Severe side effects - advice please

Hi, I hope someone may be able to offer some advice on this.

I’ve been on letrozole for one year and the side effects - the worst of which is joint pain - have got so severe that I can’t take it. I had joint pain in knees, hips, neck but the worst in my hands and wrists. I was crying with pain in the mornings and had to wait an hour for my wrists to loosen up so I could shower and dress after taking ibuprofen. For the last few days on this I couldn’t pull on my compression sleeve for lymphoedema or even sign my name.

I did try a switch to aromasin but was very sick on this so that wasn’t an option.

Is it worth trying arimidex or should I switch back to tamoxifen? I’ve been offered the choice. Has anyone else been through anything like this?

Elinda x

Bumping into latest posts for Elinda

Hi Elinda,
Yes, I had serious hand problems with Arimidex and went back to Tamoxifen. My onc and gyn prefer Tamoxifen anyway (I’m 66 now) because it’s long tested and all the side effects are well researched. The onc said that at San Antonio they say AIs give a slightly better prognosis for non-recurrence, but people don’t live any longer - he thinks it’s because they get less exercise and more heart disease as a result, on average - that’s just guesswork of course. I find Tamoxifen much better to tolerate. I must admit, though, that I would rather die without a recurrence! but I can’t remember if you have secondary cancer or not - I haven’t.

After a couple of years I was getting too much build-up of whatever it is in the womb, so went to Exemestane, in which I have fewer side-effects than on Arimidex, although a year on my joints are increasingly stiff when I get up.

Anyway, that’s my personal experience. As i’ve been treated in Germany, AIs have been on the market for a shorter time there and hence probably the willingness to give Tamoxifen after menopause.

Hi Zeppa

Thanks for your reply and that is reassuring. I don’t have secondaries so my Onc and my surgeon have said that I may have to switch back to tamoxifen because of the joint problem. I had a hysterectomy a few years back so I wouldn’t have to worry about the uterus problems.

I do worry about the recurrance issues (I’m 49 now) but at the same time, I am becoming less and less mobile on AIs and the issue with the wrists is so severe that I was nearly to the point of not being able to dress myself in the mornings!
I’ve been off all tablets for 4 days and with each day I’ve got less pain and more joint mobility - it’s incredible. I had a week’s break back in June and found the same thing. I’m not taking anything at the moment because I’m waiting for my arimidex prescription (long story, lots of secretarial mess ups) but should start them hopefully early next week.

I think I’ll give arimidex a try because that way I will have tried them all and then if I can’t tolerate it I’ll go to tamoxifen knowing that I’ve given AIs my very best shot.

Elinda x

Hi Elinda,

I’ve been on Letrozole for about 14 months. I have had terrible joint pain from about 48 hours after starting it, so I switched to Arimidex which really wasn’t much better. I am 54 and post menopause which is why I started on AI’s after treatment. So I have now switched to Tamoxifen and have now been on that for about a month and I still have the joint pain and now I have headaches, more flushing than on the AI’s and in the last week I have noticed a heaviness in my uterus/abdomen area and am worried that something is going on there!!!
I am coming to the conclusion nearly 2 years post starting my hormone therapy that they all have something detrimental to them. Am going to talk to my GP and breast doc and see what is the way forward, cos I don’t like this new heavy (like I’m about to start a period) feeling…Want to get something sorted as I’m young (ish!) and do not want to go on like this!!
Hey ho…breast cancer the gift that keeps on giving!!
I think the point is you’re not alone!


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Hi elinda and others. I reached the 5 yr. mark last December, and looking forward to no more pills (previously Tamoxifen and two months Letrozole) I was dismayed to hear my onc. recommend Letrozole as a adjuvant therapy for at least a further 2.5 years.(Latest research with this drug is that recurrences are much fewer. I might add that my prognosis was / is ‘good’). Of course I thought I could do it…we all want to extend whatever life we might have for as long as possible…Tamoxifen for the most part had been fine, but I developed really serious cramps in both legs towards the end of the 5-years, so changed to Letrozole, which gave me cramp- free legs. However, now almost a year on Letrozole and I feel about 96! I ache all over…wrists and fingers of late, neck and arms. I can no longer squat easily, especially in the mornings. Since I am a musician and play the piano, these latest symptoms are becoming more than worrying.Fingers are stiff and slow and hurt. I am constantly exhausted because of the pain and standing up for long periods of doing anything physical, like gardening, are becoming almost impossible. I don’t know how long I can tolerate this drug. I also wonder whether the aching will stop once I come off it. My parents were badly arthritic and I know I have some. Am I making my arthritis worse? I was anorexic as a teenager. Am I aching more than usual because of this? I honestly feel that |I will break in half at times. I have noticed that when I am feeling a lot of pain like this my heart starts beating quickly too…so I am doing a lot of lying down. Is anyone else experiencing such severe symtoms? I really wonder if my body is saying that I really don’t need to take this drug any longer. Incidentally, I opted to take it for the extra time, my onc. just presented the facts and gave me the option to take or leave it.Advice would be really welcome and thank you. PS I am now 57yrs.

Hi everybody,

I’ve been taking Anastrazole since 4th July and as yet, I don’t think I’m getting any side effects. I don’t really know if it is relevant to any of you, but most of us on these AIs are post menopausal, and of an age where arthritis might kick in. As a rheumatoid arthiritis sufferer of nearly 30 years, a lot of the symptoms are very similar. Maybe before making any major decisions about whatever AI you are on, perhaps you could ask your GP to rule out arthritis first. I know there is a lot of pain involved but keeping still will only make matters worse (voice of experience) gentle exercise or if possible swimming, might help.
By the way, I’m 62 and when I was 36, the only way I could get upstairs was by dragging myself up with my elbows!! I can now walk, but only one foot followed by the other foot onto the same step, before moving on to the next one.
Best Wishes
Poemsgalore xx

Hi Wandy, Allegra and Poemsgalore

Poemsgalore - pretty sure it’s not arthritis as the pain diminishes within days of stopping the AIs. It it carries on that is one avenue I would look into.

I’ve made the decision to stop AIs and start tamoxifen - this was what my consultant thought was best too. I was on tamoxifen for 2.5 years before I became menopausal. That wasn’t great for me either at all. I remember getting a lot of cramps on tamoxifen but not severe ones. I did though have a very ‘fuzzy’ brain and some joint pain. I’m lucky that I’ve had a hysterectomy.
Letrozole I’ve been on for 14 months. The pain has been disabling the past two weeks so I’ll have to see what happens now I’m on tamoxifen. I’m taking ibuprofen but I have stomach problems so that’s really a no-no but paracetamol doesn’t touch it. Because it’s affecting my neck I’m also getting terrible headaches which make it hard to function.
I think for me it’s weighing up a number of things but becoming virtually immobile, in terrible pain and housebound can’t be good in the long term. I think if tamoxifen means that I can do regular exercise and limit the painkillers then that must help too. Also have put on a lot of weight with the AIs even though I was at Slimming World and sticking to the diet! I do though worry though as my risk is high given the size of the tumour and lymph node involvement.

I have read that have found that people who have severe side effects on AIs (which is only a tiny percentage) have a certain gene. So there you are - those wonderful genes again!

I’m so disappointed because the first 6 months on letrozole I felt great and I thought that at last one part of my treatment was going to be easier. No such luck!
take care all
Elinda xx

Hi I have been on letrozole for over a year and I found that the pains were worse with certain brands I am using the Teve brand at the moment and have no pains last month my chemist supplied me with another brand and my knees and feet acged all day it was so bad that I could not slepp on a night time.
My doctor presciped the teva brand when I explained about the side effects but I am having a problem getting them from the chemist as they say that they are dearer than the others but I am going to persist

What would other brands contain that Teve brand doesn’t. that would cause the SEs to be worse? When you buy paracetamol, it doesn’t matter what brand you buy surely, they all do the same thing.

Hello Barbara
I looked into the various ingredients in Letrozole as I was having problems and I found Teva was the best as I wasn’t allowed to have Femara as it was too expensive. Teva and Femara does not contain hypromellose, I think that it is in the coating. I don’t know why you can’t have Teva, it might be more expensive that some brands but is certainly not as dear as Femara. My Onc insists that if the SEs are bad on the generic versions then Femara should be prescribed so these generic versions can be a problem for some people.

I use hypromellose as eye drops! They are used as an artificial tears replacement. I didn’t know it was used in tablets Until I found this:
"Hypromellose (INN), short for hydroxypropyl methylcellulose ( HPMC ), is asemisynthetic, inert, viscoelastic polymer used as an ophthalmic lubricant, as well as anexcipient and controlled-delivery component in oral medicaments, found in a variety of commercial products.<sup id=“cite_ref-1” class=“reference”>[1]</sup><sup id=“cite_ref-2” class=“reference”>[2]</sup>
As a food additive, hypromellose is an emulsifier, thickening and suspending agent, and an alternative to animal gelatin.<sup id=“cite_ref-3” class=“reference”>[3]</sup> Its Codex Alimentarius code (E number) is E464."


I have been on Letrozole since March and have been suffering with joint pain so onc said I could stop taking them for a few weeks to see if it was the drug causing the pain. After only 4 days without the drug my pain doesnt seem as bad so will see what develops in the next few weeks as I am not due to see ONC till september I dont know what he will prescribe as an alternative

I was prescribed Letrozole in April last year after a second mastectomy and reconstruction on both sides. I had DCI with no gland involvement. After 4 months I was in so much pain in my hips and buttocks and also in my thumb when driving that I came off it. I saw the Consultant and said in view of my diagnosis whas it really essential that I took anything. After a multi-disciplinary meeting it was decided that I really wouldnt get benefit from taking anything. While I am grateful for this I do think, in view of the known side effects of Letrozole, that they should think very carefully before prescribing it. I have had lots of physiotherapy and various massage etc. but I have had to give up my exercise classes and swimming because I couldnt climb down the ladder into the pool. Some days I am nearly crying when walking the dogs, with pain mostly in the Piriformis muscles in the buttocks. Nobody seems to be able to give me any answers as to why this is still happening but I was a very active 73 year old when it started and I feel that I have aged 20 years since the oestrogen was taken away. I wonder if it replenishes itself, I do hope so. I don`t like to moan as there are ladies much worse off than me but Letrozole definitely changed my life for the worse.

I had 5 years of Tamoxifen and now on Letrozole until next April which will be 5 years. Can’t wait but have had so much discomfort with Burning Mouth Syndrome which started about 6 months into starting Letrozole. Apparently 1 out of 3 postmenopausal women get it and is due to lack of Oestrogen so I guess Letrozole is working.
Decided to take a break from it at Christmas, didn’t say anything to my Onc or GP but started getting so much aches and pains my Onc arranged for me to have a full body MRI scan(at this point he knew about me taking a break and not too pleased about it) it came back clear and I decided to start taking Letrozole again and to continue till the 5 years are up. It was only at this time after 4 years that he said that aches and pains are due to Letrozole, can’t get him to agree about BMS even though it is well known that it is caused by lack of Oestrogen.
Last few days my mouth as been so sore and burning and I usually have a hot flush at the same time and I am thinking of stopping until after my holiday in 2 weeks just so I feel a little bit better while I am away.
It is excellent that there are the drugs available to keep this horrible disease at bay but it would be helpful if the experts recognised that there are SEs and be honest about them.

Seems like I’m definitely not the only then!

I’m lucky insofar as my Onc and surgeon take me seriously re the joint pain. I think I’ve got to know my surgeon so well that he knows straight away when I say something is bad that it is.

I do also suffer from terrible acid reflux which started 5 days after last chemo. I’ve repeatedly been told that if it was the chemo that would only be temporary. I’m now 4 years on and its still bad. Have had endoscopy and nothing showing. Interestingly, it seems that gastrointenstinal problems are another side effect of both tamoxifen and AIs so I’m left wondering how much of an effect these are having on my stomach.

I’m now off the AIs for 11 days and 3 days into tamoxifen. Today is the first day that I’ve had a bit more movement in the joints and have even been able to vacuum the house (and yes, the house was filthy). I’m still on painkillers but it’s good to feel it easing slightly. My wrists are definitely feeling better today.

Mmosen3 - you have oestrogen in your body fat which is why AIs are prescribed even after menopause once the ovaries stop producing it.

Annw - Please let us know what your Onc says.

As to side effects from different brands - I have heard this before. I think the different brands may have some impact on some people if they can’t tolerate different added ingredients but I don’t think very severe joint pain would be because of this. All brands must have the same amount of active ingredient or their efficacy would differ. I’m sure I’ve had various brands of letrozole. My pharmacy seems to change the brand of drugs I’m on on a regular basis - must be shopping around!

Elinda x

ive heard this about the different brands too. i’m about to start tamoxifen after rads in a few weeks but last year i had zolodex for endymetriosis which has similar s/e’s to tamoxifen so i’m hoping i will be able to cope. i’m struggling at the moment with the joint pain from the last docetaxol so i dont fancy any more starting.
angie xx

I have acid reflux as well and take Omeprazole in the morning, which also helps with my stomach when I take Ibroprofen.

i recently came off letrazole because of the severe joint/bone pains, was put on tamoxifen, which i find a bit of improvement, i`ve only been taking it for a month, still have all the other side affects, but joint pain not so bed now! copable xx

I’ve been on Letrozole for 6 months and initially had quite severe pain in my bones particularly in my legs. That gradually disappeared but I still have pain in my hands, elbows , shoulder and neck. I already had sero-negative arthritis and osteo-arthritis so my Oncologist suggested a re-referral to rheumatology. I saw them last week, have now been given tramadol for the pain and a tablet to help me sleep so I can cope better with pain during the day. After less than a week on this new regime I’m already feeling more in control and able to cope. It will be interesting to see what the rheumatologist says when I see him again in 4 weeks time as he’s done loads of blood tests and x-rays of my hands  to check if it is Letrozole related pain or a deterioration of my arthritis.