Anastrozole Carple tunnel or Trigger Thumb?

Has anyone else had issues with their thumbs on anastrozole?
I know in the side effects it states carple tunnel. If thats the same thing?

I started Anastrozole I think at the end of January 2023 but I was originally on Tamoxifen.

And probably around April time my left thumb I noticed the tendon catching and extremely painful. I contacted my GP who had our phyiso call me who suggested doing some exercises and getting a splint to support it.

However over the last month now my right (dominant hand) is doing the same.

Is this something to go back to my GP about or bring up to my oncologist? And has anyone else experienced this?
Im only 26 and I believe its because of how I sleep :roll_eyes: with my hands under my head as its when I wake up in the morning it bothersome.

Thanks in advance.

Hi Kirstie F

Somehow I doubt how you sleep has anything to do with this though it may be making it worse when you first wake up as you say.

Carpal tunnel and trigger thumb are similar conditions but in carpal tunnel nerve compression causes problems in the wrist hand and forearm whereas trigger thumb is due to damage to the tendon sheath that which stops the tendon attached to the thumb moving freely. I have a shoulder problem which was also caused by damage to the tendon - I just aggravated it by falling on it but Physio was very helpful , you didn’t say if your non- dominant hand improved after Physio ?

The person to contact about this would be whoever prescribed the Anastrozole as it could be the cause - often that’s actually the Breast Surgeon so you could reach out via your BCN . If you’re still in contact with your Oncologist then reach out to them but it might be a good idea to contact your BCN anyway and also I would let your GP know that you’re having problems as they may be able to provide practical help and advise who you need to contact.

Sorry you are dealing with this and wishing you all the best.

Joanne. X


Honestly no the exercises given didnt really help. I was just advised to squeeze a stress ball…

I kind of just pushed through the discomfort in my left as its mainly when I move my thumb/ wrist in the wrong way. But now its bothering my right hand thought maybe I should push for help/answers again.

Luckily I have an appointment soon with my oncologist for results from a bone scan and x-ray so I’ll ask then.

Thank you so much for your reply :slight_smile: x

I think it’s the pills. I’m having problems with my joints - arms, shoulders/back to a certain extent and now my hands. It’s worse when I first get up and wears off during the day. I’m going to ask my GP if I can change to Femera as when I changed before the hot flushes stopped which were bad.


I have had trigger thumb in both hands. Neither was due to Anastrozole. If it is trigger thumb, you get easily purchase thumb splints to keep the joint straight and stop that horrible click and pain. They are available online and in pharmacies. I had surgery for my right thumb, years ago, but a steroid injection into the base of the thumb (painful but only for a short time and less so than constant “triggering”) cured my left one. I don’t know why I wasn’t offered that last time - perhaps because it doesn’t always work.

Carpal tunnel, which I had surgery for 25 years ago - long before cancer dx - and I now think I’ve got in my other hand, makes your fingers stuff and sore and gripping difficult. You may also experience pain in your arm. This too can be helped by wrist splints, especially at night, to stop your wrist bending and squeezing the nerve. Cortisone injection may fix it or it’s a very common, simple surgical procedure.

It’s worth seeing a Dr or your BC team to investigate the problem and establish whether the meds are causing it. I have been referred to the neurophysiology depth to have an electric test to see if it is carpal tunnel. They might suggest something similar for you.

I hope you get it sorted.

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Yes I think you are right to push for answers and treatment other than exercises with it being in your dominant hand now . I know people who have been helped by splints and cortisone injections as well . I had joint pains and stiffness including in my fingers when I was on Anastrozole as well .

Joanne. X

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I was on anastrazole and after two months started to get carpal tunnel symptoms in my right hand. I would wake in night in so much pain and was unable to open my hand. It eased a bit in the day but didn’t stop tingling in my fingers. I came off anastrazole and symptoms stopped after a few days. I have had my meds changed but fear same is happening again,

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