pentobarbital will reduce the extent or effect of irinotecan by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Keep an eye on. pentobarbital will lower the extent or influence of vinblastine by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Small/Significance Unfamiliar. pentobarbital and daridorexant both of tho