[Becky]

Arimidex and Femara work in the same biochemical mechanism (to inhibit aromatase). Aromosin, the third AI, works in a different way to inhibit aromatase so many times, women will get the same side effects from Arimidex or Femara but not from Aromosin. That said, there are dozens on this board who switched from Arimidex to Femara (because of joint pain) and the switch was very worthwhile in that their pain was less or did not occur.

There is a huge trial that is ongoing testing the 3 AIs against each other in early breast cancer. By the time the trial is done, we will all be finished with our 5 years. In early bc, I don't think they will find a difference between the 3 drugs (with the exception of varying degrees of differing side effects).

However, in 2 different very small (less than 20 women) studies of women with bone mets, Femara worked better than the other 2 AIs but the difference wasn't statistically significant and trials with a larger population has to be used. Also, the researchers did not identify the pathology beyond being ER+ and PR+ women (don't know if they used any Her2+ women or not).

So - try Femara - all three drugs work well and you may not get the side effects you got from Arimidex. If Femara isn't better with the joint pain, or is worse, you can always try Aromosin or go back on Arimidex.

Cheers and Happy Mother's Day to all!