pentobarbital will lower the level or influence of ethotoin by impacting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Keep an eye on.pentobarbital boosts effects of ifosfamide by impacting hepatic enzyme CYP2B6 metabolism. Use Caution/Check. Coadministration of ifosfamide with CYP2B6 inducers may possibly raise metabolism of ifosfamide to its m