Istradefylline 40 mg/day amplified peak ranges and AUC of CYP3A4 substrates in clinical trials. This result was not observed with istradefylline twenty mg/working day. Take into account dose reduction of sensitive CYP3A4 substrates.atazanavir will increase the degree or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. U