Up to 21% of Asians are ultra-rapid 2D6 metabolizers, leading to: Rifampin is a nonspecific CYP450 inducer that may: Inhibition of P-glycoprotein by a drug such as quinidine may lead to: Warfarin resistance may be seen in patient with VCORC1 mutation, lead to: Pharmacogenetic testing is require by the U.S. Food and Drug Administration prior to prescribing: Carbamazepine has a Black Box Warning recommending testing for the HLA-B*1502 allele in patients with Asian ancestry prior to starting t...