Side effects from stopping letrozole?

Hi Everyone,

Hello, I'm new here - wish I'd joined before now as I've read lots of interesting and illuminating posts about letrozole.

I've been taking it for 7 years since breast cancer in 2014. Finally came off it a few weeks back, with agreement of oncologists, as wanted to get get rid of brain fog, lose weight, lower cholesterol etc. All of which may or may not have been caused by letrozole, always so hard to know for sure isn't it, especially as all of those things could just be part of ageing?

The thing is, a few weeks after stopping, I've suddenly developed acute insomnia. And I mean awake all night. Not fretting, worrying etc. - just awake. It's horrible and has me on my knees.

Like many people, I've had periods of insomnia due to stress but this is different - it reminds me of the awful insomnia I had with the menopause (I stopped sleeping then too) so it's led me to wonder if stopping letrozole can cause insomnia. The oncologists say no and I understand why (I think) - it doesn't make logical sense as stopping it would mean increased oestrogen and it's reduced oestrogen that's associated with insomnia in the menopause. But nevertheless it seems like a big coincidence and just feels so much the same.

There's lots of information out there about side effects of taking letrozole but I can't find anything about side effects of stopping. That may be because there aren't any of course!

I'd really appreciate hearing from anyone who has experienced similar - or equally do tell me if you think I've got this completely wrong.

Thank you!

All my best,

Shirley

  • Hi Shirley,

    I'm sorry to hear you're experiencing these difficulties. It's good to hear you've talked this through with the specialists, although I appreciate this still leaves you with some uncertainty.

    If you'd like to speak to someone further to chat things through, you are welcome to give our nurses a call on 0808 800 4040 (Monday-Friday, 9-5). They may also be able to offer some tips for dealing with the difficulties you mention.

    And of course if there are others here with similar experience to share, then hopefully they'll be along soon.

    Wishing you all the best,

    Ben
    Cancer Chat Moderator

  • Hi. 
     

     I've just read your post with interest.  I've read that there are no side effects coming off letrozole but like you I've been off them for 3 weeks now and have developed insomnia.    I've read that insomnia can be a side effect of taking letrozole but I didn't have a problem then!
    justwondering nearly six months on are you finally getting a good nights sleep?

  • Hello Hetty,

    Lovely to hear from you. Things got very bad for me for a while - the acute insomnia led to acute anxiety and a very difficult time. I've been part of an NHS CBTi programme for insomnia for a few months now and it's very much helping me to sleep again. 

    I still don't know what caused it to happen and am very interested to hear that you've experienced something similar after coming off letrozole. Who knows whether it's the cause or not? As I said in my original post I made the link with letrozole purely because I'd stopped it recently. 

    I hope your insomnia resolves and I suppose what I'd say based on my experience is do ask for help from your GP quicker than I did, if you need it. Good luck!

    All my best,

    Shirley

  • Hi I've been on tamoxifen for 5 years then switched to letrazole for 7 years and dr told me to stop taking letrazole x it's only been 2 weeks and i feel terrible x I've got a constant headache x feel nauseous and have trouble sleeping  x I started  vitamin B12 5 days ago hoping it would give me some energy any suggestions Jill x 

  • Hello Jill,

    Thanks for your message. I'm so sorry to hear this, it sounds like you are having a rottten time. I'm afraid I don't have any suggestions other than to ask for help from your GP or other practitioner (if you are still in the loop with oncology services for instance) and to do that sooner rather than later.

    I do still wonder whether coming off letrozole was the cause of my original acute insomnia. It was the only significant change that I'd made in the few weeks before it happened and it must surely have a big impact on the body to make such a big change. But who knows?  

    I didn't have nausea or headache, I just stopped sleeping and would lie awake all night - not worrying about anything (initially anyway) - just wide awake. Not surprisingly, it spiralled into acute anxiety and I've had quite a difficult time with both sleep and anxiety ever since. Hence why I suggest going to your GP sooner rather than later.

    Good luck! And please feel free to message me again if it would help you.

    All my best,

    Shirley x

  • Hi Shirl x thank you for replying x hopefully all of my symptoms will go away soon and I'll start feeling normal whatever that is lol funny thing is I slept really well last night that may have been the prosecco though x hope your sleeping better x Jill x