Google " polymorphism CYP3A4 (it’s part of the P450 liver enzyme group) that metabolizes finasteride. (Finasteride is an “inhibitor”)
“These results indicated
that individuals might potentially have alterations in
their ability to metabolize not only testosterone but potentially
other pharmacores. Future studies will address metabolism
of clinically important drugs.” jpet.aspetjournals.org/content/299/3/825.full.pdf
The steroid hydroxylase CYP3A4 is the most abundant P-450 enzyme in the human liver, and CYP3A enzymes metabolize more than 50% of prescription drugs. The CYP3A4 gene is expressed in the liver, gut, colon, prostate, and breast. aje.oxfordjournals.org/content/160/9/825.full
Importantly, CYP-regulated drug metabolism is
prone to genetic variability that can result in an
enzyme with normal, low, or no activity. CYP
polymorphisms are responsible for observed variations
in drug response among patients with different
ethnic origins (5,6), which could be combined
with genetic variations in other DME, drug
transporters, and drug receptors. ljkzedo.com.ba/medglasnik/vol81/MGvol81.2011_18.pdf