pentobarbital will lower the extent or influence of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Warning/Observe.pentobarbital will lessen the level or result of estropipate by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Monitor.Anticoagulants: Phenobarbital lowers the plasma levels of dicumarol (title For