<unk>  is metabolized by the liver enzyme CYP3A4. While the CYP3A4 inhibitor ketoconazole had no significant effect on<unk>  levels in a clinical trial, the strong CYP3A4 inductor rifampicin significantly cut<unk>  levels about in half (AUC −54%, Cmax −41% for a single dose), potentially compromising its effectiveness. Other 3A4 inductors such as carbamazepine and St John's Wort are expected to have similar effects. The clinical relevance of this effect has not been investigated. Estrogens probably reduce<unk>  effectiveness: It would usually be counter-productive to reduce the body's estrogen synthesis with<unk>  and then substitute estrogen with pharmaceuticals.
Exemestane
Anastrozole
Salvestrol
Hexestrol
Fosfestrol
Norendoxifen
Tamoxifen
Formestane