immunologist office. Take just a small amount of a drug to see if you will have an allergic reaction. Premedicate with prednisone if you can handle it and antihistamines.