Check Closely (1)istradefylline will improve the degree or outcome of diazepam by influencing hepatic/intestinal enzyme CYP3A4 metabolism.iloperidone increases levels of diazepam by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Check. Iloperidone is a time-dependent CYP3A inhibitor and may bring on amplified plasma levels of pr