pentobarbital will reduce the extent or effect of trazodone by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Observe.pentobarbital raises effects of ifosfamide by impacting hepatic enzyme CYP2B6 metabolism. Use Caution/Watch. Coadministration of ifosfamide with CYP2B6 inducers might increase metabolism of ifosfamide to its meta