As zouzi indicated, these two drugs are very similar in effectiveness, and there is some evidence that they both are superioir in some ways to a third AI, Aromisin:
"December 14, 2009 (San Antonio, Texas) — New results coming from 2 mature trials with exemestane (Aromasin, Pfizer) suggest that this aromatase inhibitor differs slightly from the other 2 available products, letrozole (Femara, Novartis) and anastrozole (Arimidex, AstraZeneca).
Although all 3 are aromatase inhibitors, exemestane is a steroidal product that binds irreversibly to the estrogen receptor; the other 2 products are both nonsteroidal and are reversible inhibitors.
Concerning breast cancer recurrence, exemestane appears to be less effective at preventing early events, although it is effective at preventing later events, and it now appears that most of these events are in the bone, according to data presented here at the 32nd Annual San Antonio Breast Cancer Symposium (SABCS)."
Hi,
There are really no differences. between the two drugs.Both have the same results in reducing estrogen from the body.
Side effects are also similar,but some women tolerate one better than the other...
Best wishes..