pentobarbital will lessen the extent or outcome of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Observe.Observe Closely (one)pentobarbital will reduce the extent or result of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Keep track of. Loss of, or diminished reaction to tofacitinib could