Pentobarbital will decrease the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. pentobarbital will decrease the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. pentobarbital will decrease the level or effect of levonorgestrel oral/ethinylestradiol/f... https://bookmark-vip.com/story19926313/niet-bekend-details-over-is-nembutal-legaal-in-nederland