
Originally Posted by
Atomini
Irreversible means that the aromatase that it deactivates AT THAT TIME is permanently deactivated. Your body produces more aromatase, however. THe benefit of this feature of exemestane is that you will not get estrogen rebound if you suddenly stop administering the drug.
In comparison, Letro and Arimidex are NOT irreversible AIs, and if you discontinue them suddenly, the aromatase that they deactivated will then become active again and you will get estrogen rebound.
Makes sense?