pentobarbital will decrease the extent or result of pitolisant by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Check Carefully. Pitolisant exposure is diminished by 50% if coadministered with powerful CYP3A4 inducers.pentobarbital will minimize the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4