phenobarbital will decrease the level or impact of eltrombopag by affecting hepatic enzyme CYP2C9/ten metabolism. Use Warning/Observe.Keep track of Intently (1)phenobarbital will reduce the extent or effect of tofacitinib by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Loss of, or lessened response to tofacitinib migh