do you tamoxifen? (then read this post)

UPDATE: My CVS pharmacist just called me and she told me that there is a shortage in the Teva version of Tamoxifen, especially in the 30 day count bottles, which is what we get.  So my pharmacist bought a larger count bottle so myself and other women who use this particular store can get the generic that we can tolerate.  I am looking to poke around at Teva about this shortly.

Here is the note I am writing to the media relations people at Teva to shoot up the food chain:

Dear Teva:
I am a breast cancer survivor from Pennsylvania on Tamoxifen.  I have been on it for almost a year now (Teva’s generic), until my prescription was refilled 3 + weeks ago.  My CVS pharmacy then switched me to Mylan’s generic and the drug’s side effects ramped up – I had increased hot flashes, night sweats, moodiness,and sleep interruption. I also itch and don’t have any bug bites or poison ivy.
The sleep has been the worst.  For three weeks I have struggled to get more than 3 hours of sleep at a shot.  As you know, that is a very real side effect of women on Tamoxifen.  Sleep on your generic is about 6 hours at a time before I pop awake, which makes a huge difference in getting through the day and functioning.
I finally sat down to see what had changed in my life in 3 weeks and the only thing was a switch in generic of Tamoxifen from Teva to Mylan.  I put it out there on breast cancer pages I belong to on Facebook as well as my breast cancer blog, and discovered other women also experiencing the same thing within the same time frame.  All had been switched from Teva to Mylan.
So I called my doctors and my pharmacy.  What I was told by my CVS pharmacist this morning is that there is a shortage of the Teva generic, especially in the 30 day count which is what most women are prescribed.
I would like to know (a) what is causing this shortage and (b) how you plan to rectify the shortage issue.  I have read in the news recently of shortages in other cancer drugs across the board, but nothing with Tamoxifen.
Please…you have absolutely no idea what it is like to experience any of the side effects of Tamoxifen, and since I can tolerate your generic and my insurance will only pay for generic, please let me know when and how this problem will be addressed.  If there is a better supply, say with your Canadian/European arm, can the drugs come in from Canada?Europe to US patients and their pharmacies?
Thank you

Previously: As all my readers know, I have worked very hard post breast cancer to reduce stress, change my life, be more healthy, and so on.

One of the hardest things to deal with since my diagnosis is the Tamoxifen.  Now on it 3/4 of a year, my body was finally adjusting and I was learning to sleep again, and the hot flashes and night sweats weren’t so obnoxious.

Until about three weeks ago when CVS switched me from the Teva generic of Tamoxifen to the Mylan generic of Tamoxifen.  Many will argue that generics are generics, but ask any chemist or person with a background in pharmacology and they will tell you different generic manufacturers use different binders and other manufacturing agents.  They are never exactly identical.

I was so enjoying being able to sleep again that this has been a jarring experience and after only 3 1/2 hours last night and MORE night sweats and hot flashes I realized what had changed in the last 3 weeks was the generic Tamoxifen I was taking.  You see, before my prescription was at Rite Aid and they filled it with Teva’s generic.   When I switched to CVS because it was more conveniently located, the CVS filled it with Mylan’s generic. And I have been itchy.  I am never itchy. And I do not have poison ivy. Or bug bites.

I would like to know if any of the rest of you out there have had a problem when switched to Mylan’s generic formula of Tamoxifen.  Since I put a comment up on my Facebook page, I have already had one woman who is a friend and fellow survivor say that she just got switched by CVS this month too and is having the same issues as I am.

So I am guessing CVS has a deal going with Mylan.  Well my proescription plan wants me to just use a generic, so I want to use the generic that doesn’t make me nuts like this!

Here is what NIH says about the Teva generic:


Tamoxifen citrate tablets USP, a nonsteroidal antiestrogen, are for oral administration. Each tablet contains 10 mg or 20 mg tamoxifen (equivalent to 15.2 mg or 30.4 mg, respectively, of tamoxifen citrate).

Each tablet contains the following inactive ingredients: croscarmellose sodium, hypromellose, lactose (monohydrate), magnesium stearate, polyethylene glycol 400, povidone, corn starch, and titanium dioxide.

Chemically, tamoxifen is the trans-isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2-diphenyl-1-butenyl)phenoxy]- N,N-dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1). The structural formula, empirical formula, and molecular weight are as follows:

C32H37NO8      M.W. 563.62

Tamoxifen citrate has a pKa’ of 8.85, the equilibrium solubility in water at 37°C is 0.5 mg/mL and in 0.02 N HCl at 37°C, it is 0.2 mg/mL.

Here is what NIH says about the Mylan generic:


Tamoxifen Citrate Tablets USP, a non-steroidal antiestrogen, are for oral administration. Tamoxifen citrate tablets are available as:

10 mg Tablets. Each tablet contains 15.2 mg of tamoxifen citrate which is equivalent to 10 mg of tamoxifen.

20 mg Tablets. Each tablet contains 30.4 mg of tamoxifen citrate which is equivalent to 20 mg of tamoxifen.

Each tablet contains the following inactive ingredients: anhydrous lactose, colloidal silicon dioxide, crospovidone, magnesium stearate, microcrystalline cellulose and sodium lauryl sulfate.

Chemically, tamoxifen is the trans isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2-diphenyl-1-butenyl) phenoxy]-N, N-dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1). The structural and molecular formulas are:

Tamoxifen citrate has a molecular weight of 563.62, the pKa’ is 8.85, the equilibrium solubility in water at 37°C is 0.5 mg/mL and in 0.02 N HCl at 37°C, it is 0.2 mg/mL.

Anyway, fellow pals of the tale of the breast?  Have you been switched recently to a different generic of Tamoxifen, especially by CVS?  If you were on Teva’s generic Tamoxifen   and have been switched to Mylan’s generic Tamoxifen  and have noticed increased sleeping issues, hot flashes, and night sweats, maybe we are all onto something.

I definitely think I am as this is discussed on

May 31, 2009 10:54 AM gidget01wrote:

I actually had your situation…. I had been on the TEVA manufactured tamoxifen for 9 months and had no problems.  When my prescription plan changed, the pharmacy filled it with the Mylan generic. All of a sudden I started experiencing hot flashes which I had not had previously.  I thought it was odd because the active ingredients in both TEVA and Mylan are both identical, just the inactive are different.  I asked the pharmacy at the next refill if I could switch back to TEVA. They did and presto the hot flashes disappeared.  Strange but true…

Mylan has been under investigation by FDA in the past – in 2009   .  So it’s entirely possible their form of Tamoxifen is really crappy and should be off the market. Mylan had FDA warning on stuff in October 2011 and something in 2012 in January. In March 2012, they agreed to pay $7 million in a drug pricing deal in California. As far as drug pricing they had a similar issue it seems in Idaho in January.  Mylan CEOs seem to earn a lot and change up, too.  They are located in part close enough to Pittsburgh (Canonsburg ,PA), so the papers up there follow the company nicely.

Tomorrow is a very big day for me…it will get the separate post it deserves.  A year ago tomorrow I had my surgery.  A year ago tomorrow my tumor was removed with clean margins and nodes.

And today I made a new friend, a previvor who lives five miles or less from me.

About carla

Writer, blogger, photographer, breast cancer survivor. I write about whatever strikes my fancy as I meander through life.
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34 Responses to do you tamoxifen? (then read this post)

  1. Kristen N says:

    Interesting timing for me on this post…

    Came home from Rite-Aid this evening after filling my “lovely” Tamoxifen script to find it changed from Teva to Watson Labs…curious to see what may transpire?!! Only my third month though, not even sure I have actually begun to experience the height of all of the side effects.

  2. I received the following comment from a woman on a breast cancer board I belong to, and have further heard from other women who had similar issues when they had other life necessary meds switched from one generic to the other. Here is the Tamoxifen related comment:

    “My mom was on Tamoxifen for some years. When they gave her Tamoxifen from another “brand” she experienced many more side effects, including nausea. She asked for only the type she had in the beginning after that.”

  3. I will post this update in the body of the post as well. My CVS pharmacist just called me and she told me that there is a shortage in the Teva version of Tamoxifen, especially in the 30 day count bottles, which is what we get. So my pharmacist bought a larger count bottle so myself and other women who use this particular store can get the generic that we can tolerate. I am looking to poke around at Teva about this shortly.

  4. Pingback: one year. | ihavebreastcancerblog

  5. Laura Alway says:

    I had the opposite…lots of hot flashes with Teva and almost none with Mylan. My pharmacy seems to switch back and forth on the brand every few months.

    • Dawn says:

      Just read your message and wanted to tell you that my CVS just filled my Tamoxifen prescription with Mylan brand instead of Watson. I too, have had many serious symptoms since my brand was changed in 2013. Mylan informed me they are back on the shelves. I was able to get 10mg. 20mg not available as of yet. Worth trying again. Hope this helps.

  6. Pilar says:

    I, too, get along better with Mylan. I’m experiencing some incontinence . I researched it and found others with the same problem and Teva seems to be the culprit. I’ve been on Teva about two weeks and am headed back to the pharmacy this morning. Have been on Tamoxifin for 17 months.

    • Dawn says:

      Just read your message and wanted to tell you that my CVS just filled my Tamoxifen prescription with Mylan brand instead of Watson. I too, have had many serious symptoms since my brand was changed in 2013. Mylan informed me they are back on the shelves. I was able to get 10mg. 20mg not available as of yet. Worth trying again. Hope this helps.

  7. Lauri says:

    I found that as soon as I received “Novo” instead of Mylan, I could no longer sleep, have serious hot flashes etc_seemed to start right when the supplier changed…now trying to get switched back to Mylan but none avail right now apparently.

    • Penelope says:

      Hi Folks, This is the first time I’ve ever blogged so I am glad I’ve found this website. 🙂 My CVS had also went from the Mylan brand to Teva on me last August 2012 after being on the Mylan brand for over a year and a half. The Teva brand unfortunately exacerbated my symptoms more than the Mylan brand. But we’re all made different and handle things differently and Mylan just happened to work for me for over a year and a half. And I was really struggling with the Teva. So one day at my oncologist nurses appointment I brought this up about the switch in Tamoxifen and the nurses suggested I try the hospital pharmacy and talk to the pharmacists, which I did and now am glad that I did. If you’re trying to get a Tamoxifen that CVS or your pharmacy is having trouble getting-get ahold of your local Hospital Pharmacy. That’s what I did and they were able to get the brand from Mylan that I could no longer get at CVS. So now I purchase it from the Hospital Pharmacy and to this day my CVS still is not able to get it (Mylan). There are also more manufacturers of Tamoxifen “Watson” is another one that the Hospital Pharmacy may be able to get for you too. Thanks for sharing and listening.

    • Dawn says:

      Just read your message and wanted to tell you that my CVS just filled my Tamoxifen prescription with Mylan brand instead of Watson. I too, have had many serious symptoms since my brand was changed in 2013. Mylan informed me they are back on the shelves. I was able to get 10mg. 20mg not available as of yet. Worth trying again. Hope this helps.

  8. Kristin says:

    I am on Mylan and have been having serious problems with being bloated. Diuretics are not working. My feet and hands and body are so swollen. Big weight gain in one month. Anyone experience the same? What was the solution?

    • Quite frankly you should get into your doctor ASAP. I have had weight gain on tamoxifen, but I am not bloated and swollen like you’re describing. If you are talking about really swollen extremities like feet and ankles and hands, you really need to get into your doctor and have them do a workup on you. And ask your oncologist about switching the generic for tamoxifen you’re on.

  9. dokey says:

    Does any of you ladies know anything about getting Tomoxifen free or discounted? My niece lost her job and coverage and is on her last bottle!! NEED HELP PLEASE!! She’s a sweet person and I’m worried about her not getting her meds! I too had Breast Cancer, 13 years out!! Thanks Ladies!!

    • the writer says:

      She needs to go to her doctor, who can put her in touch with the manufacturer to see if there are discounted meds available. She can also contact nonprofits like living beyond breast-cancer and breast to see which ones offer grants to cover meds. Basically, while I appreciate you are worried for her, she needs to put on the big girl pants and do this herself.

      • the writer says:

        PS when you lose your job and you have benefits generally you are offered COBRA coverage. She can also check around in the state where she lives to see if there is public assistance available as far as health benefits

  10. dokey says:

    She has been through so much in the past 2 years, with the cancer, and a very bad, evil divorce! I know she should be doing this, but, I love my niece like a daughter! She was not offered COBRA nor can she gets insurance from the state. She has tried that already and she is trying to get insurance for her two little girls also because her X lost his job and won’t pay COBRA the $1400.00 to cover his own children. He is an EVIL person, believe me!! I am there for my family when they are in need to help in any way I can, that’s why I asked about this. Thanks for your info, hope I didn’t bother you too much.

    • the writer says:

      It didn’t bother me, but there is nothing I can do for her. I was left with no money, no health insurance and a dying dog a few years ago and I got myself health insurance and so on. She has to be her own advocate. She should talk to her oncologist who prescribed the tamoxifen. Divorce or whatever, I am truly sorry but she has to be her own advocate.

  11. dokey says:

    P.S. She can’t afford COBRA. She is barely getting by and paying her bills. I really didn’t expect to get the response that I got from you. I thought you were on here to help ANYONE? I won’t bother you on this site again!!

    • the writer says:

      lady, I write a blog about breast cancer. I am not here to pay people’s bills. I merely mentioned COBRA because a lot of people don’t know they can get it. Your niece has to do some stuff for herself. Like I said, she should talk to her doctors. The reason I said that is a lot of oncologists will try and steer patients towards solutions because they don’t want the patients to go off meds. also many states offer assistance.

      Furthermore, I suggested two non profits that I knew of that sometimes had grants and stuff so people can get a hand up sometimes.

      I don’t care if you come back or not. You offended me. I don’t have all the answers. I told you what I thought and made a couple of suggestions.

      You could always have a beef and beer kind of event to fundraise for her.

      Whatever. I tried, you didn’t like what I had to say and c’est la vie

  12. dokey says:

    Your all heart, aren’t you? Don’t email me any further. I am survivor for 13 years also but I guess that doesn’t matter either! Guess what, I’m done with the site. You would never last on a REAL SUPPORT SITE/BLOG! Adios!

    • the writer says:

      OMG lady you are a MESS! YOU signed up to follow this blog, no one in their right mind would e-mail you. I offer plenty of support, but I offer my opinion. You just happen to NOT like my opinion. I am thrilled you are a 13 year survivor but your comments leave a lot to be desired so kindly GO AWAY. I did not seek you out, you came to me.

  13. LaShawn says:

    OMG OMG! I got this 90 day supply Tamoxifen Citrate 20mg filled on 5/15/2015 (MYLAN). I too am with CVS and have been on TEVA brand for 11 months with the exception of one month Watson Brand. But this MYLAN has changed my life. But my symptoms are worse. I’ve been to the emergency room and everything. Hot sweats, off balance, dizziness, hot sweats even though I take vitamin E to combat them and it was working until recently. Feeling tired almost falling to sleep at the wheel. All of this of course leads up to anxiety which creates a whole new set of problems. I JUST GOT MY PRESCRIPTION TRANSFERRED TO WALGREENS. I called them and that’s the brand that they have (TEVA). CVS said they have to special order and they will leave a note for the pharmacy manager and they dont have any in the warehouse so it won’t be in until Monday. It’s Thursday! I didn’t take it last night with the suspicion that it was that brand change. Now I am not taking it tonight either. I felt slightly better today. I will follow back up with my results once I’m back on the medicine that works for me. The medicines are DIFFERENT! Don’t let them tell you any different!

  14. HSmith says:

    I have been on tamoxifen teva brand for over 2 years. No symptoms but an occasional hot flash. Three weeks ago was switched to Watson brand due to Teva shortage. Experiencing blurry vision constantly, can’t see TV or drive safely. Also ankle and top of foot pain. Gained 20 pounds, no bloating. Younger is swollen and peeling. Thirst is out of control, can’t get enough to drink. Also weak and shortness of breath. Went back to pharmacy and begged for teva. Got it yesterday. Hope it works and curious how long it will take to get better.
    H.S. in N.C.

    • Meeka says:

      Hi, Did you notice a significant difference when you went back to the Mylan brand? I’ve been experiencing facial angiodema and I’ve been told that it may be from the “fillers’ is the brand of Tamoxifen I’m using.

      • carla says:

        Yes I noticed a significant difference I had a horrible allergic reaction to the Mylan brand.

        And that is the thing the basic generic drug is the same but from generic manufacturer to generic manufacturer the binders and fillers can be different and in most cases are.

        Mylan is also a company that if you research it has had issues so I would suggest talking to your doctors. Mine had to specify with my pharmacy that I could only handle one generic without reaction and for me it’s the Teva generic.

  15. Ruth says:

    I can not take the Mylan version of tamoxifen either. I tried it for the past two months because Teva has been unavailable. The hot flashes and perfuse sweating have been unbearable. I am literally dripping like when I get off the elliptical after 45 minutes. I had the same experience two years ago when I had to take the Mylan generic due to Teva shortage. I am a pharmacist and the inactive ingredients can make a difference in side effects and an individuals ability to tolerate them. I never discount a patients concerns of how one generic makes them feels vastly different from another. The cost savings to the pharmacy nor the insurance is worth feeling so much worse especially with hormone adjusting medications. Please listen to your body and insist on the generic tamoxifen that works best for you. You should not force yourself to suffer or worse stop taking it because you are miserable.

  16. Madeline says:

    Hi, just came across your site while trying to figure out if other people had gone through what I just experienced. After a diagnosis of ILC in April, surgery in May, and 5 weeks of radiation over the summer, I started taking Tamoxifen at the start of September. I didn’t really notice much in the way of side effects though I had some itchy spots on my lower back which I thought might be bug bites. Then I went to have my prescription refilled at the start of October (they only give out 30 pills at a time). I noticed it was a different brand – Mylan instead of the Teva they’d first given me but it didn’t worry me much at the time, other than finding it odd that the pharmacy didn’t point out that it was a different brand – when I opened the bottle later on it was a clearly different looking pill and I wondered at first if it was the right kind. Anyhow, within three days I’d broken out in extremely itchy hives on my lower back. I stopped taking the tamoxifen at that point but the rash continued spreading, mostly to my legs, my arms, and my belly for the following two weeks. The visible part of the rash went away after a couple of weeks but I did remain quite itchy at times for another two weeks or so. No changes had occurred in my diet, or lotions, or laundry detergent or anything else so I feel quite certain that it is something about the Mylan brand fillers that caused this reaction, though as I said I had been feeling a bit of an itch beforehand so now I am very hesitant to get back on tamoxifen at all. Thanks for sharing your experiences – glad to know it’s not just me!

  17. h smith says:

    Mylan gave me side effects too, ask your pharmasist to get teva from another one of there chain stores. Mine was happy to oblige

  18. Phyllis Johns says:

    Looking for teva tamoxifen. I have had breast surgery,radiation,ahd have been taking teva tamoxifen for four years. It does cause me to have hot flashes, but I cannot tolerate Watson or mylan. Today I got something new to me called activis. Has anyone taken this? 1 20 17

    • carla says:

      No. And every major chain drugstore can buy generic tamoxifen from Teva. Hot flashes are side effect of any generic tamoxifen – you have been forced into a chemically induced menopause. I think you need to talk to your doctors

  19. SM says:

    I started on Mylan so it is my preferred brand I can not under any circumstances take Watson/Actavis, when Mylan brand was temporarily discontinued in 2013 I took Watson which causing severe bone and joint pain to the point that it froze my shoulder, they then gave me Teva. While the side effects were noting like on Watson they were still might worse than the Mylan. Mylan has since (as you know) been continued so that is what I’m back to taking. My oncologist states it’s the fillers in the different brands that people have a issue with and half the time they the patient doesn’t even realize why they are all of a sudden having issues with a drugs they have been on, I have been on Tamoxifen for 5.5 years and it’s been difficult to say the least in getting my preferred brand. People first do not understand the side effects from these, and for some reason even though there are plenty of forums, blogs, discussion boards and Facebook pages concerning the side effects the professional have yet to validate them, as with the bone and joint pain, it’s almost always a after thought and there are a lot of people that have that as a main side effect. I’m also one of the freaks that get every rare side effect as well, like hypertriglyceridemia.

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