phenobarbital will minimize the level or outcome of eltrombopag by impacting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Watch.Watch Intently (one)phenobarbital will lower the extent or outcome of tofacitinib by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Observe. Lack of, or reduced reaction to tofacitinib may well ha