Anastrozole Allergic Reaction

I was on Letrozole for two years and started developing stiff hands. Oncologist switched me to Anastrozole, and I read all the literature on this drug.

I started having low blood pressure months after starting the drug, but discounted it, because my father had it, and I thought it was hereditary. Also, a lady and her daughter both had low blood pressure. Started having fatigue, wheezing, and shortness of breath and became concerned. I was on this drug almost a year before I found out the following.

After a really deep dive, I found this:

Rare & Serious Allergic Reaction AKA Orthostatic Hypotension (low blood pressure), Wheezing, and Shortness of Breath. Why if it is a Serious Reaction that the drug companies do not list this, is beyond my comprehension.

Talked with my Oncologist, and we discontinued the Anastrozole. 3 to 4 weeks later, my blood pressure has returned to normal, wheezing and shortness of breath has almost disappeared. Ladies, monitor your blood pressure when on this drug. Report to Oncologist if you are having these problems.


Go to Https://

Put In Search Bar Possible Side Effects of Anastrozole
Under: Tables of Possible Side Effects for Commonly-Used Oncology Drugs
Click on Anastrozole

Pass this information on to your Oncologist, awareness is key!


Thanks for sharing the info .

Thanks, suesandy, for taking the trouble to report this.

I found it horrifying when I realised that oncologists only give the headline benefits and dismiss the common side effects as manageable for most. Is it deliberate that they don’t give the patient full information on the ‘cons’ so as not to scare them out of taking their wonder drugs? How cavalier and patronising. Or is it simply that they don’t keep up to speed with the latest on the hazards of each drug as we trust them to? How remiss.

Either way, seriously ill, confused and frightened patients deserve so much better.

Dear Misty K
Absolutely bang on.
Agree that speaking to Oncologist is essential but doing so was like getting a tea invite with King Charles.
I am now on an ok brand of Anastrozole despite it being often unobtainable.
Agree that crippling pain that seriously affects QOL is often dismissed by professionals as what we should put up with to have the benefit of taking HT drugs.

Can anyone explain to me why there is a one size fits all dosage: s.o. with a Stage 1 grade 1 HR+ gets to take the same dose of these drugs as s.o. with grade 4 with mets?

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Hi wbm1711

It’s only an educated guess (so hopefully if I’m wrong, a nurse will correct me), but aromatase inhibitors, of which Anastrozole is one, suppress oestrogen production in the body because this hormone feeds breast cancers, some types more so than others. I imagine that at whatever stage the cancer is, this is just one tool in the box that might help prevent/slow cancer growth. The dosage is the same because it is always aiming to erradicate as much oestrogen as possible. A more advanced cancer will obviously be having a lot more thrown at it besides. (Hope I’ve got this right!)
I was scared off AIs in general, by the possible serious consequences, and by the all-too-obvious debilitating side effects (after 10 months of persevering). I’m not a lightweight but they were changing the person I was too much.

Thank you for thinking it through - I expect you’re absolutely right!
I so hate the side effects and daily reminder as well as lack of transparency surrounding AIs - if they’re all I’m taking I guess I’m lucky