Is all generic Tamoxifen equivalent?

indigo115

I have been on Tamoxifen for a little over a year. Had some hot flashes (more like episodes of sweating profusely) and slight vaginal discharge. I moved during the past few months, and when I needed to renew my prescription, I noticed that the pills I got were not the same as the ones I'd taken for about a year. I have noticed different side effects - mainly, decrease discharge and slight increase in breast tenderness. No hot flashes. My onc says that the active ingredients are the same in all generic brands of Tamoxifen. I'm wondering if anyone else has experienced what I have. Should I go back to the 1st type of Tamoxifen I had? I am not sure that this is working & I don't want to take something that will jeopardize my treatment.

NativeMainer

Generic medications have exactly the same active ingredient as the original brand name drug.  The only difference is in the fillers and other chemicals (preservatives mostly) that are used. What we sometimes forget is that all drugs are manufactured in large batches and it is impossible to guarantee a precise dose in each pill or tablet or capsule.  The FDA allows a small variation in active drug dose in each tablet and in each batch as long as the average dose in each pill is within a certain percentage.  For example, an individual 500 mg acetaminophen (generic) or Tylenol (brand name) tablet may have as little as 475 mg or as much as 525 mg.  When the actual dosage of each tablet in the batch is averaged the dose needs to be between 490 and 510 mg per tablet to pass inspection.  (These may not be the exact numbers, I used 5% as the leeway allowed, for some drugs it's as high as 30%)  Generics give us the same active ingredient in the same dose range as the brand name drug, but with different fillers, preservatives, coloring agents, and other processing chemicals. 

If you are still having side effects it's a good bet you are metabolizing the generic tamoxifen to it's active form.  Sometimes our bodies adjust to a drug and the side effects we experience change a little bit.  Also, it's a year later and your own personal hormonal balance may be changing, giving you a different SE set.  The stress of moving can also alter natural hormonal balances--that's why we skip periods during stressfull or highly emotional times.  All this interplays with the estrogen receptors that tamoxifen blocks. 

You might want to give the situation a little time to see if the side effect set you have goes back to what it was before, or ask your onc to test you for menopausal status and see if it's changed in the year since you started taking tamoxifen. 

veronica56

Make sure your going to a reliable source.  I always buy generic tamoxifen and it's worked really well.

coraleliz

Tamoxifen is only available "generic"(in the US,not sure about other countries). There are threads here at BCO about how some of us have tried to mitigate side effects by switching to a different generic brand. Some of us were successful, myself........not so. I've been on it for 15months & when my side effects lessen for a day or two, I start to wonder if I got a bad batch. But then my SEs always come back  ETA:I bumped another thread about this.

new2bc

Which generic Tamoxifen has less side effects? I have heard some people have lost their hearing with this medication. Please share your side effects and what brand you are using.