diazepam/citalopam does it interfere with tamoxifen

Hi all, I have been taking tamoxifen for over a year and my periods stopped after fourth chemo.A few months ago my GP put me on diazepam and citalopam after a family bereavement,as soon as I started taken them all tamoxifen side affects vanished and on friday I started a period very heavy, and I had been getting period pains a few days before.Has anyone else experienced anything like this,and do you think the tablets stopped the tamoxifen working.

best wishes mell xxx

I don’t think diazepam affects the metabolism of Tamoxifen but some of the SSRI drugs (particularly paroxetine and fluoxetine) could reduce the effects. I would ask your GP regarding citalopram, and also Google it - the action of the SRRIs in conjunction with Tamoxifen has only recently been realised.

I am on Venlafaxine (Effexor) which is only a very weak enzyme inhibitor and I have been assured it is safe to take with Tamoxifen - I was on Citalopram before and as far as I can tell thay have exactlt the same effects on anxiety/depression.

Hi Mel

If you would like to talk this through with one of our trained members of staff on the helpline please do give them a ring, they will be able to offer you support and information. The number to call is 0808 800 6000 and the lines are open 9am to 5pm Monday to Friday and 9am to 2pm Saturday.

I hope this helps

Kind regards
Sam (BCC Facilitator)

Thanks for your reply starflower and Sam,I am going to see oncologist tomorrow so will ask him,my GP isn’t really that good.I think I need councling,not only for the cancer but for the bereavement aswell my head is all over the place.

thanks again best wishes mell x

Hi Mell

I have been taking citalopram for 2 years…started my tamoxifen in September. I dont have too many side effects but it had never crossed my mind that the citalopram could be affecting it.

I will ask my consultant too when I next go to see him.

Judy x

It may all just be coincidence.but everything did change as soon as I started taking both diazepam and cetalopram together.Hot flushes stopped and I was getting terrible night sweats these stopped too.About aweek before the period I was getting really agitated(spelling)like PMT,along with period pains,so I am hoping it was a period and nothing dodgy going on.hopefully will find out tomorrow.

best wishes mell x

hi melly
hopefully your doc would look at your medication you are already taking and check that it wouldnt be effected by new medication. i too am on citalapram, and my docs havnt said anything, i have some side effects from tamoxifen, but i dont believe its cos of other meds.

i hope your mood levels lift soon, it is really horrid being deppressed, i have felt bit low lately, but not as bad as when i started antideppressants some years back, but i dont intend to come off them until my moods are level.
i hope you dont expect too much from yourself, while your feeling like that, i find company helps me, even though i normally dont feel like bothering and chatting is difficult when you feel that way.
but it does lift, and you do learn how to handle it in a different way, the counsellor is a good idea, i hope the docs sort it.
take care x

Thankyou Everydaymatters,my oncologist said that dizipam along with citalopram may have affected the tamoxifen and said that he doesn’t like giving antidepresants to women for hot flushes as he is not sure if they interfere with tamoxifen,but he did say that for depression the most safe one was the one that starflower mentioned.My GP was 100% sure that they would not affect the tamoxifen.I wish they would all get together and come up with the same answers.I am seeing a counselor on 26th may and am really hoping this helps me.I am so,so down you see we lost our 18 year old daughter to meningitis in December.The cancer doesn’t seem that important to me anymore,I just worry about the affect it would have on my other two children and my husband if it was to come back,they have been through soo much already.I am just soo mixed up and can’t make sense of anything anymore.

love and best wishes mell xx

Dear Mell

You have had a very difficult time over the last year. I very much hope the medication helps you to feel better.

I moved home recently purely because of the inadequate medical care I got at my previous home - 4 years misdiagnosed with breast cancer despite three visits with concerns and requests for a mammogram. It was in a very rural area and I could not find another Practice to take me on hence I moved home. At that time I was in a very dark place and was put on Efexor Venlafaxine as my oncologist said this was the best one as it also helps with hot flushes. I have recently joined a new GP Practice and the GP there did not want to give me venlafaxine. She said she did not want to give me it because it gives you hot flushes?? Quite the opposite of what my oncologist had said. She has given me citalopram saying it’s a very good drug. I didn’t question it as I’m trying to build a new relationship with another GP and in light of what has happened in the past, I may not find this very easy. I have not been taking the citalopram for very long but am wondering who would be best placed to confirm that it’s perfectly safe to take with tamoxifen. I don’t feel inclined to ask my new GP and am not seeing my oncologist for another 6 months.

Wishing you all well.


Hi Jeannie,4 years misdiagnosed that is terrible.We put our live’s in our GP’s hand’s and so often they get it very wrong.When I first went to my GP about my breast she said it didn’t present as breast cancer and said she would refer me to breast clinic but as non urgent,and that I should expect an appointment in 8 to 10 weeks,and to go home and forget about it.But as I had lost my mum to B.C many years ago I paid for a private mammograme and biopsie which showed invasive ductal and DCIS.I tend to go with what my oncologist prof Yarnold who is an expert in B.C (well I think he is)I have stopped taking medication at the moment for the depression,I said I would see how I go with the counciling first.I have googled citalopram and it says that it has very low effect if any on tamoxifen.But my oncologist still doesn’t addvise taking it.

best wishes love Mell x

Thanks Mell. Good for you, you did the right thing. I tried to go private after my second visit to the GP and was told by the private hospital that I would need a GP referral letter in the first instance. Unfortunately, I decided to trust my GP and did not go back to her for a private referral letter. Much to my cost. I’m doing lots of campaign work in the hope that what happened to me never happens again.

I don’t want to take citalopam if it has an effect on tamoxifen. Being a stage 3 I need all the protection I can get. I will do some googling and see what I want to do thereafter.

Many thanks for your support.


Hi, yes I had to get referrel letter before the private hospital would see me.My GP was not impressed when I asked her for one,and said she was sure there really was nothing to worry about, and was I sure that I wanted to pay as it would probably be a waste of my money.I said to her that I thought anything suspicious was meant to be seen in 2 weeks she said in her opinion she did not find anything that indicated cancer and the only reason she was refering me at all was because my mum had B.C.I dont know if waithing 8 to 10 weeks would have made a difference,mine was grade 2 but had already gone to lymphnode.

best wishes love Mel x

Heck! This is a bit of a worry. I’m on tam and fluoxetine, and have been for 8 months. I’ve just looked on google and now I’m a bit worried (Just one more thing to worry about) I will def be asking about this. The research I read about was published in 2005, so they must have a better idea by now…
Jacquie x

Dear Mel
Your must have been very intuitive - did you tell your GP what happened when you when private? I wish I had done the same thing. Although I guess you may often wonder if you had been caught earlier would your lymph node have been free of cancer. I also think about that. However, I cannot dwell on the past. What surprises me is how much the care varies throughout the country and how some people (like myself) found it almost impossible to get into the system. The system needs to be far more accessable for women of all ages and until this happens mistakes will continue to be made. An average GP Practice only sees approximate one case of breast cancer per year (as quoted to me by Macmillan and BCC) yet GPs have the power to prevent you from going further with your breast concerns. Campaigning helps but what campaign group wants to tackle the access/GP problem? I’m still working on it four years later.



Yes my instinct told me something was not right,and because of my mum I had been very breast aware.I didn’t have a lump as such it was more like a thickning,I think thats why my GP didnt think it was B.C.But my nipple was more flat and slightly pointing the wrong way this was what got me worried as I remembered my mums nipple being inverted when she had B.C.The next time I saw my GP was when I was having chemo and I developed thrush in my mouth.There I was sitting there looking and feeling rotten with no hair,eyebrows or lashes,she looked at me and said " I am so very,very sorry " I did feel a bit sorry for her, but then she started going on about how good the treatments are nowdays for B.C and I am lucky that I got it now and not 10 years ago as things have improved soo much.I didn’t have the energy for any reaction so I just smiled took my prescription and left.

love and best wishes mel x

My GP also apologised after saying she was pretty sure there was nothing wrong with my breast and putting me on an 8 week referral, mine was grade 1 and had already spread to a lymph node.

I was also assured by the breast specialist at the clinic that mey breast pain was “totally normal, totally hormonal” and told to go away and forget about it, he only agreed to refer me for an ultrasound because my grandmother had died of cancer aged 48, it was 2 months from seeing my GP to being diagnosed.

Dear Mel/Starflower

I find it interesting to hear that your GPs apologised. This may be because your outcome would have been the same albeit there was a delay in referring. No-one will know for sure. My case is quite different and being 4 years misdiagnosed has probably made quite a difference to my treatment and prognosis. My GPs have never apologised and even deny I asked for a mammogram which is not helpful to my psychological state.

Mel - it’s interesting you say you didn’t have a lump and it was more like a thickening. Did you have lobular BC? I ask this because it was lobular I had and I also did not have a lump. When I first went to my GP I had thickening and swelling under one armpit. She said it was an extention of my breast tissue, I had absolutely nothing to worry about, and refused me a referral. The next time I went I had thickening, swelling and two lumps under my armpit. I was told it was the remains of a viral infection. Again, on the third occasion I was told I had nothing to worry about and was refused a mammogram being told I was under 50 and therefore not eligible for the NHS Screening Programme. Through research I have found out that many GPs will refer women with thickening, dimpling, swelling or anything else that is of concern to their patient. However, there are some who only refer a lump. GPs need to be much better trained in recognising all the symptoms of breast cancer and not just lumps. Lobular and inflammatory do not show up as lumps. No amount of breast cancer awareness is of any use if you cannot get passed the gatekeeper.

Thanks for an interesting discussion.



I could feel a lump if I really poked about, but my GP couldn’t feel a lump and neither could the breast specialist - he said there was a thickening but no lump. Mine was said to be lobular initially but the pathology report said it was more suggestive of ductal.

It is very worrying how many women on here are refused referral by their GPs.

Dear Starflower

Yes, it’s shocking. However, I doubt very much if there are many cancer organisations that want to run campaigns for better GP training or a better system for referral. I’ve been trying for a few years now and although I do feel I’m getting somewhere it is not with the organisations you would expect. BCC must know by what is being said on this website and I would have expected them to take a more active role. I say no more.

Keep well.



Hi, mine was ductal,but was deep and behind my nipple.I have a friend who’s mum was misdiagnosed for bowel cancer,she went to her GP several times for over a year before he would refer her,and told her it was IBS. And in my daughter’s case we were told she just had a normal virus.I know it is difficult to diagnose some illnesses.But why dont they rule out the worst case scenario rather than assuming what the problem is(not sure if that make’s sense).

best wishes Mel x