Pentobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. pentobarbital will decrease the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. pentobarbital will decrease the level or effect of tolterodine by affecting hep... https://bookmarking1.com/story20303751/dice-buzz-su-pentobarbital-veterinario